Hello I have seen alot of threads about the Auto tranny i have a 91 4runner with an auto that is doing the same things shifting out of O/D. The temp will reach right before midway point on the gauge while riding around town and the O/D works great. The problem is when I get up to traveling speed around 55mph or faster the temp will drop and then it will shift out of O/D. Second where is the temp sending units on motor and tranny and how would I fix this sudden temp drop?

 

See this link and scroll down for a picture of the location of the electronic controls.

http://personal.utulsa.edu/~nathan-b...34electron.pdf


Does the engine temp rise normally? Are you sure there is a properly functioning thermostat installed?

Mike in AR

 

My truck is doing the same thing. After watching the temp gauge all the time I found that when the engine temp went down the truck would shift out of overdrive. I'm going to replace the thermastat we I get a chance, and see if this will take care of my problem. Have you noticed it will only do it when the outside temp is below 30 to 40 degrees. That is what I've noticed and maybe a cover for the grill could be a solution for winter driving if a thermastat of temp sensor does not fix the problem. Either way I do not experience the problem when the outside temp is above 40.
If you get to changing out the thermastat with in the next week post the outcome as to if your problem went away. As far as the location for the sensor search a little more some one put a great pic on about a week or so ago.

 

I have already changed the Thermostat that did not solve the problem.On the other hand I live in Houston and I rarely ever see 40 degrees this will hapen when the temp is below 75.

 

Well that definetly makes it more the sensor then. Sorry I didn't know where you were from. There is also a sensor on the tranny, Maybe two of them. I know those are over $100 a peice so if the one on the motor is fairly cheap I would start there. Good luck on the repair.

 

Thanks for the help, Other than that the old 4 runner runs great when its in o/d I get around 15-17 when its out of O/D 9-12 mpg. Thanks for all your help.

 

Hey DaShry1,

Did you fix your O/D problem????