| Author | Message | ||
| Austin Davis (Zimtok)
Registered Member Username: Zimtok Post Number: 65 Registered: 9-2006 Posted From: 216.37.73.226 Rating: N/A |
I have a 4104 (1960) DD 6-71. Should the engine come up to normal operating temp when sitting and at "HIGH" idle? I now have the shutters working, but it never gets up to normal temp (160-180) until I have been on the road (highway speeds) about 20-30 min. If I am running around town the temp drops again. Then when I park and it sits the temp goes back down to almost nothing again. . | ||
| Douglas Wotring (Tekebird)
Registered Member Username: Tekebird Post Number: 55 Registered: 10-2004 Posted From: 69.136.90.146 Rating: N/A |
it should get and stay warm it might be and your gauge is inaccurate | ||
| Jerry Campbell (Jerrync)
Registered Member Username: Jerrync Post Number: 58 Registered: 7-2006 Posted From: 69.132.150.103 Rating: N/A |
It maybe the therostat | ||
| Richard Bowyer (Drivingmisslazy)
Registered Member Username: Drivingmisslazy Post Number: 1803 Registered: 1-2001 Posted From: 75.108.79.170 Rating: N/A |
I do not think it will come up to operating temperature when just operating at high idle. Richard | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 385 Registered: 10-2003 Posted From: 71.58.126.56 Rating: N/A |
mine has never come up to full temp on high idle, unless it is hot out; you need to get it out on the road or run it with the block heater plugged in while idling might help, but probably not by much. | ||
| Jim Wilke (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 109 Registered: 2-2001 Posted From: 69.77.151.82 Rating: |
Hi Austin, On the stock 4104 there are two thermostats in the housing up behind the valve cover. One is normally closed and opens as the engine warms up. The other does just the opposite. They work in concert to recirculate coolant around the engine while cold, then gradually open to circulate through the radiator as the engine reaches operating temp. There were a number of reasons they did this. One was so that water would circulate whenever the engine was running, another was to provide heat to the coach heater and defroster heater as soon as possible. Still another was to prevent thermal shocks to the engine as "chunks" of cold or hot water would go through the system as a single thermostat opened & closed. The normal thermostat is available from Detroit Diesel, but they don't seem to make the other "reverse" one any more. I was lucky, mine were both there but the regular one was sluggish & I replaced it. You should isolate the engine by the heater valves, drain about 5-10 gallons of coolant in a couple of buckets, remove the thermostat cover housing & see if both of those thermostats are there. If they are, remove them & test them according to the procedure in the 4104 book (you rig up a pot of antifreeze/water mixture, an accurate thermometer like a candy thermometer or if you have access, a multimeter with thermo option. You heat this pot on a hot plate or similar while observing the temps at which the one starts opening and the other starts closing. I had to get a buddy to keep the coolant mixed with a little "propeller" type paint mixer in an electric drill as I couldn't get decent readings otherwise. Sounds like a pain but that's how you are sure the two stats work in concert. In addition, you don't want to casually discard $70. thermostats. My guess is that you will either have one or more incorrect thermostats or one will be stuck. I'd bet the rare one will be missing. If so maybe one of these guys will have one or there are also some old bus junkyards that can help. By the way, I think mine (no shutters) would take about 35 minutes to come up to about 130 indicated and it only comes to 180 after about 10 minutes on the road. Once there it is steady as a rock within about 5 degrees even pulling a 7% grade towing an Explorer. Jim-Bob | ||
| Bob greenwood (Bob_greenwood)
Registered Member Username: Bob_greenwood Post Number: 563 Registered: 7-2006 Posted From: 64.136.49.228 Rating: N/A |
It really seems like you are working on a problem that isn't a problem.The dd diesel is not an engine to play with in the driveway.It was made to get out on the hiway & go somewhere after you get it up to 180 on the highway, & then enter town & it starts cooling off,check your shutters & they should be closeing,& at idle ,when it gets back down to 100 ,they should be shut,kinda sounds like the thingy that controls the shutters isn't regulateing temp,...also, might try one of those laser temp guages & point it at the thermostat houseing & see what actual temp is compared to what your guage shows. (Message edited by bob greenwood on January 18, 2007) | ||
| Austin Davis (Zimtok)
Registered Member Username: Zimtok Post Number: 66 Registered: 9-2006 Posted From: 216.37.73.226 Rating: N/A |
