AO Gold Member
Join Date: May 2008
Location: United Kingdom
County: Perth and Kinross
Bad timing if it has gone...if it had been done at the same time as the belt change it wouldn't have hurt so much.
But....get the header tank sniff-tested (any garage will be able to do this for you). It *might* be a faulty oil cooler, although you normally only get the oil/water mixing one way (can't remember which way either...).
The water system will pressurise when the engine is hot. If you're seeing a boiling-effect in the expansion tank though, it probably is the head gasket...