Overheating and don't know why ?

[Bruce L]

My '92XLT is overheating and don't know why. Here are some symtoms/characteristics:
-HOT air out of the heater vents
-radiator cap "pops" when hot (ie. overpressure)
-upper radiator hose hot
-lower radiator hose warm
-no coolant from weeping hole on pump and no pump bearing noises.
-uppper hose surges after squeezing it which indicates good pump

In summary, I think i have a good pump, radiator(new), thermostat. What else? Any ideas or suggestions?

 

[weebo]

are you positive of the "good" thermostat? it's quite possible that it's stuck closed. that's where i've always found my overheating problems....until i purchased a low temp thermostat from performance products...that's solved all of my woes.

randy

 

[-=DaemoN=-]

lift it, put some 35's and that should fix the problem j/k.

Have you checked your fan clutch?

 

[mahieber]

The clutch on your fan might be shot, not turning the fan fast enough to draw cool are in at idle. One way to test would be if the needle goes towards cool as you drive fatser (forcing air through the radiator). Or the thermostat may be gunked up and not opening all the way.

Good Luck

 

[JDraper]

I'd double check that t-stat, and also make sure it's in the proper way. You can check the t-stat by getting a pan of water up above the opening temp of the thermostat and dunking the thermostat in it. If it opens, it's probably ok.

The fan clutch is definitely another possibility.