L322 4.4 BMW V8 coolant over pressure

Chaps,

Having a bit of a nightmare with the RR - the coolant system seems to be over pressurising but not over heating.

Today the expansion tank blew (split along the side), a couple of weeks back it was the top hose.

There's no white gunk in the oil but I'm wondering is the engine is pressurising the system?

I'm surprised that the cap on the expansion tank didn't vent - or am I being horribly old fashioned and these things don't vent anymore?

I've replaced the theromostat and the viscous coupling, the radiator and the water pump were done about six months ago.

Any thoughts?

get garage to use gas analyser to sniff test coolant for HC if it jumps =head gasket or cracked head etc

It has an LPG coversion, I'm just wondering if the vapouriser is pressurising the system?

Duke Thrust said:

It has an LPG coversion, I'm just wondering if the vapouriser is pressurising the system?

Click to expand...

possible,run it on petrol and if all symptoms disappear=answer

also you should smell lpg smell v petrol in coolant