| Author | Message | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 941 Registered: 1-2003 Posted From: 72.171.0.144  Rating: N/A |
Folks, Once again I throw myself upon the kindness of the vast resources here on the board. Today, pulling the westbound grade out of Albuquerque, we apparently blew the turbocharger. What I seek from this group (unless one of y'all are heading past here and want to lend a hand) is some information about what else we may have damaged, and what it is going to take to repair. The engine in question is an 8V92TA, DDEC-II, 475 horsepower. Description of problem We were pulling perhaps a 4% grade at 60 mph in 95+ heat on I-40 west of Albuquerque, heading west. We had just passed the Route 66 casino at exit 140, and I was not noticing any problems until mid-grade, when things slowed down as per usual on the grades. I had one eye on the road, and one on the DDEC temperature reading, which had just climbed to 204 (recently normal for us on grades in the heat). Cruise was set on 62, and as we just slowed down below 50 I was just about to cancel it, when the CB came to life with a report that "boy, that bus is smoking." Sure enough, a ton of white smoke was billowing out the back. A quick check of the gauges revealed everything normal except turbo boost pressure, which had dropped to zero. We immediately took the shoulder, where I made a quick call to friend and DD guru Virgil Cooley of PEDCO, to get his opinion on whether we could nurse it back to Albuquerque (30 miles), or if we had to stop immediately and get towed. His opinion was that we did probably blow the turbo, and that we faced a decision: risk further damage to the engine by running it, or risk damage to the coach with a tow (Virgil is very familiar with our hard-tow rig). But he felt that as long as we had plenty of oil, and oil pressure stayed above 40 psi under load, we would probably be OK for a few miles. We were not stopped in a safe place in any event, and so after the phone call we took a vote and decided we would nurse it along to the next exit (2.5 miles), make a U-turn, and then nurse it back another 7 miles to the casino, which is where we are now. We kept the coolant temperature below 190 and the oil pressure up at 40 the whole way, but the exhaust clearly got extremely hot (it melted through the trailer wiring harness), and we burned plenty of oil the whole way. Current Status We are well-parked in a truck stall at the Route 66 Casino Truck Plaza. There is still plenty of oil in the crankcase, although it looks like we lost maybe a gallon. There is oil underneath both airbox drains (usually, we have little to none there), There is also a pint or two under the muffler. We've called our tow service, Coach Net. They called around to all the shops on their list in Albuquerque, but no one is open today. They will continue and get back to us on Monday. If we make the decision to get towed, say to Stewart & Stevenson, it will not cost us a dime -- we are fully covered. However, there is always the risk that the coach will be damaged towing it that far, and pulling the axles is dicey at best on this coach -- if they damage the seals, it could take months to get replacements. Options
Questions
History In case it is important, I should tell you that this engine has 130,000 miles on it since new (1989). It has been in-framed twice in that time, both times due to dirt ingestion. Both in-frames included eight complete cylinder kits, rebuilt blower and rebuilt turbo (Garrett). The first in-frame also included eight injectors; the second time around, we only replaced a couple that looked to be bad. The last in-frame was perhaps 40,000 miles (two years) ago. In March of this year, we stopped by PEDCO (who did both in-frames) to have them track down a handful of oil leaks. We had also been seeing high silicon levels (but no wear metals) in the two oil samples leading up to that visit, and, wary of dirt issues from two previous episodes, asked them to check the whole air induction system. We also pulled another sample, which came back with normal silicon levels -- we never did figure out where the Si was coming from. While we were there, I mentioned that, subjectively, I felt like I had diminished power and some extra black smoke, but no issues were found on that score. Fast forward to June. I continue to have a nagging suspicion that we are suffering a power loss and excess smoke, but all DDEC readings are normal, as is fuel burn. As we climb into the mile-high zone of the intermountain west, I am noticing this more and more, and we are also running hotter than we think we should be. So we pulled into Stewart & Stevenson in Farmington, NM for a check-up. There we discovered a loose exhaust clamp upstream of the turbo, which could certainly account for all those symptoms: black smoke, low power, and higher temperatures, even though the boost pressure "seemed" to be in the normal range. That was less than 1,000 miles ago and we got a "clean" bill of health. After a while, even with 100,000+ miles of experience driving this very coach, I start to doubt my own judgment about these sorts of things, and thus, despite a continuing nagging feeling that we were putting out more black smoke than normal and suffering from reduced power, we chalked it all up to high-altitude operation, right up until today. So there you have it. We're stuck here on the Laguna Nation until Monday -- at least the casino has a pair of restaurants, and the truck plaza has a c-store. In the meantime, any and all feedback, comments, and suggestions are welcome. Please post them here, where it will all make Jim Shepherd feel a little less lonesome  -Sean http://OurOdyssey.BlogSpot.com | ||
| Tim Brandt (Timb)
Registered Member Username: Timb Post Number: 387 Registered: 10-2003 Posted From: 74.244.14.221  Rating: N/A |
Hi Sean, Let me start with I'm not an expert but yes if a turbo goes and it is blowing a lot of oil into the intake you will see it in the airbox drains as well as the exhaust. All that white smoke is the oil being burned. Also realize that a diesel does not have a valve to regulate intake air it controls itself from over reving by adjusting fuel. You are dumping lots of fuel in this case oil into that motor and could conceivably get to a point where you can't control it....then all you can do is try to stall it if it's a manual box or bail out and run as fast as you can away from the shrapnel that will be coming I'm sure some people more experienced than I with DD will jump in here as all my experience is with the mechanical injection engines. | ||
| marvin pack (Gomer)
Registered Member Username: Gomer Post Number: 556 Registered: 3-2007 Posted From: 71.53.155.14  Rating: N/A |
Sean; I can't be of much help here in Florida but, if it is blowing white smoke that seems to be another problem. Having been on the same road you are on and going to Farmington, Ship Rock area I know the mountains. I wonder if you have an injector problem? I thought when the turbo went it was mostly black smoke. I maybe wrong tho. If I could help I would be over in a minute,so all I can do is ask the Lord to help You. Done Deal. Gomer | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 857 Registered: 7-2006 Posted From: 75.211.220.71 Rating: N/A |
