Audi a4 3.0 misfire. Help!!!
Discussion
Hi there, just after a bit of help here!
I purchased a 2005 a4 convertible 3.0 v6 (asn engine) from a friend with a suspected head gasket problem, No compression on no.1
Stripped engine down and found there to be a hole in the side of the piston! Replaced the piston, head gasket and timing belt. Didnt have the timing tools so set engine to tdc using the mark on the crank pully and made my own tools before stripping it.
After the rebuild, started it up and runs lovely, revs up fine with no codes. As soon as I drive it, it starts to stutter really bad and the engine light flashes. Go and plug it in again and says misfire on 1,2,3. I had the injectors refurbed, all new plugs and new coild on cylinders 1 and 3. Just wondering if anyone has any thoughts that maybe able to help me out a bit here?
Many thanks
Olly
I purchased a 2005 a4 convertible 3.0 v6 (asn engine) from a friend with a suspected head gasket problem, No compression on no.1
Stripped engine down and found there to be a hole in the side of the piston! Replaced the piston, head gasket and timing belt. Didnt have the timing tools so set engine to tdc using the mark on the crank pully and made my own tools before stripping it.
After the rebuild, started it up and runs lovely, revs up fine with no codes. As soon as I drive it, it starts to stutter really bad and the engine light flashes. Go and plug it in again and says misfire on 1,2,3. I had the injectors refurbed, all new plugs and new coild on cylinders 1 and 3. Just wondering if anyone has any thoughts that maybe able to help me out a bit here?
Many thanks
Olly
You need to either use vagcom or the vw diagnostic kit not the hand held OBDI reader this will only give you a generic code. You need to and use it in real time to see whats going on.
As luck would have it i have a family member who works for VW in the workshop so he can get hold of the vw kit And a good friend who has the full Vagcom setup who also is very clued up on all the vw range.
I had a 1.8 petrol focus the other year that lost its fueling table thus putting a hole straight down nb 4 piston. It drove ok thou you could her slight detonation and the plugs were whiter than white and looked like were getting hot. Had Ford reload the fueling table all was ok.
Diesels these days are super complicated esp with DPF and common rail pressures.
As luck would have it i have a family member who works for VW in the workshop so he can get hold of the vw kit And a good friend who has the full Vagcom setup who also is very clued up on all the vw range.
I had a 1.8 petrol focus the other year that lost its fueling table thus putting a hole straight down nb 4 piston. It drove ok thou you could her slight detonation and the plugs were whiter than white and looked like were getting hot. Had Ford reload the fueling table all was ok.
Diesels these days are super complicated esp with DPF and common rail pressures.
OllyV8 said:
Hi there, just after a bit of help here!
I purchased a 2005 a4 convertible 3.0 v6 (asn engine) from a friend with a suspected head gasket problem, No compression on no.1
Stripped engine down and found there to be a hole in the side of the piston! Replaced the piston, head gasket and timing belt. Didnt have the timing tools so set engine to tdc using the mark on the crank pully and made my own tools before stripping it.
After the rebuild, started it up and runs lovely, revs up fine with no codes. As soon as I drive it, it starts to stutter really bad and the engine light flashes. Go and plug it in again and says misfire on 1,2,3. I had the injectors refurbed, all new plugs and new coild on cylinders 1 and 3. Just wondering if anyone has any thoughts that maybe able to help me out a bit here?
Many thanks
Olly
You need to establish which cylinders are not firing, and why. VAGCOM may give you this information ( or it may not )....but more likely you'll need to do some hands on diagnosing.I purchased a 2005 a4 convertible 3.0 v6 (asn engine) from a friend with a suspected head gasket problem, No compression on no.1
Stripped engine down and found there to be a hole in the side of the piston! Replaced the piston, head gasket and timing belt. Didnt have the timing tools so set engine to tdc using the mark on the crank pully and made my own tools before stripping it.
After the rebuild, started it up and runs lovely, revs up fine with no codes. As soon as I drive it, it starts to stutter really bad and the engine light flashes. Go and plug it in again and says misfire on 1,2,3. I had the injectors refurbed, all new plugs and new coild on cylinders 1 and 3. Just wondering if anyone has any thoughts that maybe able to help me out a bit here?
Many thanks
Olly
Check the injectors are getting power and signal during this misfire. Check the coils are getting power and signal during this misfire.
That can at least give some direction as to where to go next
Obviously compression test etc too to check mechanical health of the engine. But it would seem that this problem now, could have been the same problem that led to the piston melting.
stevieturbo said:
You need to establish which cylinders are not firing, and why. VAGCOM may give you this information ( or it may not )....but more likely you'll need to do some hands on diagnosing.
Check the injectors are getting power and signal during this misfire. Check the coils are getting power and signal during this misfire.
That can at least give some direction as to where to go next
Obviously compression test etc too to check mechanical health of the engine. But it would seem that this problem now, could have been the same problem that led to the piston melting.
As above, but one thing that springs to to mind is a blocked/restricted cat on that bank.Check the injectors are getting power and signal during this misfire. Check the coils are getting power and signal during this misfire.
That can at least give some direction as to where to go next
Obviously compression test etc too to check mechanical health of the engine. But it would seem that this problem now, could have been the same problem that led to the piston melting.
This would cause combustion problems that would account for the initial problem and the present running problems.
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