i've been having heating problems for several months now. i recently had the water pump replaced(leaking) and my mechanic told me the clutch fan was shot. after replacing that myself (and the old one was broke) i am still having problems. my motor heats up normal but will continue past optimum level and spike up to around 220 to 240, but not red line. once it hits a certain point it will come back down and not give me any issues. i am not terribly concerned since it runs hot for only a few minutes but id still like to know whats going on. any ideas?

 

It could just be the thermostat with should be about $10-30 not 100% sure on the price but if it is sticking it will cause what you are describing.

 

thank you thats what i've been thinking since there really isnt much left.

 

When it would come bak down, would it come down gradually or would it basically drop bak down quickly? Mines doin this and my gauge will b at 210 and if i turn the heat on, after a minute or so it will DROP bak to normal temp....its not a gradual or slow decline its more of a free fall.

 

If it goes up to crazy temps & then drops down I'd say the thermostat is the culprit/culprick.
If it didn't drop I'd still say that &/or a air bubble in the system.
Possibly a good flush is in order & an old school way to remove air is to drive on a ramp or lift the PS front, remove the rad cap & run it to regular engine temp & rev it to 1200 or so till it burps in 30 second intervals. You'll see this by the coolant level going down & may even hear it. Drop it down, top it up & happy cooling (hopefully)

It's a '94, back flush the cooling system for sure. I'd make sure as much as I could there is no gunk in there.
That goes for both of you Mel incl.
Get the cooling system cleaning kit or w/e they call it & do it. Then proceed to fill, burp & run it. If it still overheats then replace the thermostat. They're only $10 or so.

 

I agree with the stat.. I would flush the system and clean the fins on the rad. It might help. IT can always be the stat sticking too.

Id flush the heater core also .. It might be possible thats plugged too.

 

Heater core? Is there a seperate procedure to flush that?
Back flushing the system should remove a lot of the gunk that's in the entire system.
I suppose you could hook up lines just to the heater core & power flush (garden hose) that out.

I wonder what Sea Foam would be like in a bad DexCool system? Adding that & cleansing the system?
In a flushing screnerio not too bad to clean things, but don't run it for any amount of time though.

 

You can do it separately by disconnecting both hoses on the firewall and back flushing it.

I say the pressure from the hose would clean it out real well.

 

Yeah that's what I thought, just haven't heard of a heater core flush before.

 

I had a full size Chevy with a 4.3 that would overheat because the Cat was plugged up.