I have been through a few frustrating weeks with the car, so I thought I had better update you all
After Stoneleigh I noticed that I was getting some oil in the coolant expansion tank, but the coolant was not getting into the engine.
My first thought was that the oil cooler had gone, so I bypassed this. No improvement.
So after several sessions of draining coolant, flushing the system, refilling and test driving, the problem was getting gradually worse.
It eventually got to the point where the coolant was expanding through the complete depth of the coolant expansion tank and out of the top of it.
So I decided that It must be Head Gasket Failure.
There was nothing else for it but to strip the head off and see what was there.
I managed to get the exhaust manifold off in situ, but there was absolutely no way I could get to all the inlet manifold bolts, so the head came off with the inlet manifold intact.
This left the top of the block and gasket exposed
Plenty of caramel to be seen, especially on the inlet side
Next up was to strip off the inlet manifold, and then out with the cams and followers from the head
Then It was a pressure test (all good) followed by a five thou skim on the head
I then re-assembled the engine, filled it up with fresh oil and plain water with a degreaser was added to the cooling system. A test run followed and upon return to the garage for inspection, I noticed a coolant leak on the front of the engine.
Further investigation the next day pointed towards the water pump, so there was nothing for it other than to strip down the front of the engine again to remove the water pump.
I decided to just replace the water pump, so ordered one and waited for it to arrive.
Whilst the front of the engine was stripped again, I decided to discard the old thermostat housing. All it was doing was housing the cold start temperature sensor, so I came up with a modified arrangement.
From this
To this
The water pump arrived last weekend, so I fitted it and put everything back together again on the front of the engine. I am now well experienced in timing up the engine, having done it a few times in the last few weeks!
I refilled the cooling system again including a degreasing additive, and gave it a test run. The leak at the front of the engine was cured.
Finally, during the course of the week I drained down the cooling system again, and then flushed it all with a hosepipe now the ban has lifted.
A final refill of the cooling system with new antifreeze mixture last night meant I could give it a proper blat out today.
I am relieved and pleased to say that the car is running great again, and touch wood all looks well with HG/Coolant/Oil