Audi A3 2.0TDI (BKD) Rattle and Smoke on Startup

[simmo192]

Hi All,

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!!

 

[TDI140]

Has the car been remapped ? Also get vag come scan done to see what the issue is

 

[simmo192]

I don't think the car has been remapped not in the time that I have owned it.

VAGCOM shows no faults found just lowish flow on injector 1.

 

[simmo192]

SOLVED! It turns out that the timing was out by two teeth and the noise was valve against piston

Apparently running perfect now will collect tonight!

 

[Geraldy212]

Sorry to be negative, but with the possibility of valves hitting pistons, I would immediately go for a simple compression test. Any loss of compression could indicate a bent valve stem. If OK, you have indeed been lucky. However, how come the timing was that far out? Has someone changed the timing belt? If not, I would worry about the timing belt tensioner.

 

[TDI140]

Wow my bmw timing chain ws out two teeth and it bent a valve had to rebuild engine

 

[simmo192]

I think I was very lucky and that the valve was just touching the piston at the end of the travel.

When I bought the car it had been accident damaged and I now have my suspicions that the cambelt may have been nipped during the collision causing a jump of two teeth. A new belt and water pump has now been fitted and the engine is running quiet so hopefully there will be no lasting damage.

 

[TDI140]

Very lucky

Good on ya pal