Sean... do not have the answer for you, but WE are Praying for you. Tough situation... Just went thru something similar a couple of weeks ago (240+ temps; weird things happening, but when we cooled it down, slowed a whole bunch...no stopping involved) it performed just fine and at the end of the trip, very little oil used. FWIW, Hang in there! (Proverbs 3:5 & 6) Best wishes for a "full recovery".... and demeanor Let me know if there is anything we could do for you...we're in Las Cruces. RCB | ||
| Peter River (Whitebus)
Registered Member Username: Whitebus Post Number: 130 Registered: 4-2009 Posted From: 67.77.201.181  Rating: N/A |
yikes. you say the boost pressure was 0. yet the turbo oil temps were within normal? when there's a oil seal in the turbo leaking oil, due to blockage/twist in the oil return line, all the symptom you describe would happen. It happened in my sports car, and it was only a matter of the oil clearing out of the turbos to return to normal. as for taking things off to "clean it", you can achieve the same by letting it burn it off (lots of smoke) bigger question is how in the world did you manage to ingest dirt twice to the point of rebuild? and your diagnosis of silicon in the oil sounds like you haven't really fixed that problem yet. all I can contribute here is that you check your oil return line from the turbo. slight kink will contribute to a LOT of leak into the turbos, especially under heat and strain. | ||
| John Lacey (Junkman42)
Registered Member Username: Junkman42 Post Number: 90 Registered: 3-2007 Posted From: 66.82.9.56  Rating: N/A |
Sean, pull off the intake hose to the compresor side of the turbo,ie inlet and see if You can turn the compressor wheel by hand. There should be no resistance to your effort to turn it. If it is stuck You can rest assured that it is toast. When replacing the turbo preoil the bearings in the turbo by preventing the engine from starting and turning the engine over with the starter until You have oil presure! The advice given on the board about return line is also a good point. There is also the possibility that the turbo failed because the oil supply line to the turbo is blocked. I used to overhaul industrial turbos and if I did the work Myself I would not mind a overhauled unit but like all rebuilt parts there is always a possibility of shoddy workmanship. Good Luck, John | ||
| Ralph Peters (Ralph7)
Registered Member Username: Ralph7 Post Number: 30 Registered: 3-2004 Posted From: 206.251.16.223 Rating: N/A |
First pull the intake off the turbo, look at the impellar take hold of it try to move it up'n down, in'n out, how does it spin? Is it,the impellar worn on the tips, also are the fins sharp or worn, your Si will wear the impellar to schreds. If the turbo is froze, and not broken impellar look at oil pressure line to turbo, the return is through the blower. I would remove the oil pressure( supply) and blow it out or replace it. | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 740 Registered: 8-2006 Posted From: 74.33.54.207 Rating: N/A |
Sean has a top mount turbo he has no return line the oil is returned through 2- 5/8 in holes in the top of the blower from the turbo good.He is blowing white smoke if the turbo siezed it would be black smoke.I sure hope he didn't blow a tip from a injector they do a lot of damage. luck (Message edited by luvrbus on July 18, 2009) | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 942 Registered: 1-2003 Posted From: 67.142.130.42 Rating: N/A |
No, engine coolant temp was normal. I can't tell what the oil temps were; I don't have a gauge for that, and DDEC-II does not monitor that.
I will look for that. However, given that this was a sudden failure, I am guessing it is either a catastrophic bearing failure, or turbine/impeller destruction. No changes have been made to oil plumbing in 40,000 miles.
First time was a complete disconnect of the intake plumbing upstream of the turbine, downstream of the filter. The duct had come apart in not one, but two places, and had also worn through in a third place. Second time was a bad air filter -- about a quarter inch too short for the housing. That let unfiltered air past the filter media. I am now very religious about checking the ducts and filters, and sampling oil at every change. The two samples that came back recently with Si showed no wear metals, which usually indicates gasket material, sealant, or additives rather than dirt. That might have come from the episode where we lost the power steering pump seal, dumping gallons of ATF into the crankcase.
and
Yes, I am well aware of what a broken turbo looks and feels like. Everything is still too warm to work on, but tomorrow morning I will be popping the hatch and removing the intake plumbing. I am 97% certain the turbo is toasted; I just don't know if this is a bearing failure or a turbine/impeller destruction event. Will find out tomorrow. Bigger issue for me is whether I can remove the turbo strictly from above, or if I need access from underneath for wrenches. I can get to the top easily, but coming in from the bottom is beyond what I can do in the field. BTW, I am guessing from symptoms that the turbo is completely seized. If it was just bearings, I'd still see some boost pressure and would have a little power -- I've got less power than a 250 NA, and zero boost, plus the exhaust plumbing got hot enough to melt things. That would point to the impeller not spinning at all. -Sean http://OurOdyssey.BlogSpot.com | ||
| Mark Renner (Boomer)
Registered Member Username: Boomer Post Number: 172 Registered: 11-2006 Posted From: 206.58.200.38  Rating: N/A |
If it was mine I would have it hauled to DD on a Landol trailer only. Yes, the driver will be aware that you are overheight a little, but you only have a little way to go. Your muffler is full of oil and that is a real fire hazard. It's happened before. The blower may have to come off too, there might be debris on the aftercooler depending on the extent of the turbo failure as well as blower damage. White smoke does not sound good at all. Should be black/blue with all that oil burning. Tow (haul) it Sean. | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 943 Registered: 1-2003 Posted From: 67.142.130.42 Rating: N/A |
