Hi Kids,
I'm actually shooting this out there for a friend with an 04 Tahoe. Swapped out the water pump, and installed a shiney new top-shelf fan clutch. Still running hot/overheating when he runs his AC or does the around-town-errands.
What do you reckon I'm missing?
ps....he uses the GREEN antifreeze, NOT the GM orange stuff.
pss ... he's got the 5.something V8

 

Possibly a bad thermostat which would an easy fix. There could also be a partially clogged radiator or even motor block. Back flushing the radiator would could help.

 

Does it overheat on the hiway?

 

Unknown, hes been afraid to take it out on the highway. But lemme ask you this....... When you get that bag-azz type water pump for this particular vehicle, isn't the new thermostat intergrated/included/already in there. I'd hate to think his mechanic buddy had all that disassembled and didn't put a new thermostat in while he was there.

 

That I don't know. As oldchevy pointed out, and highway driving would "explain" partial restriction in the system if it was overheating. Residential driving , meaning alot of stops, could be the issue, however the system should handle that. The fan clutch, is it for air conditioned car? I, again, am asking as the OLD car fan clutch are marked with a T on the clutch for air conditioning. I know you posted it was replaced, and I don't think anything "modern" wouldn't have A/C.

 

One thing to add, is it actually overheating?

 

It IS a vehicle with AC and I got the fan clutch accordingly. And it HAS overheated once...... now he pulls over when it gets too hot to prevent that from happening again.

 

While the thermostat is attached to the pump, it does not come with a new thermostat, and the housing to hold it on the pump.

 

my 03 denali always overheated or maybe I should say the temp would rise really high. I did water pump, therm, radiator etc. never could figure it out. It would get real hot sitting in summer phoenix traffic too.

 

Coolant mixture can also be a factor. I do a minimum of 75% coolant to 25% distilled water.