Hi Ron,
It's a pity I didn't see your reply earlier !!
Today:
The compression tester arrived and I did a compression test,*
Cylinder 1: 500psi
Cylinder 2: 510psi
Cylinder 3: 500psi
Cylinder 4: 510psi
So all at around 35bar
I then moved onto removing the inlet manifold, disconnecting the injector wiring loom and turned the engine over, all the cylinders were sucking but no2 was puffing back as well as sucking.
Reconnected the injector loom and started her up, definitely could hear the blowing back and popping coming from no2. Also found that there was no carbon buildup on the inlet manifold and cylinder head ports on cylinder no 2. Indicating the blowback is burning off the **** in the inlet.
Took the front end off and checked the timing. All ok
So ended up doing what 2 AA technicians, 8 mechanics and 3 engineers said it was and removed the cylinder head (regardless off the compression test being ok)*
Unfortunately have found nothing, no cracked valves, valve seat is ok, piston is ok, head gasket and mating surface marks show no indications of passing, the only thing I found is there is no carbon buildup around the outer circle on cylinder 2 inlet valve, indicating the edges of this valve are getting hot.*
(yes should've believed the compression test)
The only thing I can think of now is one of the injectors is injecting diesel prematurely, causing the issue.*
Have you read the pd engine document on my original post?*
So for now I have to get the head skimmed and get the injector tested!!
(and buy lots of parts, might as well do the belt, water pump, tensioners etc)*
Ron: what is your engine code ? How many miles ? Can you get the Inlet manifold of and check which cylinder is blowing back ?and swap the injector over and see if the problem persists.
Where abouts are you in the uk ?*
Look forward to hearing back ...