Originally posted by JEDsContour:
Originally posted by SableSal:
Originally posted by JEDsContour:
Do you have a V6? The 2.5L's are notorious for water pump deterioration. Relatively cheap and easy fix ââ?¬â?? 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?





Sal


Yes I think water pump. The plastic impellor comes loose from the shaft. No leakage, bearing is still good, no water is pumped.

Localized boiling in the engine will produce enough vapor to force out coolant.

Change the water pump. Simple job.

P.S. Why did you post this in 3.0L Duratec?




Don't forget that it is only the OLD contour plastic impeller pumps that would go without warning.

The new pumps with the white impeller are pretty reliable now.

Former owner of '99 CSVT - Silver #222/2760 356/334 wHP/TQ at 10psi on pump gas! See My Mods '05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red '06 Mazda5 Touring, 5spd,MTX, Black