Omega V6 Overheating

Waterpump is driven by the cam belt. Thermostat is above/in front of it it. Vauxhall only sell it as an assembly with the large lump of metal pipe work attached to it! I guess you are assuming the 'stat has failed shut, could you check this my seeing if the rad gets hot? You might have a blocked radiator? Check for cold spots.

Will

Cheers Will, I didn't think of that, just hope it's not the water pump :-( looking at a lot of dosh me thinks.

Dave

Maybe a pressure check, or a new expansion tank cap might work too, as if there is not enough pressure, the system will boil .

Graham

Will look in to that one too, thanks Graham.

Dave

Waterpump is driven by the multi-V belt at the front of the engine (same belt that drives the alternator and power steering pump). The thermostat can be found in the valley between the two banks of cylinders, just behind the water pump. The easiest way to find it is to follow the radiator top hose back to where it joins the engine.

It sounds as though the system is overpressurising, which is causing the expulsion of coolant. A coolant system pressure test is probably the next best step - a hand operated pump is connected to the expansion tank and used to pressurise the system to 1bar. This is then left for a few minutes to see if the pressure reading drops, which would indicate a leak. A pressure drop with no signs of an external leak would point to a head gasket leak or other internal fault. The most comon fault on a V6 is the oil cooler going porous, but this would give oil in the coolant which you have already checked for.

HTH

Anthony Remove eight from email to reply.

Yep, sorry for the misinformation! I replaced mine when I did the cambelt, and got mixed up; the water pump's shaft extends so it clears the cam belt to be driven by the aux belt. I remember being surprised by how cheap it was, 20quid I think, which led me to believe they either fail all the time or never fail! I remember the thermostat was more expensive!

Keep well,

Will