pressure in the tank

[froggy]

Hi, my wifes 306 petrol, there is pressure in the exspansion tank when I take the cap off, when cold. is this right. just taken some air out of the system, would that be the problem? anybody got any ideas? cheers Terry.

[addo]

Is it a 1.4?

[froggy]

yes.

[addo]

It possibly needs a head gasket. Try compression testing before you launch into it, though.

[CitroJim]

I have found that several of my vehicles have managed to hold cooling system pressure for several days at a time. It just showed how well sealed the system was...

Basically, if the engine is not overheating, no coolant is being used and the coolant looks clean then I'd not tend to worry too much.

On a 1.4 a head gasket problem is more likely to show up by an oil leak in corner by the alternator.

If the head gasket is suspect then pop along to your MOT tester and ask him to put his emissions tester sniffer in the header tank. If the gasket is weak then the expansion tank will contain combustion products.

Head gaskets are not difficult on the TU engine, especially the 8V...