Overheating Help (I'm stumped)
-Yes I've spent a lot of time doing a search
-New radiator cap didn't help
-New thermostat didn't help
-Yes the system was bleed of air after it was re-filled
-Yes my fans are coming on
-No leaks anywhere besides the overflow tank
-Coolant is circulating in radiator
-No oil was mixed in with coolant
-No coolant was in my oil when changed 2 weeks ago
-Exhaust doesn't smell like burning coolant
-No debris is blocking the radiator
I'd pull the rad out and inspect it closer, service it. Flush it thoroughly with a hose. Are the fins all mashed up can it breath?
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Let me know if you think the water pump could be failing. Whatever the problem is, it's progressively getting worse. I went from overheating about every two days, to once per day, to now having to pull over 3 times in a 15 mile drive from work. All of this has happened over the last 5 days btw. I'm heading out to eat now (not in my car haha) and am going to flush the radiator and put a new water pump on unless anyone thinks that's not the problem.
-Yes I've spent a lot of time doing a search
-New radiator cap didn't help
-New thermostat didn't help
-Yes the system was bleed of air after it was re-filled
-Yes my fans are coming on
-No leaks anywhere besides the overflow tank
-Coolant is circulating in radiator
-No oil was mixed in with coolant
-No coolant was in my oil when changed 2 weeks ago
-Exhaust doesn't smell like burning coolant
-No debris is blocking the radiator
The only way the coolant will start to boil over is "air is getting into the cooling system", period. Your temp can go all the way into the red on the gauge, as long as the system is tight with NO air, it won't boil over.
Last edited by needadvice; May 9, 2008 at 02:14 PM.
Also, don't waste your time removing the radiator to flush it. If you open the drain on the bottom and it drains normally, the radiator is not clogged.
I think its the head gasket though. Get a leakdown check done. Sometimes if its bad enough you can rev the engine at the TB while looking into the radiator (with the rad cap off) and bubbles will come to the surface while revving, sometimes.
If the gasket(s) is blown the piston on the UP stroke will push the air into the coolant system. On the DOWN stroke it will suck it out of the coolant system into the cylinder and out the exhaust. BUT ONLY SOMETIMES if the blown part is big enough. Rev the engine pretty good and see if coolant comes out of the exhaust pipes. Or, were you losing coolant over time before the overheating got really bad, like a few months ago.
Is it losing fluid at all or just getting hot?
Is it losing fluid at all or just getting hot?
Air in the coolant is the killer. It drops the boiling point way down.
I bet when this guys coolant is boiling over his temp gauge is nowhere near the red zone.
Also, what did he do to rule out a blown gasket? Checking for coolant in the oil or coming out the exhaust is not the tell tale sign of a blown gasket. It can be a very small hole in the gasket that is getting a lot of air pushed through by the upstroke piston, but only sucking in a tiny bit of coolant on the downstroke, not enough to detect. I've seen this on more than one car.
If the entire cooing system checks out, what else can it possibly be. Boiling coolant before the temp goes into the red means air is in there.
He needs to do a leakdown check.
I just tore it down and found a blown head gasket. Not bad but bad enough.
Also check the trans temps if it's an automatic. I had a LSX work truck that would boil over. Come to find out it was a trans problem, it was boiling around the trans cooler in the side tank.
I just tore it down and found a blown head gasket. Not bad but bad enough.

