I'm having an issue with my tranny not wanting to shift to 3rd after the engine gets warmed up. It shifts fine until it gets warm. Now when it does this and i turn the car off and let it cool down for a bit, then the tranny shifts fine until it gets warm again. Now I plan on getting a tranny cooler instead of running the cooling lines through the radiator. Right now my cooling lines are pretty close to my headers, would the tranny fluid getting hot cause this to happen? Hopefully you guys have a solution for me. Thanks

 

If you think this could be part of the problem, I'd say give it a try. I'd want a transmission cooler on there anyway. I think the consensus is that you should run the lines through the radiator, then through the trans cooler.
Have you dropped the pan, checked it out, changed the fluid & filter?
Park it a little closer to the computer and you might get a better diagnosis.

 

Yeah we changed the filter before we put the trans in after rebuilding the motor. The car did this when I first bought it, but I thought maybe it had something to do with the motor not running right but the motor is good now and I'm still having the same problem.

 

Does anybody have any ideas on what would cause this so i can try and figure out how to fix the problem?

 

I think your on the right track on the routing of cooling lines. My theory is that the aluminium valves in the valve body are heating up and expanding against the iron valve body, causing them to stick.

I also suggest running through the radiator first, then a trans cooler, as ijasond suggested. The tranny needs a little heat in the fluid, especialy on cool days.

Also, make sure the is no obstructions in the cooling circuit like kinked lines. If you take the pan off make sure the valve body bolts are tightened to spec.

Does reverse work when the car is warmed up? do you know the converter stall speed?

jason

 

Reverse does work, it only has issues shifting to 3rd. I'm not sure about the conveter speed.