4l80e temperature climbing T/275deg
 

I just bought a 06 2500hd & the temperature gauges slowly climbs to 275deg, but the trans cooler is not getting warm.

I've checked for kinked lines & I bypass the radiator & it still climbs to 275.
The fluid is still nice & clean.

Could it be the gauge or the filter getting plugged up? I dont know how the pumping system works for the cooler.

Id start with pulling a line off the cooler and start it for a sec and see if its pumping fluid..
Could be the gauge i guess but doing the above would rule out a blocked line :)

If a line would be stopped up or it's not pumping fluid, what would I need to do too fix it?

Id pull the whole line if that happens and see if clogged..

I just pulled feed line to the cooler & it's pumping. Then I pulled the return line to the trans @ the trans & it's pumping fluid all the way around.

Guess I need a temp gun.

Possible bad temp sensor/sending unit?


Thats odd its reading that.

Put a scanner on it to verify the sensor (HPTuners or EFILive).

I should have brought it with me. I tried a brake stall tonight & it's 2200rpm. is that normal for the 80.

Yeah that's about what it should be. Get a heat gun and shoot the pan and see if it's really that hot.

If it's not I'd replace the trans temp sensor and interal wiring harness.

Thanks.. Once I get home I can try my cluster out the race truck lol. I talked with frank he said if I drove 500 plus miles @ 275 the fluid would be black & it probably wouldn't make it 500 miles