I don't believe the Temp gauge is incorrect by very much if any. when on the road the temp reads at just above 180 and then settles down to just below 180 presumably after the shutters have opened. I realize that the engine may not come up to full temp sitting in my driveway but it never comes up off of the bottom (100 deg mark). And if I run the heater and defroster while on the highway the temp will slowly drop till it gets to around 140-150. This is with the outside temp at around 30deg. I can't say what it will do in warmer temps because I just got the shutters to operate in the last couple weeks. (I made my own As time and weather permits I will get around to checking the thermostats. For now I will keep an eye on it and get a feel for how it operates. | ||
| Douglas Wotring (Tekebird)
Registered Member Username: Tekebird Post Number: 57 Registered: 10-2004 Posted From: 71.230.19.74 Rating: N/A |
even without shutters it should not drop to 150 while driving after getting to op temp of 180. t stat is my suspect. | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 386 Registered: 10-2003 Posted From: 71.58.126.56 Rating: N/A |
If you haven't verified that it actually has the thermostats in it, and was missing the shutters when you got the coach, someone may have removed them due to an overheating problem in hot weather. Did you say that " you made your own?"...shutters? if you did, maybe they don't do the job like the originals | ||
| Richard Bowyer (Drivingmisslazy)
Registered Member Username: Drivingmisslazy Post Number: 1804 Registered: 1-2001 Posted From: 75.108.79.170 Rating: N/A |
In 30 degree weather you need to throw a throw rug up against the radiator while the engine is running. Leave it there until the temps start climbing above 190. Richard | ||
| Douglas Wotring (Tekebird)
Registered Member Username: Tekebird Post Number: 58 Registered: 10-2004 Posted From: 69.136.90.146 Rating: N/A |
Shouldn't have to through a rug over the radiator.....he has shutters. I get mine up to temp in 10 minutes of city driving after airing up when it's well below freezing | ||
| John Zabrocki (John_z)
Registered Member Username: John_z Post Number: 28 Registered: 9-2006 Posted From: 64.61.224.219 Rating: N/A |
Hi Austin, I would be very interested in learning how you made your own shutter system. I am missing the shutters on my 4104, and am having the same kind of symptoms with trying to get my bus to heat up on the road also. If you have any pictures posted or any info you care to share, could you please let me know. Thanks. John Z | ||
| Douglas Wotring (Tekebird)
Registered Member Username: Tekebird Post Number: 60 Registered: 10-2004 Posted From: 69.136.90.146 Rating: N/A |
I have some brand new shutters for a Gm Old Look Transit....I think they are a bit smaller than the 04's but would certainly restric air flow. | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 288 Registered: 11-2005 Posted From: 63.97.117.31 Rating: N/A |
Austin, This is normal. My 4104 w/shutters does the same thing. This engine just won't warm up in cool weather until it is driven awhile. Wait until warmer weather and do some more checking then, but I don't think you have a problem. This is a cold running engine. | ||
| Douglas Wotring (Tekebird)
Registered Member Username: Tekebird Post Number: 61 Registered: 10-2004 Posted From: 69.136.90.146 Rating: N/A |
once it is warm it should cool down just because you are driving around town....he does have a problem | ||
| John Zabrocki (John_z)
Registered Member Username: John_z Post Number: 30 Registered: 9-2006 Posted From: 64.61.224.219 Rating: N/A |
One reason i suspect that my main engine stat is bad is just a few minutes after starting, i can put my hand on the return line from the stat housing to the radiator, and feel it is warm, but the temp gauge has not even moved yet. I have had the stat housing off, and this stat is capable of completely shutting off the water, there is not week hole or bypass built into it. With the engine this cold, all of that warm water should be going out the bypass stat,, not to the radiator. Weird thing is that the main stat was closed when i removed the housing. I could not remove it to test it. I think it is opening way too early. Does any of this make any sense to the older heads here? | ||
| Austin Davis (Zimtok)
Registered Member Username: Zimtok Post Number: 67 Registered: 9-2006 Posted From: 216.37.73.226 Rating: N/A |
John, I was lucky in that the shutters themselves were intact. What I "built" and installed was the actuator that opens and closes them.  I was also lucky that the Shutter stat, and air filter were also intact and operational. (although I will probably rebuild the filter) I am suspecting that the thermostat/s are not working or have been removed. (I also feel the heat on the top radiator hose long before the temp raises) I have found that it was common practice to remove thermostats in hotter weather months to prevent overheating. (Even I had done it on my 65 GTO before I installed an aluminum radiator and better pump.) . (Message edited by zimtok on January 19, 2007) (Message edited by zimtok on January 19, 2007) | ||
