Gonzo1

I have a 02 Transam that is blowing coolant out of the overflow tube. Has alot of pressure for some reason. Already replaced the thermostat, radiator cap and new waterpump is going on this week. My question is if the waterpump doesn't fix the problem could it be a blown head gasket? And if so what are the signs of a blown head gasket? There are no visible signs of coolant in the oil nor is there signs of a leak around the heads. Also if that is what it is do I just put new head gaskets on and be done with it or what else is involved? Thanks in advance!

west1055

Sounds liek the gasket is blown. Could be a busted head too. I assume it ran hot, if so how warm did it get? Check for steamy exhaust and more water than usual coming out the exhaust. The pressure you describe tell me compression is getting into the cooling system and that normally comes with a blown gasket. Basically just replace the gaskets but check the head for cracks/warpage and block too since it is aluminum.

Slowhawk

iTrader: (12)

Is the car stock?If so warrenty it..

It sounds like a Head gasket.Just open the rad. cap when it's running.You'll see air bubbles if it's blown.

strokedls1

iTrader: (1)

Sounds like a head gasket to me. I have seen a few that are small leaks that pressurize the coolant at higher rpm and blow out the over flow. A pump won't do that.

crainholio

iTrader: (2)

You should be able to narrow down which cylinder bank it is by looking at your LTFTs, or pulling the front O2 sensors. Damaged side will run low LTFT numbers and have a white powdery coating on the O2 sensor. Coolant poisons the sensor, causing it to read high (rich) and forcing the PCM to pull out fuel (lower LTFT).

From there, you can remove spark plugs and look for the really clean one. The water in the coolant removes carbon very effectively.