Overheating while ac is on at a stop or slow speed .

So I got a 05 trd offroad 4.0
Last weekend I was wheeling and it was around 90* outside . I turn on the ac then the temp gauge shot up pretty high . I stopped cranked the heat rolled down the windows and stood outside for 5 minutes . Temp came back down to normal operating temp . Continued the day without using the ac and the truck didn't overheat .
While normal street driving I can use the ac and it doesn't overheat and the ac is cold like it should be .


Things I've checked .
Coolant is full .
Belt is good
No leaks
Ac compressor was replaced when I bought the truck at 40k I now have 100k on it .
Anyone have any ideas . Or things to check ?

 

Check the fan clutch. With that many miles it may be on the weak side to cool at low speeds.

 

Thanks buzz . I'm going to look into that today .

 

Yeah fan clutch or time for water pump and flush?

 

Honestly sounds like fan clutch to me.i just did mine and it makes a world of difference. You can test it by getting the truck up to operating temp and trying to stop the fan with a rolled up newspaper. If you can slow it to a stop, replace it. 122 $ at advanceauto.

 

Thanks jack
I'm putting my money on the fan clutch myself . Ill try the newspaper trick in the morning . Did you need to remove the upper radiator hose to replace the clutch ? I guess I might as well replace my coolant while I'm at it.

 

No, just disconnect the shroud for more wiggle room. It's easy. I'll only drain fluid and replace when I do the timing belt since it will be in pieces then.

 

Ya I tried that earlier in the week . Didn't help . I picked up a fan clutch today. Try to get that in this weekend . Thanks though .