Long story short, I have replaced the head gasket, thermostat, radiator, as well as all new liquids.

After replacing the radiator (last thing that was done), it was still running hot. Had a friend and his dad help me out and they took 2 days bleeding the coolant system and freeing it of air. It worked for some time.

So since then (2 days ago), it's been running 195 or cooler. Thought that was the end of it. Today it started going higher again. Hit 230 once, hung out at 215, but it's pretty much all over the place. It'll go back down to cool for a few seconds then climb back up again.

We were sure that the air was out of the system. Could there be more air? Could I have an air leak somewhere? Maybe Coolant reservoir cap?

We never flushed out the heater core. Speaking to a local enthusiast briefly, he mentioned that i should do that and there's a pretty big chance that there's blockage somewhere in there. And, possibly, the new thermostat would already be bad.

Any suggestions???? I'd rather kick beat the @!#$ out of it and burn it to the ground at this point.


-Markus
2002 Yellow Cavalier LS Sport *SOLD*
2000 White Cavalier Sedan
Check it out! --> Flickr

Did you have the head re-surfaced & pressure checked? If you suspect the heater core, you can run a "U" shaped hose to bypass it to see if this has any effect.

I tried to take a JY head & use it without resurfacing & I ended up re-doing it. I hope that helps.

just curious did you put the head gasket on correctly? dont know if it can be flip flopped, i would ask about cooling fans but they dont kick on till 232

Head was resurfaced, yes. No, I did not put it on backwards. lol

Could it possibly be the water pump? Maybe it's not working like it should from whatever corrosion might be in there?


-Markus
2002 Yellow Cavalier LS Sport *SOLD*
2000 White Cavalier Sedan
Check it out! --> Flickr

I know that it can be hard to get all the air out of the cooling system. Thermostat was replaced so that shouldn't be it.

No oil in the coolant or vice versa? Stupid Q, you made sure the cooling fan is coming on all the time (I mean when it should come on)? Sometimes the motor will get a bad spot & depending on where it happens to land when it stops, it won't kick on again when its supposed to.

Your car isn't overheating, it just has a fever, just give it some Tylenol and let it rest.

What brand tstat did you use...?

Heater core would be a suspect. I would run a U adapter see if that helps.

good Luck.

did you get the head shaved? did you check the valve area?

Here is a really stupid question, buuuuutttttt, have you ever replaced the pressure cap on the surge tank??? I ask because if its sticking it will cause the car to overheat and not build up the right pressure, but build up wayy to much, and cause the car to run hot. Try and and go from there. Cheap enough since that is literally the only thing left lol. Also, if your heater core was clogged, it would not cause the engine to run hot at all, it will only cause you to not get heat inside the car. Our cars have a by-pass built into the heater core lines. If the core is blocked, it will just bypass. Not overheat the car. That is not engineered to cool the engine only to supply heat into the passenger compartment. So I really doubt your heater core has anything to do with it. You could have a blockage inside the engine block itself, but those are really hard to find. Either way, post back up and let us know, good luck!!!

def. suspect the heater core....... that was my problem on my 2200 and it kicked my a** for about a month it would blow hot but the blockage must have been on the outlet side.... try to bypass it like rich says with a u hose or a bypass hose of some sort. I unclogged mine by pushing shop air pressure 100 psi on the outlet side with both hoses disconnected from the engine side till the clog broke free but you can blow up your heater core that way too if its weak.