| Author |
Message |
LABryan (63.197.32.204)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 25, 2004 - 1:05 pm: | |
Just picked up my 90 Prevost with 8V92DDEC (about 30kmi on factory rebuilt) with Allison HT755. Drove about 4000 mi from FL to northern WI then back to L.A. in two weeks. Changed oil, filters, belts and coolant before trip. Had a fantastic trip. Everything was great except for excessive engine heat. Water temp is 190 on flats in 75-85 ambient temps at highway speeds. Temp goes to 195-210 in higher outside temps on flat freeway and goes to 215 and above on desert climbs. Had to take that long climb from Needles CA on westbound I40 at about 35mph in 3rd gear yesterday to manage temp. (Sorry if that was you behind me in the MCI102) I don't really mind driving slower to manage heat, but if other busses, motorhomes pulling cars and 18 wheelers are blowing past me with no trouble, it seems that something must be wrong. I was not towing anything this trip, but plan to pull my VW Passat on future trips.
My bus converter's (Country Coach) manual says they addressed known 8v92 heat issues by installing extra large radiator and fan (they are huge!). Heat buildup was most noticeable when the turbo was pulling hard on hills. Anything over about 7 lbs and the temp needle starts to climb. I know I could add misters, but this is not an intermittent issue. Any suggestions? Thanks!
Bryan |
Geoff (Geoff) (66.238.120.3)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 25, 2004 - 1:24 pm: | |
Get a laser temperature gun and start checking various spots on your engine and radiator and see if you can find a flow or cooling problem. Also, the laser temp gun will tell you if your inside temperature gauge is accurate to begin with. A good time to check all this would be after a moderate climb.
--Geoff
'82 RTS CA |
Robert Wood (Bobwoodsocal) (4.46.99.46)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 25, 2004 - 1:31 pm: | |
The hill west out of Needles is a nasty one, I know it well. Have you had the radiator looked at? Maybe needs rodded out? hope you get it worked out. Congrats on the new coach! all the best, Bob |
David Anderson (168.215.176.182)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 25, 2004 - 3:00 pm: | |
I pulled my radiator out of my Eagle 10 (6v92) in February and had it rodded and cleaned. It solved my problems. I paid about $230 to have all that done.
David |
Jim Ashworth (Jimnh) (172.156.61.171)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 25, 2004 - 4:35 pm: | |
Those temps are not normal for an 8V92 500hp Prevost. You should be able to run floored up those hills with the temp at 195 deg.
The 500 (vs 475 hp) requires the larger radiator. I believe it is 36" rather than 34". You should also have a plastic 9 blade fan.
All the other usual diagnostics apply, ie, coolant, tstats, water pump, transmission fluid level, etc. Also check the mechanical temp gauge in the engine compartment and compare that reading to the dash after a good hill. It just might be the gauge or sending unit is faulty.
Good luck, it WILL get better.
Jim |
Ed Jewett (Kristinsgrandpa) (4.224.190.64)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 25, 2004 - 9:40 pm: | |
Also might check anti-freeze mixture. I've heard that 50-50 mix cools better.
The only overheating problems I've ever had was on a Bronco. Bought a Prestone flush and fill kit and flushed it. When it was done the inside of the radiator was shiney and looked new. I don't know how that would work on a DD. Has anyone tried it? Or have any info.
Later,Ed. |
Henry Draper (67.168.33.213)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 25, 2004 - 10:31 pm: | |
Congrats. on your new toy.
All the advice you've received so far is good. Missing is what I did when I founc myself experiencing the same symptoms you mention in my 8V92 (450 hp).
I steamcleaned the radiator! Problem solved--atleast kinda' solved! (I was pushing 200 on the flats, with an ambient temp. of 90-95` Cleaning the radiator dropped it down to 180-185 on the flats` I still had to watch the temp gauges on the climbs, but I'm used to that.)
It was truly impressive how much dirt came out of the radiator!
Good Luck
Henry Draper
'64 Eagle
Edmonds, WA |
madbrit (67.136.98.31)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 25, 2004 - 11:43 pm: | |
Bryan,
Make sure the seals around the outside edges of the radiators and the squirrel cage compartment access door are all good. If not, the air will take the easy route and by-pass the radiators.
Peter. |
Jim Ashworth (Jimnh) (172.140.40.123)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 26, 2004 - 8:24 am: | |
Peter, wrong bus. Not an MCI. But the thought of getting all the air thru the radiator is correct.
JIm |
LABryan (63.197.32.204)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 26, 2004 - 9:59 am: | |
Thanks, guys. Jim is right, getting all the air through the radiator is not the problem on this bus. Looks like I'll need to pull the radiator and have it cleaned. Your suggestions are all appreciated.
Bryan |
madbrit (67.136.98.31)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 26, 2004 - 11:54 am: | |
Ooops, forgot to check back to the beginning. So used to the standard MCI cooling problems..... LOL.
Peter. |
mikekerley (207.230.142.240)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 26, 2004 - 2:46 pm: | |
I'll beat this horse one more time.
Have a 93 CC conversion, same engine and transmission. Traveling through desert (Florida to Colorado and Vegas) this spring I seldom saw temps over 200 while towing Grand Cherokee. Was warned to "keep the radiator clean and clear". I get a fair amount of oil from the fan gear box seal which would clog up the fins if I did not clean them off, on a regular basis. I use the green degeaser and garden hose to rinse on a regular basis. Works for me (until I fix the gear box seal). Previous owner installed a "water cooler" on outside of radiator which will spray fresh water on coils "on command". I have yet to need to use it. |
Jim Ashworth (Jimnh) (172.200.246.155)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 26, 2004 - 5:43 pm: | |
Mike- Don't fix the seal if the gearbox is a Boston Gear model. Replace it with the new Superior box, fill it with synthetic oil and forget it for years.
The likely reason the seal is leaking is that the bearings are loose, check for play. To rebuild that box will cost about $75 less than putting on the new box.
Jim |