Cant find water leak!!

[ClarCE]

Only filling the header tank up to the half way mark then when im driving the 'coolant level' warning displays on the computer. Temp gauge does not go up though!

I don't know if the sensor has a time delay on reset, but if you're losing it that quickly it may not have time too.  Also these sensors have been known to fail, I've seen it on many a vauxhall, not neccesarily an Omega..

[DaveL]

Jerky could be your breathers need cleaning out.

Does it sound rough and deep when reving first thing, i am asking as mine had a Head Gasket leak and the coolant was going into the pot over night and first thing it was rough as the water was burnt off i think it was the front pot on mine number one.

sniff your header tank see if you can smell exhaust gases or the exhaust to sniff for antifreeze, i had a small test done on mine where a vessel with blue liquid is put on the header tank if it turns yellow it has exhaust gases in the coolant.

Also My Header Tank Cap was knacked from the pressure so i was losing coolant there also

Craig

See if any of your local garages can do a chemical sniff test to see if any exhaust gases are in your coolant. If so then you do have a head gasket prob. If not look at getting another coolant cap to try or look to see if you have wet carpets. Could be a heater matrix leak.  
8-)
DaveL

[Craig_R]

Thinking about it also check the HBV if your alittle Jerky it could of sprayed the Disy Pack over time and corroded it.


The HBV is at the back of the engine you will have to get under the car to check it, its not to bad on a 4 pot you have lots of room compaired to the V6 boys

Craig