Mark, Landoll is not really an option. No way to get this coach loaded without doing real damage -- the Landoll's angle of approach is just too steep. AFAIK, the only way to tow it is with a 10' underlift with wheel cradles, and pulling the axles. I am assuming the "white" smoke is burning oil at very high temperature. And, to be honest, the smoke seemed at times to be a combination of colors. But I would call it predominantly gray/white. Earlier in the thread Clifford said that black smoke would mean a seized impeller, and white smoke is better. But you are saying that black smoke would be better than white. So now I am thoroughly confused. I got the hatch open tonight, and in the morning I will be pulling the intake plumbing off to see what I can find. If I can get to everything I need, I might go as far as pulling the turbo off altogether -- hard to tell until I get the exhaust wrap off the thing. If I don't see missing chunks of turbine or impeller, I would assume there is little risk of blower damage or debris on the aftercooler -- is that correct? If I can get the turbo out myself, I will probably run it into Albuquerque and see if I can exchange it. Assuming no visible signs of damage or debris at the blower, what will I need to do about the oil in the exhaust? The muffler is a Cowl spiral unit, and has drain holes at the bottom -- I would figure that most of the liquid will be out by Monday, and there will just be a couple of tablespoons coating the insides. And, again, of how much concern is whatever oil is on the aftercooler at this point? -Sean http://OurOdyssey.BlogSpot.com | ||
| Peter River (Whitebus)
Registered Member Username: Whitebus Post Number: 131 Registered: 4-2009 Posted From: 67.77.201.181 Rating: N/A |
white smoke actually means the temperature is too low to burn off all the diesel. I don't think it has anything to do with the oil leaking. if it's oil burning off at high temperature, I would think it would be the blue smoke. of course it could also mean coolant leaking in and steam coming out, but that's the worst case scenario. to determine which, might want to smell the tailpipe and see what it smells like. | ||
| Roger Baughman (Roger)
Registered Member Username: Roger Post Number: 125 Registered: 11-2006 Posted From: 69.232.69.70  Rating: N/A |
Just a thought Sean. Is there a loading ramp somewhere near you? If you could get the bus high enough so the angle would not be a issue for the landoll. I wish I could help too, you have given us so much. Good Luck. | ||
| niles steckbauer (Niles500)
Registered Member Username: Niles500 Post Number: 940 Registered: 11-2004 Posted From: 173.78.29.189 Rating: N/A |
White smoke is definetely unburned fuel vapor - that is totally consistent with air starvation - whether that's good or bad news has yet to be determined - blue smoke would be oil and could be unburned fuel at low temperature (not the case here - we know the temps were high enough) - so you may have been lucky and not have torpedoed the mill - got my fingers crossed - good luck | ||
| Clint Hunter (Truthhunter)
Registered Member Username: Truthhunter Post Number: 213 Registered: 1-2009 Posted From: 24.129.232.232  Rating: N/A |
...good thing we have less than 40 feet to go for a "sleep on it" when these expensive events transpire. . . Driving on to the shop without knowing where all that oil is leaking from risks a run-a-way on your almost "new a third time engine" and that is not only much more expensive, but could lead to much greater dangers. Despite boon-docking at a gambling joint, you need to known the odds a little better for minimum informed decission making; to know if the oil leak is dangerously upstream of the cylinders ( coming from the bearing on intake side of the suspect turbine failure). Don't forget to check the coolant level as leaks can make for funny smoke issues. Perhaps you could get one of those shops to send out or find you a mobile mechanic to help make a more educated guess if this investigation gets beyond your fun level. Home is always the best place to be, that is one reason why chose wheels under our wee homes. Safety first my friend, don't chance blind luck when there are better odds to be had on this stressful crisis, you have already secured the scene from the imediate dangers of the roadside. Going back to share your two expensive maintenance negligence incidents (dirty intake) is very valuable basic education for the novice, more of that kind of sharing is always needed here, besides a good old "fess ups" does lead to one to good closure. | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 741 Registered: 8-2006 Posted From: 74.33.54.207 Rating: N/A |
Sean,white smoke is bad I don't think you have a turbo problem but am hoping you do. If the exhaust is wet on the exhaust pipe side only of the turbo it will be a seal but if it wet on either exhaust manifold feeding the turbo you have a major problem good luck (Message edited by luvrbus on July 19, 2009) | ||
| Cullen Newsom (Cullennewsom)
Registered Member Username: Cullennewsom Post Number: 102 Registered: 2-2009 Posted From: 98.201.161.214 Rating: N/A |
Sean, First, ditto what Tim Brandt about loading up the intake with oil. When I was a kid in high school, I got my feet wet on Detroits by working for a diesel mechanic on tugboats. Long story made short, I was told that if the engine "runs away" to throw all of the grease rags into the intake, then run (There was a screen to stop them from getting in the blowers). I've never seen one come apart from over-rev, but he had, and he seemed suitably impressed. From your description, My guess agrees that you've got a seized turbo, and that you've lost the oil seals / bearings. I guess you could have collapsed your air filter, and sucked it into the turbo, but probably not (because of the oil in the intake). As for what I would do, I would pull the air intake and verify the turbo is seized. If so, pull the turbo, and get it exchanged. Q1 - Burned or bent valves maybe, just a wild guess, don't fret too much. Q2 - Sounds like you lost the oil seals, was it using oil prior to failure? Is there now too much air intake restriction (too much restriction can cause the turbo to lose its intake side seals). This may be a clue to the cause. Q3 - Probably not since you caught it quickly. Remember Tim's advice. If you are worried, make sure that you have a way to block the air intake when you start it for the first time. Remove the air filter, and find a piece of plywood to cover the intake. Q4 - On my 6V92, removing the turbo is pretty easy. It's mounted top center. But I have more room. From the photos I've seen, things are jammed in much tighter on yours. I guess it depends upon how many elbow joints you have per arm. Tips: I have pivot head extensions, and I've never been afraid to cut, or bend wrenches. Your coach is way too pretty, so I know you don't carry grinders and torches (propane fish cooker burner maybe?) An ~~ 16" piece of EMT makes a nice cheater to help you remove bolts. Do you carry a sawzall / jigsaw with you? Might be time for a larger hatch, or even a new one! Last time I drained my coolant, I used my freshwater pump to pump into a barrel, from a 1/4" hose barb screwed into the draincock. Friends in Albuquerque to give you a ride? Shuttle bus from Casino? Rental car company might deliver a car to you. PEDCO might drive it out to you. | ||
| larry currier (Larryc)
Registered Member Username: Larryc Post Number: 255 Registered: 2-2007 Posted From: 205.188.116.203 Rating: N/A |
