Sounds like the EV, our most common fault.
If you have access to the expansion vessel valve (looks like a car tyre valve) it should be around 21psi when measured.
Also check the pressure relief pipe if its letting water by it'll also need replacing.
Currently driving an Alpina-D3 MT, Sapphire black, Classic Alloys wrapped in PS2's, Full Alpina interior trim, Black Grilles, Blackline tail lights and zymol'ed once a month.
Last edited by Jedimindtrix; 12-23-2012 at 08:10 AM.