Hi,
I swapped the complete engine in my Astra for a unit from a breakers yard, which I was told was a good engine. After fitting it when I turn the engine over the coolant bubbles in the header tank similar to when the filler cap is removed when an engine is hot. I can also hear the pressure of escaping air (from the filler cap). Is there a problem with the cooling side or is the engine from the breakers yard bad?
Can anyone help?

John Gregory, August 2007

Thanks for your answer Jim,
I bled the cooling system as per the Haynes manual so do you still think it could be air in the system?
I have to go to a birthday bash today (Sunday) and won't have a lot of time to spend on car.
Will post latest news in a day or so.
Thanks once again,
John.

John Gregory, August 2007

It could be just air in the system as you would have had the coolant hoses off while changing the engine.It should clear itself after about 10 minutes of running.
If not it would suggest a blown head gasket or faulty water pump.
Hope it helps.

Jim, August 2007