I'm hoping for the collapsed filter stalling the turbo and sucking a seal deal. If the intake side impeller is in one piece that would be a very good thing. If the worst happened and the impeller is inside the engine, its rebuild time again. Its all going to have to come apart so... The answer to the big question is what's that intake impeller look like? Then you can decide how to move foreward. If it grenaded it has to go to the shop. Guess since you already drove it, if the turbo wheels are gone you could put a bolt or nail in the supply line to the turbo and drive it to the shop. All the moving parts are going to get replaced anyway. Why can't you pull the driveline and leave the axles if you have issues there? Get a redneck 4 wheeler with a recovery tow strap to tow you on the back roads to the shop and just let it idle for air, but you would at least want to put some vice grips on the turbo supply line. (Makes it junk). If you keep using the engine in any capacity, make a cover for the outside air intake that will kill the engine just in case. | ||
| Cullen Newsom (Cullennewsom)
Registered Member Username: Cullennewsom Post Number: 103 Registered: 2-2009 Posted From: 98.201.161.214 Rating: N/A |
Yeah, about the axle pulling, what seals? Is it not paper gaskets? What axle do you have? Flat towing might be an option with bars and a heavy wrecker; but I'd be wary of the strap and a pickup truck, due to the grade you'll have to come down. If you pull the axles yourself, remember to have duct tape and sturdy plastic bags/sheet handy. Or cut and make a cover out of plastic/metal/wood. | ||
| john degemis (Degemis)
Registered Member Username: Degemis Post Number: 73 Registered: 3-2008 Posted From: 68.113.38.62  Rating: N/A |
Try to call Fernado at Prevost service 800-957-7386 You may be able to reach him today? He is the west coast Prevost service tech. | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 944 Registered: 1-2003 Posted From: 67.142.130.23 Rating: N/A |
Update: Sometimes, it's better to be lucky than good. I had just wrestled the exhaust blankets off the turbo (showing evidence of gas leakage -- soot -- around the inside edge, as well as a spot of fresh oil), had soaked the exhaust flange studs in WD-40, and was loosening the intake duct to check the impeller, when Louise, on her way to the laundromat here, spotted a "mobile mechanic" truck in the parking lot. We called the number, and Jim the mobile truck repair guy agreed to come over and have a look. I took it as a good sign that, when I told him it was an 8V92, he said "oh, you must be in a bus." Since he was already here, he agreed to work for just his hourly rate of $75, without the mileage charge. Pretty, good, I thought, for a Sunday morning. Jim had two things that I did not:
We chatted for a few moments, and he picked up basically right where I left off. The good news was that the impeller looked to be in good shape; so much so that, at first, Jim thought the turbo was fine (for just a heart-stopping moment). A few seconds later, though, he realized he could wiggle the impeller in the housing, and he predicted that the shaft was broken in two. Whew... that meant it was very likely a bad turbo and nothing else. He had the turbo out in less than half an hour. I figured it would have taken me two hours to do the same work, between going very slowly and methodically because I've not done it before, and having to work the bolts loose in cramped quarters with just hand tools. As it was, two of the exhaust flange studs came clean out, nut and all (the nuts came off the other two as normal). Sure enough, he was spot-on about the problem. The turbine/impeller shaft was broken in two, and the exhaust turbine was seized in the housing. This accounts for all the symptoms: high exhaust back-pressure preventing the blower from completely clearing the cylinders, unburned fuel likely continuing to burn inside the exhaust system, and oil flowing past the bearings and into both the intake and exhaust systems. Careful inspection of the impeller (compressor wheel) showed no significant damage, and so we agreed that it was unlikely any debris was sent into the blower. He was willing to hunt around to find a turbo today, but we also agreed that I would have to pay a considerable premium to get one on a Sunday. Later today I will get all the numbers I can find off the turbo (it's outside now, and just too bloody hot here in the sun -- I'll do it after sundown), and tomorrow morning I will start calling around. Recommendations for suppliers are welcome; also, if anybody knows exactly what turbo I need, let me know. I can load the turbo on my scooter and run it into Albuquerque for an exchange. I'll also need the exhaust flange gasket, oil return gasket, and blower adapter gasket (we could not get the turbo off the hose that leads to the blower without removing the adapter). I'm pretty sure I can get this back in on my own, but I may well call Jim back, just to have a higher confidence that it's been done right. We were very fortunate to luck into someone with plenty of DD 2-stroke experience. In addition to his rate, the round trip mileage charge will be an additional $60. At least he is willing to come back and put in parts that I supply -- if he acquired them, there would be a 30% mark-up. So that's the status. I'd like to thank everyone who has provided information or offered assistance so far. At this point, I think all I need is a source for a rebuilt turbo and the gaskets, preferably at something less than DD-distributor prices (I would be willing to bet Stewart & Stevenson can get me everything I need, for top-dollar prices). In the meantime, we'll be sitting here in the air conditioning, courtesy of Dr. Kubota, and surfing the Internet. I will answer some of the recent comments shortly in another post. -Sean http://OurOdyssey.BlogSpot.com | ||
| Cullen Newsom (Cullennewsom)
Registered Member Username: Cullennewsom Post Number: 105 Registered: 2-2009 Posted From: 98.201.161.214  Rating: N/A |
Sean, Knight's Auto Parts from Raton, NM (575) 445-9350 They may be able to give you some leads in ABQ. They are often open on Sunday. | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 945 Registered: 1-2003 Posted From: 67.142.130.23 Rating: N/A |
Cullen, thanks for all the help. But hey -- I resent those remarks! As a matter of fact, I do carry an angle grinder (DeWalt 120VAC model) with a grinding and cutoff wheels. I also carry a torch -- just a wimpy propane type, the sort one uses to solder pipes, but it would be enough to bend a wrench if I needed to. Have done so on more than one occasion. You're right about one thing -- the little propane bottles double as the emergency back-up gas for the grill (which normally runs off our pair of 2-gallon tanks).
No room in there, really, to swing a piece of pipe around. I do carry several cheater bars, though. And, yes, I have both a reciprocating saw and a jig saw, as well as a chain saw and a circular saw. All use the same batteries as my two drills (normal and right-angle) and big flashlight.
The hatch is already the entire size of the turbo "compartment" (the turbo actually sticks up into the bedroom by ~5" or so, and is surrounded by the wardrobe, a piece of which has to be removed to get to the "hatch").
