Originally posted by JEDsContour: Do you have a V6? The 2.5L's are notorious for water pump deterioration. Relatively cheap and easy fix ���?? if nothing else damaged.
Another more ominous possibility is cylinder leakage (exhaust) into the water jacket. This would be very bad news as it would indicate a bad head gasket (at best). Similar result to what you describe: coolant forced out of block under exhaust pressure into the radiator and overflow tank.
A compression test might reveal it.
Try replacing the waterpump first
Ouch, don't scare me!
You think water pump eh? Hmm... Coolant is getting forced back into the tank.
Hmm, I may try that. But there are no signs of water pump failure. Is this common?
