Engine Temperature Transmission Problem

superchicken94

Registered User
Car is 94 SC with automatic transmission. Symptoms are temperature guage rises to 1/2 to 3/4 guage after extended driving. Transmission will then shift down then immediately shift up. It does this with no load change ie, up hill or increased throttle. Sometimes the temperature will climb going downhill, or come back to the thermostat going uphill. Transmission does not get hot, cooling lines can be touched. Car has been doing this for a while just getting worse. Short trips 10 to 20 miles don't seem to initiate the problem. Thermostat is new.
Anybody else have this problem?
 
sounds like you MLPS manual lever position lever on the side of the trans. If it has a orange rubber gasket sticking out from between it, its been replaced before. These are known to go bad on 94-95 4R70W`s. Over heating could be Rad or thermastat.
 
Im on lucky number 13 and eveyone of them got a new radiator. You might still have the original radiator. Best to replace every part of the cooling sytem if you plan on keeping the car for a while. Every time you spike things get a little more out of wack and blown head gaskets is not a fun job. With the trans you know that the fluid gets hotter then normal as the engine over heats. Both my 94`s did this down shift thing but it was not overheating at the time. The cure was the MLPS. Its what tells the cpu what gear your in as this trans is computer controlled. Hope you get it figured out. It just su<ks when you have someone in the car and she races up on you like that. I just hit the gas as to hide the fact that it malfuntioning:rolleyes: Glad you found us and welcome to SCCOA. If it was not for this site and all its help most of these cars would have been sent to the crusher.
 
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I have been a visitor to this site for a long time, I just don't post much. I have had this car for 13 years. It has 102,000 miles. Always garaged original eveything. I plan to keep it for more years. I just flushed the radiator, it was pretty clean. This transmission issue has happened before (60K) and I had it serviced and it quit for about (30K), had it serviced again and now it is acting up worse this time. I suspected other causes as it has only been 12K since service. The heat issue just started and I thought the trans issue might be related. Is there a way to test the MLPS? Do you have to drop fluid to change it? Is there an adjustment?
Thanks for your help.
 
I didnt see any mention of a tranny cooler in the posts? after the MLPS is checked, you might want to consider one. After I installed on in the '95 LX, I had no issues at all.

Matt
 
I read that entire search. Lots of info. Clearly the most common symptoms of a bad mlps are the same as mine. I will change it out soon. Thank you both for the tips.
Larry
 
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