Yeah, I could do any number of things to recover the coolant, except that repairs of that extent are frowned upon in casino parking lots. We're flying under the radar here, since all the work on the turbo is actually done from inside the coach, so it does not look like we've set up shop. I did have to sprinkle some cat litter under the muffler when things started to cool down, but so far no one has noticed that we're doing repairs here.
Actually, I've been having a discussion on that very topic on the other board. I think if we had to get towed on an under-reach, I would disconnect the driveline at the pumpkin -- less risky than pulling the axles.
They are Mercedes heavy-duty axles that were common in Europe. They have never been sold in North America, and only exist in this country on a few dozen coaches that were imported from Germany in the 80s. Parts for these systems are no longer available in the US. When I just had the differential pinion seals replaced a few months ago, I had to have them sent from England, where a supplier fortunately had some in stock. See here: http://ourodyssey.blogspot.com/2009/03/too-dang-lazy-to-move.html Unlike US axles, where the end of the axle is actually visible at the hub, and the bolt heads you see are actually holding the axle to the wheel, these Mercedes axles have dust covers, which is what you see when looking at it from the outside. The dust cover has a gasket. Once you get the dust cover off, the axle end is visible, and behind that is another seal intended to keep the rear end oil inside the unit. All of the seals for these systems that were ever shipped to the US were scrapped several years ago, as described in the post I linked above. In some cases, they are out of production entirely, so it becomes a matter of hunting around Europe or the UK until you find someone who has them. A real challenge. -Sean http://OurOdyssey.BlogSpot.com | ||
| Cullen Newsom (Cullennewsom)
Registered Member Username: Cullennewsom Post Number: 106 Registered: 2-2009 Posted From: 98.201.161.214 Rating: N/A |
Sean, I'm not second guessing your resourcefulness. Sometimes when one is in the heat of "battle" a fresh idea from outside helps. At least that's true for me. Feel free to dismiss without remorse, any advice from the peanut gallery which isn't helpful. It's just that you two appear to be so organized. We're envious of the worry-free lifestyle that you lead (in our imaginations)! I didn't know anyone carried around as much junk as me. Where do you put it all? You are approaching critical density, methinks. "I'm just checkin' mah oil again. Can't be too careful! Yup, looking forward to that buffet, and some slot machines. Do you still have a special deal for out-of-state visitors? Thanks for checking on us again mister casino-parking-lot-security-person! Shame about those seals getting scrapped. In any case, it's good to hear that you won't need to dig into your engine again. Good luck, enjoy the buffet, and all that. -Cullen | ||
| Ralph Peters (Ralph7)
Registered Member Username: Ralph7 Post Number: 32 Registered: 3-2004 Posted From: 206.251.16.223 Rating: N/A |
Check that oil supply line! It seized why, and ask Jim for an opinion. The line can collapse, I just went to a 8-71TA and we changed the line. | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 946 Registered: 1-2003 Posted From: 67.142.130.23 Rating: N/A |
Yeah... Gotta remember, though, that the coach was probably built with a Mercedes or Deutz (air cooled!), likely less than 300 hp. The 8V92 was squeezed into it after it got to this country, with a great deal of cutting and welding (and, probably, swearing). That's the way we got it. In fact, there was no access over the turbo when we got the bus. We re-framed all of the stepped-up area above the engine as part of the conversion, and installed two hatches that did not exist before -- one over the turbo, and another over the tranny. Very glad to have both now.
Well, since we are full time we have "all" our junk. Although we got rid of a lot of stuff before moving on board. I drew the line at tools -- we pared down to just one of everything, with duplicates of only maybe half a dozen hand tools (it's amazing how many #2 Philips screwdrivers one accumulates in a lifetime) -- but otherwise only got rid of things that could never be used on a bus (e.g. the drywall saw, or filter wrenches for vehicles we no longer own). I also sold every single one of my cordless power tools, which were all over the map (DeWalt, Porter Cable, Milwaukee, Craftsman) and bought one of those "systems" where everything uses the same battery and charger. Then we threw away all the boxes, cases, bins, etc. (with the sole exception of my trusty Western-Electric style tool case), and put it all into soft bags and tackle-style boxes. It all fits in the two outside "drawers" we use for tool and parts storage.
Good advice. We did look at it, and oil supply seems fine. But I will try to get it off completely and blow some air through it to make sure. The turbo was a rebuild, and who knows what the history is. It doesn't take much to lightly score a bearing, and it doesn't take much of a score to make a weak spot that will fail under load. -Sean http://OurOdyssey.BlogSpot.com | ||
| larry currier (Larryc)
Registered Member Username: Larryc Post Number: 256 Registered: 2-2007 Posted From: 205.188.116.203 Rating: N/A |
Nice Going . Don't forget to tell them that you have a good core! I'm sure your feeling alot better about things right now. Check the oil in the motorcycle! | ||
| Randy Davidson (Rdavidson)
Registered Member Username: Rdavidson Post Number: 25 Registered: 7-2006 Posted From: 32.178.97.249 Rating: N/A |
Sean -- what was "Jim the mobile truck repair guy"'s number and location? I, too, have an 8V92TA with DDEC-II and try to collect as many resources as possible as they come up. This link has several, thanks folks. Randy | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 947 Registered: 1-2003 Posted From: 67.142.130.25 Rating: |
Another update: First off, many, many thanks to all the folks who have come forward with advice, support, information, and outright offers of assistance, and especially Kevin ("zeroclearance") who is a turbocharger expert by trade and spent hours on the phone with me today talking me through various things. I spent most of the morning on the phone trying to locate either a complete remanufactured turbo, or a new "cartridge" (entire center section, including turbine wheel, compressor wheel, shaft, bearings and bearing housing, and compressor backing plate, all factory assembled and balanced). We nailed down a Reliabilt remanufactured unit early in the day, but it was in Denver, and, at ~65lbs, I was looking at a good deal of freight to get it here overnight. In the meantime, Kevin made some rather convincing arguments in favor of disassembling the one I have and putting a new factory cartridge in. For one, all the parts would be factory new and factory balanced, as opposed to a re-man where most of the parts are of unknown history and possibly only cursory inspection. For another, removing the turbine housing would possibly reveal more information about the cause of the failure. While Kevin (and others) were working on tracking down a cartridge, I made arrangements with local bus nut Eddie, a contact generously provided