| RJ Long (Rjlong)
Registered Member Username: Rjlong Post Number: 1164 Registered: 12-2000 Posted From: 71.195.127.101 Rating: N/A |
Austin - Might want to invest in one of those new, inexpensive infrared temp guns to actually measure the temps. I got one at Harbor Freight on sale for less than 30 bucks. Handy for measuring other temps too - like tires. Be careful with the t-stat housings, don't want to break one/both! FWIW & HTH. . .  | ||
| John Zabrocki (John_z)
Registered Member Username: John_z Post Number: 31 Registered: 9-2006 Posted From: 64.61.224.213 Rating: N/A |
Austin, nice job on getting your shutters to work. That puts you quite a ways ahead of my progress. I think if i can get a working main stat, i can partially block off the radiator, to get by for the short amount of time of the year that it will be an issue. RJ, how well do those temp guns work? How could you use one to chk on the actual water temp, in order to see how accurate the dash gauge is? I have seen them mentioned before, but have never seen one in person. I could not get the main stat out of the housing, so i just put it all back together. I was not able to get the bypass stat housing cover to even come off! I had earlier been warned about the scarcity of the water outlet manifold, so again, i just put the nuts back on and left it. I don't even know if the bypass stat is in there. | ||
| Douglas Wotring (Tekebird)
Registered Member Username: Tekebird Post Number: 63 Registered: 10-2004 Posted From: 69.136.90.146 Rating: N/A |
I got two little ones key Fob size for 6.00 each at Harbor Freiggth....work great and are quite accurate from my testing.....one always reads 1 degree hotter than the other but very close to normal thermometer readings as well as My mechanics Snap On IR Gun | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 388 Registered: 10-2003 Posted From: 71.58.126.56 Rating: N/A |
Austin: BTW... does your coach still have the complete fan shroud? Your actuator looks pretty nice. | ||
| Austin Davis (Zimtok)
Registered Member Username: Zimtok Post Number: 69 Registered: 9-2006 Posted From: 216.37.73.226 Rating: N/A |
Fan shroud is there but there seems to be a piece missing. The missing piece is at the rear of the bus. It looks like a piece that was removable for access to the fan area. . | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 291 Registered: 11-2005 Posted From: 63.97.117.18 Rating: N/A |
Austin, My 4104 has the same fan shroud piece missing? I would like to know why for sure but access to something by bus company mechanics is a very good guess. Mine was owned by Trailways first. | ||
| Austin Davis (Zimtok)
Registered Member Username: Zimtok Post Number: 73 Registered: 9-2006 Posted From: 216.37.73.226 Rating: N/A |
If I had to guess as to why this portion of the shroud would be removed other than for access to something would be to change the air flow across the radiator and fan. Think how having this off would change the air flow. It would allow the fan to pull some air in from the side of the radiator instead of through it. This may help in the cold weather to aid in keeping the temp up. Also it may help in allowing air to be pulled in when the shutters are closed. I don't know it could have just been removed and never put back on by a mechanic. Much the same way the pans under the engine were removed. My bus was owned by Great Southern Coaches. . | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 390 Registered: 10-2003 Posted From: 71.58.126.56 Rating: N/A |
It is missing because, with it missing, you can remove fan blade and or shroud without removing radiator; still a tight fit. you should make a piece to replace the missing piece as the hole causes a loss of efficiency. Be sure to make it as heavy of material as the original shroud, and use at least four bolts to secure it with self locking nuts, as you have vibration and a lot of suction working on it. Oh.. make sure the bolts clear the fan blade by at least an inch, or they will make their own clearance. BTW, check your fan blade for any looseness, as it likes to go through the radiator if it's mounting fails. | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 294 Registered: 11-2005 Posted From: 63.97.117.22 Rating: N/A |
I haven't replaced my missing shroud because it allows me to easily check the fan bearings, a common failure on 671s, and it doesn't seem to affect the engine temps at all. Having it in place would only help if the engine ran hot, definitely not a problem with this setup. Shrouds on any engines are there to pull more air through the radiators. Some engines need them and some don't. This one doesn't. If it pulls any air from the back side of the radiator the air will not go through the radiator so it has no cooling effect one way or the other. |
