car runs hot after tranny rebuild
- Thread starter gngeorge
- Start date
- Joined
- May 28, 2001
Lock up not working....
that. or slipping clutches already?
- Joined
- May 26, 2001
......or maybe a "road test" that pushed a head gasket???????
Worth checking if nothing else.
George as me being the person who built the transmission Id say its hard to pin point why a rebuild would cause it to run hotter , if in fact the 2 are even remotely related.We know the lock up is working and the trans shifts firm and fast and there is no slippage at all.I held the upper and lower radiator hoses with the car running and there is definately a temperature difference between the hot coolant entering the radiator and the coolant exiting.There is a front mount intercooler on the car which always is an obstacle in the way of incoming air to compliment the heat exchange accomplished at the radiator.I suggest replacing the ,coolant temperature switch that grounds the fan relay and the thermostat as the beginning steps in diagnosing the problem as well as checking the connections at the fan relays and maybe replacing them as well if there is any melted plastic or signs of loose connections at the contact points.Using oem quality parts this should cost you less than 100 dollars andyou can do it in a half hour or less with the engine cooled off.
- Joined
- May 26, 2001
chris,I am only looking for different ideas and opinions from other people on this site,besides I only thought you were on the trans questions section of this site!
Chris has been on this board a long while, and is a well respected vendor. He know LOTS more about turbo Buicks than just transmissions, and you should have asked him first. [Which you could have done with a local phone call?]
Being local, and already knowing your car, qualifies him better than the board posting to help solve your problem. Just him answering here shows that he is a stand-up person.
I come thru here from time to time George.It would be interesting to hear others input though.The first thing that comes to mind would have been the lock up but we already know thats working.The excessive engine rpm at highway speeds unlocked could cause the engine to get hotter and this could be a culprit if the the lock up was not working,but we already know it is functioning.If we were to suspect elevated transmission temperature raising engine coolant temperature during heat exchange it should be viewed as follows.Even if the lockup wasnt functioning it would be hard to find that as a cause cruising on the highway at 60 mphour for 5 , 10 or 20 minutes which is the extent of the testing we did looking it over.The added heat in the transmission fluid transferred to the engine coolant during heat exchange would have to be at a very high temperature to raise the coolant temperature 20 degrees.For this to be at work it would be accompanied by a great increase in engine rpm during cruise.Another thing to check is the temperature sender itself that feeds info to the gage.Perhaps the gage is reading improperly.With the engine off and the key on place the sensor(unscrewed from the intake of course)into a small pot of boiling water and notice what the gage reads.It may be wise to boil the water with map gas so it doesnt have time to cool.Just extend the plug for the sensor so it can reach over the fender into the pot.Also the prescense of air in the coolant system can cause inaccurate temp gage readings although it would need a large amount of air for this to be happening.Maybe something is here Im not seeing ,but I dont see what at this point.Nick,is there anything I could be leaving out?
I assume a new convertor was used along with the new trans build. How much room between the flex plate and the converter. I am assuming that you put the trans in and not chris(you did not include this info). If you do not remember having to pull the converter forward to bolt it to flex plate, then check your crankshaft end play. Just want to make sure of two things, the converter was seated into trans all the way and that the converter was not to big (ie ballooned etc).
Another suggestion is to get your hands on a digital thermometer. After driving around and getting things up to operating temp, stop the car. Open the hood and see what the temp is for coolant hoses and for tranny lines. see if you can tell where the extra heat is acoming from. This may tell you if it is the tranny or the engine.
Were any other changes made to the car at all?
How bad did the last trans destruct? Did you flush the tranny cooler or have it replaced?
Another suggestion is to get your hands on a digital thermometer. After driving around and getting things up to operating temp, stop the car. Open the hood and see what the temp is for coolant hoses and for tranny lines. see if you can tell where the extra heat is acoming from. This may tell you if it is the tranny or the engine.
Were any other changes made to the car at all?
How bad did the last trans destruct? Did you flush the tranny cooler or have it replaced?
yes external cooler and a 5 row radiator
changed the stat(160)flushed the coolant,seems to be flowing fine.
Chris at CK did the install also,he flushed the trans cooler and lines.Chris said the converter was fine,if it wasn't I had no problem with Chris putting in a new one.The trans before the rebuild was over revving between 1-2 shifts at WOT.I'm sure Chris did a fine job on my trans.I'm just trying to get different ideas on why the car is running hot.Chris and I spoke about a month ago and if I keep the car Chris will get her running good again.Like Nick said, Chris knows a lot about buicks than just trannys.
