Help! My 84 pick up 4wd has been running hot, but not overheating. I took it in for a routine oil change, they said the water pump was leaking so they replaced it. When I got it back it was really noisy so they replaced a pulley. Then it started running hot, at about 3/4 on the gage. It normally runs at 1/2. The shop said it was the fan clutch so they replaced that, but it made no difference. Everything was working fine before they replaced the water pump. Any suggestions as to what the problem is would be greatly appreciated.

 

If the pulley circumference is a bit larger than stock, it'll turn your pump slower which will cycle the coolant accordingly. Perhaps the pulley they installed is wrong for your application. It could always be the radiator. I See you refer to the desert in your identity. If you drive there often, you should switch to the V6 radiator anyway. It's a three row core and bolts directly up to your rad support...

Another thing to strike from the list of possibilities is a blown head gasket. There are other symptoms that accompany that ailment though.

 

Maybe the shop did not flush it properly and there is a bubble in the system. Is your temperature consistant at 3/4 or does it fluctuate?

 

All that is left to replace is the thermostat (which should have been the first component they replaced), radiator cap, and the radiator itself. Start with the cheap and easiest parts first which would be the thermostat and radiator cap.

Might as well get the 2-stage thermostat for the following reasons:

http://www.4crawler.com/4x4/CheapTri...tml#Thermostat