courtesy of Clifford ("luvrbus"), to come over to his place north of town and use his parts cleaner and bead-blaster to prep our existing housings. I then set to tearing the turbine side apart. Notwithstanding having heard from several people that getting the turbine housing off would be the biggest challenge, possibly requiring a torch and a hammer (and so I had prepared by hauling out my propane torch and 2-lb deadblow), the thing fell apart in my hands as I undid the clamp. That might explain the signs of exhaust blow-by we had seen aroung the clamp area. The turbine wheel was extensively damaged, and, of course, we were looking for tell-tale signs of Foreign Object Debris (FOD) damage, which would indicate that bits of rings, or maybe even valves, were spitting out of the engine and caused the failure. While the wheel damage was not inconsistent with FOD, there was no matching damage in the throat of the housing, and the bent vanes on the turbine might easily have come from impacting the housing after the shaft let go. The only way to tell for sure is to pull the heads off, or put a new turbo on and start 'er up. Another turbo will actually be less money than pulling the heads, so we have our fingers crossed that it is not FOD, and we're just going to slap a turbo on. In the process of diagnosing all this, we put up a photo album showing the old turbo just before, and just after removing the turbine housing, including turbine wheel photos, here: http://picasaweb.google.com/louise.hornor/July202009TurboInterior# After nailing down plans to do the cleaning and bead-blasting, and almost past the deadline for ordering the Reliabilt today, I got a follow-up call from Kevin, who had discovered that completely new, factory balanced cartridges for this model are discontinued and no longer available. I could have a Garrett OEM cartridge that was "partially remanufactured," or an aftermarket part of unknown alloy quality from Rotomaster, or a cartridge assembled by some guy in the Midwest out of new Garrett parts, all for the same price, around $800 or so delivered, with no warranty. If I went that route, I would also still be faced with a couple hours work cleaning and media blasting the housings, and then I would have to assemble the whole thing correctly when I was done. At this point, the Reliabilt, which came with a 12-month warranty and would cost me about $991 plus tax, after core, started to look like the better option. We ended up ordering the Reliabilt from Stewart & Stevenson, but, instead of having it sent next-day UPS for $225, we are having it sent by bus. If the Denver office got it in time, it should be at the Albuquerque office tomorrow, and shipping should be less than $80. With any luck, I will be able to pick this up at S&S tomorrow morning, and have it back in the bus by the end of the day. Worst case, we should have it sometime Wednesday. I will carefully check oil supply and return lines for obstructions, and pre-lube the unit with STP before installing it. Kevin has given me some explicit directions for breaking the unit in, which will keep us right here for several hours after installation. I will post another update when the repair is complete and we know whether or not it is the final solution of this problem. And now, if you'll excuse me, I hear the siren song of the casino buffet... -Sean http://OurOdyssey.BlogSpot.com | ||
| Clint Hunter (Truthhunter)
Registered Member Username: Truthhunter Post Number: 221 Registered: 1-2009 Posted From: 24.129.232.232 Rating: N/A |
...cleaning out possible lose FOD might just save the new turbo if it is practical to start the engine for a few seconds before installing, without making fire happen outside the engine, if you can do this , have a fire suppression at hand and observe what is ejected as best you can, thinking things threw first... | ||
| Cullen Newsom (Cullennewsom)
Registered Member Username: Cullennewsom Post Number: 109 Registered: 2-2009 Posted From: 98.201.161.214 Rating: N/A |
That's the way, you only have to pretend to gamble! They'll never suspect a thing. How about that expert turbo break-in procedure? New thread perhaps? After breakfast, of course. (Message edited by cullennewsom on July 21, 2009) | ||
| Peter River (Whitebus)
Registered Member Username: Whitebus Post Number: 132 Registered: 4-2009 Posted From: 208.54.14.5 Rating: N/A |
if chunks of stuff came off the engine, wouldn't it make a death rattle? hope that never happens to me, I don't think I am brave enough to take major components off... think positive | ||
| Clint Hunter (Truthhunter)
Registered Member Username: Truthhunter Post Number: 223 Registered: 1-2009 Posted From: 24.129.232.232 Rating: N/A |
I use to attend the odd casino , just to observe the strange states of being the one arm bandits patrons were participating in, would spend exactly one quarter every time to "keep the faith", now just try & find one that accepts standard issue canadian 1/4 coin currency up here . It is as if they were one to me getting on to them, so they changed what the machines would take (only in canada ehy), Never found one with a courtesy buffet up here though, guess it is time to come visit U-ALL & taste the easy life. Is it kind of like boon docking in a walmart too ? | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 949 Registered: 1-2003 Posted From: 67.142.130.40 Rating: |
OK, here's where we stand now on the turbo situation: The executive summary is that it appears to be completely fixed, and it also appears that it was nothing more than what we originally suspected, a blown turbo. For all you die-hards, the longer version is as follows. As I wrote here yesterday, we decided to order a Reliabilt reman from Stewart & Stevenson, and it came down from their Denver location overnight by bus. I called the Albuquerque office around 11 this morning, figuring I should have already heard something from them, and they informed me that it had just arrived. We loaded the old turbo on the back seat of my scooter and headed the ~20 miles back to town, avoiding the freeway by staying on old Route 66. Sure enough, S&S had the turbo, and it was the correct item. Unfortunately, the gaskets never arrived. No matter, since checking the order revealed they had ordered the wrong gaskets anyway. It soon became apparent why -- it took three different parts clerks and a service manager, plus myself, combing through three different parts books, to find the numbers for the correct parts. The issue has to do with the turbo being top mounted, with the oil drain coupled directly to the blower cover. Most of the exploded diagrams show an oil return tube, which I (and most bus installations) don't have. The seal for the oil drain is listed on some parts manifests, but it does not show on the diagrams, nor is its function listed on the manifest. Nearly two hours later, we had tracked down part numbers for the oil drain seal and the blower adapter gasket; the exhaust flange gasket was the easy one, and they had produced one within the first few minutes. They turned out to also have the drain seal in stock. Unfortunately, the blower adapter gasket was not, nor did anyone else in town have one. At least this was the least critical of the three, and it can be replaced later if need be without having to remove the turbo. We loaded the new turbo, the gaskets, and