Battling heat problem on 4L80E - anyone else?
03-11-2016, 11:21 AM
#11
transbuilderguy (Robert Godfrey) has a post on his FB about an 80e where someone used the wrong rear fitting,causing a heat issue and roasting the trans.
The issue was that they had used an AN type fitting instead of the stock, long snout fitting. This caused fluid to not circulate properly and overheated the transmission.
I would also feel the lines. With temps that high I would think one would be cold to the touch and the other scorching hot.
The issue was that they had used an AN type fitting instead of the stock, long snout fitting. This caused fluid to not circulate properly and overheated the transmission.
I would also feel the lines. With temps that high I would think one would be cold to the touch and the other scorching hot.
03-11-2016, 11:43 AM
#13
Staging Lane
Thread Starter
I did use the stock fittings and I also unthreaded them to make sure that rear one had the long snout on it, which it did.
I am leaning towards a tuning issue at this point. Just not sure how to flush it out via logging/scanning
I am leaning towards a tuning issue at this point. Just not sure how to flush it out via logging/scanning
03-11-2016, 12:47 PM
#16
Staging Lane
Thread Starter
I did not use the engine coolant radiator at all. The cooling loop just goes from trans to 40K and back. The 40K is right behind my intercooler and in front of the AC radiator.
03-14-2016, 09:31 AM
#19
Staging Lane
Thread Starter
In an attempt to rule out the tune as the root cause, I re-installed my factory 26lb/hr injectors and dialed down my boost. I then loaded the factory tune and made some slight adjustments for the Transmission segment (T42 controller from Express VAN with 4L80E trans) and some speedo related stuff. I took it for a ride and the low RPM driving (non-WOT) was definitely a little more responsive and felt less converter slippage but nothing drastic.
Outside temp was 60F and after about 30 mins of driving stop/go I was up to 185F on the trans. Sitting at an idle, it got to 191F. I then took it for a 10 mile 50mph run and temps dropped to 149F. (lockup seems to let things cool fairly quickly)
From there, I climbed a 1/4 mile hill at 2800 RPM steadily. Temps climbed to 169F by the time I reached the top of the hill. (seems like a steep temp climb to me)
I am starting to think the issue is more of an airflow one. Perhaps my cooler being mounted behind the Turbo intercooler is causing a damming effect on the incoming air. My turbo intercooler is not yet plumbed in so the air is not pre-heated, but it is certainly restricting flow to the 40K. My next test is going to be strapping temp sensors on the two trans cooler lines coming out of the transmission. I want to observe the delta temps in that loop. Does it make sense that I may need a fan on the 40K?
Outside temp was 60F and after about 30 mins of driving stop/go I was up to 185F on the trans. Sitting at an idle, it got to 191F. I then took it for a 10 mile 50mph run and temps dropped to 149F. (lockup seems to let things cool fairly quickly)
From there, I climbed a 1/4 mile hill at 2800 RPM steadily. Temps climbed to 169F by the time I reached the top of the hill. (seems like a steep temp climb to me)
I am starting to think the issue is more of an airflow one. Perhaps my cooler being mounted behind the Turbo intercooler is causing a damming effect on the incoming air. My turbo intercooler is not yet plumbed in so the air is not pre-heated, but it is certainly restricting flow to the 40K. My next test is going to be strapping temp sensors on the two trans cooler lines coming out of the transmission. I want to observe the delta temps in that loop. Does it make sense that I may need a fan on the 40K?
03-14-2016, 09:51 AM
#20
I had my 40k cooler literally smashed between the radiator and intercooler and it would only get above 160 or so when hot lapping or really beating on it. I don't think that cooler location is the problem, unless you have other stuff in the way as well.