New issue where my 22re temps start to climb when I am at a stop. Radiator is around a year old and looks fine. No leaks that I can find. Installed a dual stage thermostat 2 years ago. New water pump around a year ago.

When moving its nice and cool, gauge is around the middle or less but when I stop it steadily creeps up. Seems to stop moving up if I put it in park. Fan is running, I do have a winch on the front which I am not sure if preventing airflow but I sort of doubt it.

Anyone seen this? I was thinking maybe fan clutch but its spinning fine.

 

​​​​​Mine used to overheat sitting in traffic or pulling up long steep hills. Does your gauge ever climb near the red on the hills? The problem I had was a small leak in the rad that only showed itself on an overnight pressure test. This could be lots of things, but here's some ideas:

Are you missing the fan shroud? That can cause the fan to cool inefficiently, which would cause more issues at idle than while moving. What throws that theory off is when you say it's ok in park. You have an auto then, I'm guessing.

Check the coolant temp sensor with an ohm-meter.

When a fan clutch goes bad it still always spins, but with the wrong amount of resistance.

A coolant passage could be blocked.

This is a long shot, but when was the last time you changed atf? If the stuff ever overheats it loses some cooling ability.

 

Fan shroud is good. I can check the temp sensor.

No high temps on hills. It rises pretty slowly. I have to be stopped for a couple minutes before I can see the temp climbing.

ATF was actually changed 6 months ago after I changed out the flange on my transfer case. Is there a good way to check the fan clutch?

 

Anytime I have had a temp to rise while sitting and then the temp goes down is due to a dirty radiator. I know you said it looks good but did gunk get out of the engine block and clog this radiator? What was the reason for replacing the last one?

 

The last one was just old and cracked and leaked like a sieve. I am not saying it not clogged, very well could be. It gets plenty dirty on a regulr basis. How would one check if it is clogged?

 

i'd look for junk in the fins, especially in the front side of the radiator.

when my truck overheated like that, it was a bad fan clutch.

i never did figure out how to reliably test the part, just replaced it.

 

Infrared Heat gun is your friend for checking blocked radiators

I don`t think I have any with fan shrouds they were long gone before I adopted the vehicles

Fan Clutch
When the engine is at operating temperature shut off the fan clutch should be harder to turn by hand then with a cold engine if it spins easy time for a new one

Then it might be a gauge problem

Your transmission is still sending fluid to the cooler in park so putting it in park does not change the cooling load

 

Ordered a new fan clutch. I'll see if thats the issue.