a gallon of 40-weight back onto the scooters and headed back to the casino, where I arranged to meet Jim the mobile truck repair guy. He was so efficient at getting the thing out, I decided to enlist his help putting it back in, too. As it turned out, he had to wrestle with it for nearly two hours to get it back in. Everything is tight in my engine bay, and getting the exhaust flanges, the exhaust pipe, the intake elbow, and the blower adapter to all line up and cooperate was a challenge. I had to open up the access hatch through the radiator intake so we could tug on the exhaust plumbing, and Jim ended up loosening the turbine and compressor housing clamps on the new unit to tweak the clocking to get it all to fit. eventually we had it all back in place, and then started pouring 40-weight into the bearing through the oil supply hole. Hmm... the oil does not seem to be going in. Nope -- it's just sitting there in the fitting. Even spinning the compressor wheel is not getting any oil to drain. After probably ten minutes of this, we decided the tiny orifice at the oil supply was clogged, most likely with assembly grease. We threaded an air fitting into the supply hole, and a quick blast of compressed air cleared the obstruction. After pouring a few ounces of oil into the bearing from a squeeze bottle, we re-attached the oil supply line. From the rear switches, which allow for cranking the engine with the fuel solenoid closed, I bumped the engine around a few times in short pulses -- so many folks have warned me about a blown injector tip, that I was worried a cylinder could be full of fuel and hydraulically locked. But there was no resistance at all. So I cranked it three or four times for close to ten seconds apiece, closely spaced, to get some oil flowing up to the bearings and purge any air from the supply line. Then I set the switch on run and cranked it again, and it immediately lit off. I noticed two things right away. The first was that I did not get a big puff of white smoke when it started -- we've been seeing such a puff of smoke on start-up for several months now, and it is one of the symptoms I have reported every time we've had anything done on the engine. We've now fired up three or four times today, with no smoke evident on any start. The second was that things sounded smoother than they have in a while, and the exhaust looked and smelled cleaner. All good signs. After checking for leaks, shutting down, and rechecking clamp tightness, we declared victory and I paid Jim for his time -- two hours, plus travel. We then buttoned the coach up, loaded the scooters, and set out around the parking lot on a low-speed test drive. Kevin (Zeroclearance) had strongly recommended getting everything up to operating temperature (and then back down to cold again) three times before putting any real load on the turbo, and so we kept speed and acceleration down, watching the boost gauge to try to keep it under 2 psi (we hit 3 psi occasionally). I stopped occasionally to check for smoke and read the temps with an IR gun, but all was normal at every stop, other than oil spitting out of the exhaust and the muffler drains. I expect to be puking oil for the next fifty miles, until whatever's left in the exhaust and the airbox finally burns off or spits out. After half an hour or so of "road" time (we made it as far as the historic Rio Puerco bridge), during which I noticed subjectively more power and less black smoke than we've had in quite some time (even at these very low boost levels) we parked for the night in the casino's RV lot, blissfully out of range of the incessantly idling trucks. After dinner, when all had cooled down, I popped the hatch to check all the clamps and look for leaks. What I found was that Jim had tightened the clamps on the outlet hose with the jackscrews too close to the steel supports for the top of the turbo compartment. We've had problems in this area before (see http://ourodyssey.blogspot.com/2005/05/duct-between-turbo-and-blower-showing.html), and so I loosened the clamps and rotated them 90° for clearance. When I did this, I noticed two things; one was that there was a ripple in the hose, because the clocking of the compressor housing had the outlet just a tad out of line with the blower adapter inlet. The second was that the hose looked torn in exactly the same spot as shown in the photo I just linked. With both hose clamps loose, I was able to loosen the compressor housing v-band and inlet duct, then gently tap the volute around a couple degrees with a plastic deadblow, taking care of the first issue. Without removing the adapter, however, I could not remove the hose to see if the tear went all the way through. Moreover, I was afraid that I could worsen the situation by trying to remove the hose. What I ended up doing was to tighten up all the clamps, fire up the engine, set the high idle to get enough compressor speed to bring the pre-blower boost pressure up above atmospheric (at extremely low compressor levels, the blower can clear the air as fast as the compressor provides it, yielding 0.0 boost, or just atmospheric pressure). Then I sprayed the hole with soap solution, just as one would when looking for air line leaks. No bubbles, so we think the hose is intact, and the tear we can see is just in the outer jacket. We will order a new hose and replace it as a precaution the next time we pass a Detroit shop. As long as the engine was now already running, I closed up the hatch and we let it come all the way back up to temperature before shutting down for the night. Tomorrow, we will do one more hot/cold cycle before we leave; during that warm-up I will connect my DDR and run the injectors, just to be certain we are firing on all cylinders, to borrow a phrase. If all seems well, we will clear out of here and resume our previous route west to Phoenix. At this writing, it seems as though we did not have any deeper problem, such as blown injector tips, or catastrophic destruction of rings or valves becoming FOD and hitting the turbine. I can't rule out FOD as a cause -- it's possible something such as a rust flake or a clot of coke got knocked off into the exhaust when S&S in Farmington repaired an exhaust clamp, for example. But I am inclined to believe that what really happened here is that the turbine wheel became slightly imbalanced many moons ago, possibly due to FOD but also possibly just due to manufacturing tolerance issues -- it was a rebuilt unit to begin with. Over time that imbalance caused irregular bearing wear, and the turbine has been wobbling in the bearing for several months. Eventually, the edge of the journal scored the shaft, creating a weak spot right where the turbine wheel attaches. It was then only a matter of time before some combination of heat, load, and speed caused the shaft to shear along the score line. The extensive damage to the turbine blades then occurred almost immediately as the now loose turbine wheel ricocheted around the housing. I will report back here once I have actually brought the engine into the powerband and the boost levels up into the high teens, and let you know how it's running. But based on testing so far, I believe we will be back to 100% normal operation. -Sean http://OurOdyssey.BlogSpot.com | ||
| Clint Hunter (Truthhunter)
