Hi im new to the forum.

Ive just bought a Discovery 2 4.0 v8 lpg. Its developed overheating problems, i can drive around all day on petrol and it wont overheat but it will pressurise the cooling system. If you switch over to gas it will overheat instantly, this has been diagnosed as a faulty vapouriser. Its failed a sniffer test and ive done a compression test with 180psi on all cylinders. Ive checked radiator, water pump and put a new thermostat in. Im rather hoping its the head gasket rather than a slipped liner or porous block. Ive also tried k-seal and steel seal to no avail. Any help would be greatly appreciated.

Thanks Shaun