Hey guys I got a brand new built 4l60e I swapped into my stick shift c5 vette and I can't figure out why its overheating. I have two trans coolers under the headlights so I know they are getting direct air because they are where the brake ducts use to be and I also have a fan on each of them. I made sure there was enough fluid in it by putting it on jack stands and let it idle at correct operating temperature and it was fine there was fluid coming out when I pulled the plug. Also I know the fluid is getting to the coolers because I can touch the coolers with my hand through the front bumper and I can feel them get hot. I drive for maybe 10 minutes and it'll be at 200 and thats on the highway at night. I have a stand alone trans controller that came with a base tune and I am gonna mess with it because im thinking maybe the converter isn't locking? Anybody got any experience with transmissions? Trans has seen 230 but was shut down right after and I checked the fluid and it didn't smell burnt and when I do drive around it shifts perfect it doesn't slip or anything. Would like to see what people with experience think about this issue.

 

What trans cooler(s) are you running?

Where are you measuring temp? At the controller?

Definitely sounds like your converter isnt locking.

Mine creates a lot of temp when unlocked and cruising. I have a separate gauge on the cooling line out to the cooler. When unlocked, it always shows hotter than the tranny temp on the DIC (factory PCM controlled). However, I have still never overheated with my B&M 70297. When locked and cruising in 100+ temps, I see about 180 Deg F on the DIC.

 

How can one test to see if the converter is not locking up correctly?

 

You should be able to FEEL when the Converter Locks.
It's almost like you hit another gear.. RPMS drop.
It should do it in 3rd and 4th gear under light load and throttle position
The "slippage" totally goes away when in lock up mode

 

Like foggy said, it won't slip anymore. When cruising at 60+, slightly push in the throttle to accelerate. Do the RPMs go up or stay the same?

 

foggy,

Guess I just don't know what it should feel like.

Other members have said that "if your converter is not locking at highway speeds you will get a P1280 code which is "transmission slipping".

I have no P1280 code and I have checked my codes tons of times since this began

Thanks,

Jim

 

I don't think it would always throw a code.. Depends on what is actually the problem.
Maybe you can find a mechanic to drive it and he should know what/when lock up
occurs.

 

It has been in a local performance shop for over two weeks working on trouble shooting several persistent EBCM relater codes. Ended up getting the EBCM replaced.....long story ;^(
I also had the trans temp issue on the to check/fix sheet. I also left printed details about the several live drive temp tests that I posted on CF. I talked directly with the tech that tested for the overheating. He drove my 03 trying to get the trans to show the temps I recorded for over two hours in 90-100 degree days. He said he drove several hills as well as city streets and couldn't get a temp over 198. He checked the trans fluid level, it was fine and said the fluid looked clean, was not darker in color, had no off smell. So he did not know what else to do at this point. I forgot to mention the possible converter not locking, but I will call and add this tomorrow.

Thanks for all the info and suggestions

Jim

 

I think this is a converter issue then because I don't feel anything once I get into 4th gear and y'all are saying it should feel like I go into another gear. This is my first stalled auto so I'm starting to figure out all the little tricks to make it happy. Ill use my controller and see what it allows me to do with the converter. The controller has a temp sensor and I would of thought the two trans coolers with fans would be sufficient but this seems to be a whole different issue.

 

When mine locks up at ~47 mph and light to moderate throttle, you know it. It jerks hard, like another shift.