I'm really hoping someone can help me with this problem which has caused my A3 to be off the road for three weeks now.
Basically the problem is that when the car is started from cold there is a loud metallic rattle which appears to be coming from cylinder 1 accompanied by a puff of blue smoke and also very rough tick over for the first 10 seconds or so.
After that the rattle calms down a little but still there like a noisy tappet coming from the left hand side of the rocker cover which does not go away.
It has been at the garage for the last couple of weeks but they have limited experience with these engines.
Injector 1 is showing -2.0 on flow at start up but this reduces to 0.9 when warm, injector 4 is compensating for injector 1 with positive flow. Injectors 2 & 3 are virtually at zero.
Is it possible that injector 1 could be causing the metallic rattle if it is faulty? It is a Bosch injector which I believe are usually pretty reliable? The garage have examined the cams / followers in situ and say they can see no evidence of wear. The car has only done 68k with FSH.
The garage seem to think that the rattle could be down to timing but I don't think that this would cause the rattle on one cylinder only?
Has anyone experience this before on the BKD engine? The injector seals on injector 1 were changed but this made no difference.
Any advice would be greatly appreciated!!