Wife's 2.2 "B" petrol,Just had a new water pump and radiator fitted.
Drove it for maybe 2 miles (from cold) and it Bl***dy overheated again!
(Heater went cold at the same time!)
Thought it might be an air lock, so carefully refilled the coolant with the rad cap off and let the air bubble out.
It was fine for maybe 20 miles with a couple of very short stops (so the engine didn't really cool down a lot)
Anyway, the wife went to use it in the evening..... same thing! overheated within a couple of miles! from cold!
What seems to be happening when it overheats is that the coolant seems to be being pumped into the expansion tank until it fills and overflows!
Again today,after filling up again, this time bleeding the air off via the thermostat housing - it ran great for another trip of 15 miles or so.
Once the engine had cooled and I started on the return journey it starts to overheat again!
So........
Symptoms seem to be :
Heater suddenly goes cold,
temp guage starts to rise rapidly
Coolant gets pumped into expansion tank and overflows it.
I tried another rad cap in case the one that came with the new (Genuine Opel) was weak and not holding pressure.
Didn't make a great deal of difference!
This is really doing my head in....... I'm truly sick of this car now....... Any thoughts would be most appreciated.
I'm thinking maybe the thermostat???


















