hey guys i recently bought a used motor from a junk yard and the motor runs cool on the freeway but it over heats while idling , i just put a new radiator in when i put the motor in , it has a new water pump ?

 

Sounds like the fan clutch if it is doing it at idle...get a napa one if you can.

 

Fan clutch as Martlor13 says and a new thermostat while you're at it. My 95 had a slight overheating at idle when I first got it and the fan clutch and t-stat cured it nicely.

 

i got a fan clutch from oreilys and it still over heats . it was in the red box but it didnt hit 260

 

i put a fan clutch from oreilys and it still is over heating it goes to the red box ? im thinking maybe a cracked head ?

 

Do you have the shroud on your clutch fan? My car seems to have same symptoms and i am missing mine. I'm getting one tomorrow.

 

Cracked head would be either water in the oil or Water blowing out of the radiator, I would think. Only overheating at Idle is probably poor circulation (Bad pump or crud in the engine). Could be the fan clutch also.

 

260 is really hot.

Just a bad fan clutch alone (unless it's completely failed) is not enough to run that hot.

First step is to verify the temp with an IR gun - they're relatively inexpensive and a useful tool to have in your toolbox.

Assuming it's legitimately running too hot, I would immediately get an oil analysis from Blackstone labs on the engine. In the meanwhile I would pull the water pump and t-stat off and flush the heck out of the engine. Make sure the pump is good and put a new t-stat in it.

Good luck and keep us posted!

 

​​​​​​​The shroud is important, but 50 degrees over spec is well beyond a missing shroud.

 

radiator pressure tester.

 

be sure to run a 195* thermostat any lower and it will overheat because the water will not get to stay in the radiator long enuff to cool

 

My xj was running about 30 degrees hot and it was fixed by Just replacing the shroud.