Registered Member Username: Truthhunter Post Number: 228 Registered: 1-2009 Posted From: 24.129.232.232 Rating: N/A |
hum...the new absence of that chronic mystery "puff of white smoke " problem makes me wonder about bad bearing seals: leakdown when shuting down of engine, turbine oilleaks onto turbine, coking up on lowest blades, causing random temporary imbalance until finally the catastrophic failure from to many repeats of this flaw. Just a wild guess without looking. Third time should be a charm they say; so then , may you get a gillion miles on this last in-fame & new turbo , cyclops O/Operator ! Those cell phones can make good tool boxes some time they also say! Happy & safe busing | ||
| Chuck Newman (Chuck_newman)
Registered Member Username: Chuck_newman Post Number: 383 Registered: 1-2005 Posted From: 99.153.84.192  Rating: N/A |
Sean, I've been off line a few days and just read through your ordeal. I was glued to the posts like a mystery novel. Seriously. I'm happy you're back on the road after finding and repairing much less damage than it might have been. And at less cost than it could have been. I have a nagging fear of turbo problems and the damage they can inflict, from various reads. Through all this, have you set any new benchmarks for "indicators" of impending turbo failure? Such as white smoke, and turbo boost anomalies? Do you feel observing engine oil temperature would have helped foretell the malady? You mentioned heat damage. Do you think a Pyrometer would have helped in an earlier notification of the problem? My bus doesn't have one (like most), but I've been thinking of installing one, but several "experts" have said "naah, a bus don't need one". What is your opinion? I've saved this thread as one of the more important and instructional write up from you and all the contributors. Again, I'm sorry it occurred, but thankful of the outcome. And appreciative of all the detailed information in your writings, made under rather stressful conditions. As you said, thanks to Dr. Kubota, but don't forget Ms. Motosat. | ||
| David Evans (Dmd)
Registered Member Username: Dmd Post Number: 343 Registered: 10-2004 Posted From: 173.77.231.123  Rating: N/A |
i have to echo Chuck's post, great read from incedent to resolution. I also went thru your Odyssey web site and floor plan. Nice site and excellent post. Good luck and safe journey | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 950 Registered: 1-2003 Posted From: 67.142.130.35 Rating: N/A |
This will be, I hope, my final update on the turbo repair. Tonight we are at a picnic area on US-60 west of Quemado, NM, some 140 miles from where we started the day. Aside from blowing huge quantities of blue smoke at the beginning, tapering off steadily throughout the day, and the fact that the whole coach now smells like burning oil, we have had no problems or issues. I have tried to be fairly gentle on the turbo while we seat the bearings and seals, but, subjectively, we have normal power now, at least as normal as it gets at 6,000-7,000' altitude. This morning, during my third and final warm-up/cool-down cycle, I plugged in the DDR to check on everything. Specifically, I checked injector response, which looked good on all eight cylinders, ranging from 1.07 to 1.17. I also ran the injector cut-out test on all cylinders at idle as well as 1,000 rpm, and all injectors elicited a response, with pulse width increasing by 0.2 to 0.4 for each cylinder. For those unfamiliar, what this latter test does is to first report the amount of fuel being provided to the cylinders in the form of "pulse width" (PW), the amount of time the injectors are commanded to inject. Then it shuts off the injectors one at a time and reports the PW as each injector is off line. The idea here is that when a cylinder that was contributing real work gets turned off, the DDEC will have to increase the PW to supply more fuel to the rest of the cylinders to carry the load. If you turn off one injector, and there is no resulting change in PW, that means that that cylinder was not doing any work, which could mean a bad injector (or a number of other problems). I am interpreting the results, being fairly consistent across all cylinders, as meaning that I still have all eight injector tips, and all the exhaust valves are intact. I'm not conversant enough with these sorts of tests to rule out any other problems (low compression, marginal injector, etc.), but I am fairly confident at this point that the turbine failure was not due to FOD originating in the engine. While we were driving, Louise reported that the turbo sounded "rough" and that it made much more noise than the old one. That's cause for some concern, but not too much, yet -- I still have not replaced the heavy exhaust blanket over the turbine housing, nor have I secured the hatch (which involves caulking it, screwing it down, and replacing the 1/8" vinyl flooring over the top), and both of those things would attenuate the sound considerably. In fact, Louise later reported that the sound was lessened when she stood on the hatch. I have been asked whether there might have been something I could monitor that would have provided early warning of this impending failure. To be honest, I don't know. I don't suspect I would have noticed anything unusual on an oil temperature gauge, or even exhaust pyrometers, that would have led me to check on the turbo. Even the boost readings seemed normal right up until failure, and any changes in those sorts of readings would have been so gradual over time as to be unnoticeable -- sort of like putting a frog in cold water, and then boiling it. That said, I sure do wish I had pyrometers. Separate pyrometers for each manifold would have given me the confidence ahead of time that I did not have a single-cylinder failure of some sort. Also, they might have alerted me that the exhaust was getting hot enough to melt things (turns out, the thermoplastic wires were OK -- I only melted the slit loom). Again, I would like to thank everyone here for their help -- this board is a fantastic resource, and it is this kind of selfless outpouring of assistance that has kept me here, usually answering questions, long after my bus was completed. -Sean http://OurOdyssey.BlogSpot.com | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 951 Registered: 1-2003 Posted From: 67.142.130.35 Rating: N/A |
Sorry, I forgot to answer this. Here it is: Jim Taylor A Anytime Anywhere Albuquerque, NM 505-217-9335 http://www.anytime24hour.com -Sean http://OurOdyssey.BlogSpot.com | ||
| marvin pack (Gomer)
Registered Member Username: Gomer Post Number: 562 Registered: 3-2007 Posted From: 71.53.155.14 Rating: N/A |
Glad to hear the GOOOOODD report Sean and thank God for no other problems. I hope the rest of the trip goes uneventful. Gomer | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1567 Registered: 10-2003 Posted From: 71.58.110.9  Rating: N/A |
with all that heat blanket, make sure you always allow 5 minutes of idle prior to shutdown. Otherwise you can risk the oil cooking in the bearing area of the turbo, turning into coke and result in shortened turbo bearing life from oil starvation. | ||
| David Dulmage (Daved)
Registered Member Username: Daved Post Number: 256 Registered: 12-2003 Posted From: 142.46.199.30  Rating: N/A |
Sounds like your called the right shop when you contacted Jim Taylor. Thanks for posting the details. DaveD |
