Pearl Black 2004 MG ZT260SE mark 1, V8 for sale

[David]

The valve lets the engine breath and burn crankcase fumes. You can clean it with brake cleaner or petrol.

The only thing I can say, is that the valve sticking open on my car caused weak-mixture warnings and within a fistful of miles overheating to the point that the Concorde-takeoff fan came on. Not good.

That may be a bad luck one-off, but they are cheap things to replace, like the schedule says to do anyway.

David