over heating after about 3 miles emulsified oil in water expansion tank. Chemical test shows cylinder head to be ok. Water boils over after about 3 miles, system has been flushed and new oil cooler installed and has made no difference ?

peterk, July 2009

i had same problem it was the oil cooler vauxhall wanted over £950 did it my self for just over £100

alan, May 2010

Oil cooler failure is common on the v6 omega. It was probably driven for some time before it was replaced, filling the entire cooling system with that emuusified oily goo. Although now the failed cooler is fixed, the gunge left over is now blocking other parts of the cooling system, notably the radiator, causing the over heating.

Headgasket failure is posible but not so likely on that v6.

VX man, October 2009

Oil in the expansion tank is a sure sign of head gasket failure so I wonder if the test was carried out correctly....the only other reasons for overheating like this is a faulty thermostat or water pump.

John, July 2009