3.4 transmission overheating

So my trucks tranny is overheating and throwing the torque converter code. But the converter has been replaced. Overhaul kit and solenoids replaced i mean the gears go in good and no slipping but i notice that it over heats when at highway speeds and specifically when letting off the gas. Would a bad tranny cooler cause this? Im getting ready to replace that and its filter i added but if anyone can help me out id appreciate it. The temps go up to 300 and throw the engine light and transmission oil light aswell.

 

Are you absolutely certain the torque converter is locking up? If it isn't, the trans will overheat. From cold, how much driving does it take to get it to overheat?

 

How can i make sure? And ab 20 min when its running highway speeds it bumps up to 240 iv spent 2500 trying to fix the issue and still nothing makes a difference

 

What things can cause a p0741 code? The mechanic is saying hes going to check the solenoids again but all 3 where changed

 

Converter lockup occurs after you get into overdrive (4th gear). When the TC locks up it is like a 5th gear. On mine the engine revs drop another 500 RPMs when the TC locks up.

Google says this code indicates the TC is not locking up. Could be a bad solenoid or it's wiring.

FWIW, 300°F is very bad for the trans fluid. Avoid getting it that hot and make sure the trans fluid gets changed out once that solenoid gets fixed. Even 240° for a sustained period will cause the fluid to start to degrade.

 

Here's some more details on what that P0741 code means.

https://www.carparts.com/blog/p0741-torque-converter-clutch-solenoid-circuit-performance-stuck-off/

 

I would think you would see a noticeable drop in your RPM's. When I'm on the interstate doing 70mph my rpms drop to about 2250, and stay there. What are your RPM's doing when your cruising down the interstate when the Transmission Temps start to rise.

 

Did this start after you added the remote filter? Just a thought but is the filter head plumbed backwards as in outlet of trans to outlet of filter head?

 

Mmm well i havnt really noticed anything with my rpm but maybe i should keep an eye for that. Everything seems good other then it overheats. The shop that rebuilt that tranny is going to check the solenoid again but i mean he said it was a new one and was working. And about the filter im not sure i follow with what your suggesting.

 

N yea i do pull over when its gets to 300 and now its been running 200-230 way too hot for me its never ran that hot always 150-170.

 

It sounded to me like you added an external remote oil filter with the cooler, is that correct?

 

What was the original reason for taking it to the shop. Was it overheating then? Was it throwing that same P0741 code?

 

what he means, if you have an external Transmission filter, do you have the lines connected backwards.