A4 sline smoking

[Lee A]

Hi I’m having problems with a4 2.0 tdi, when starting from cold it fills the road with grey/white smoke, runs lumpy and stalls if you try to pull away, when warm it has no low down power until the revs hit about 2000rpm when it will take off and fill the road with black smoke, it’s been in the garage for 5 weeks they fitted a mass air flow sensor, map sensor, turbo, turbo pipes, injectors, they returned it yesterday and said there was nothing more they can do, has anybody else had these problems and what was the cause, any help would be grateful received 

[Steve Q]

Welcome to the forum bLee, you'll find the members on here are a friendly and helpful bunch :) 

Wow, you've had alot of work carried out! I'm assuming the garage have done a diagnostic check? 

And have they checked the dpf, egr or pistons? 

Cheers

Steve

[Magnet]

Hello Lee, 

Sorry to hear of your issues. It seems to have been an expensive route to nowhere at the moment. Apologies for not being too up on diesels, but I would ask if the garage who has been carrying out this work are diesel specialists or not. It is my belief that diesel specialist garages are the only way to go for such issues. 

From my very limited experience, I would have thought that fuel pressure being within spec. the next port of call would be a leak-back text on the injectors since this does seem to be typical  of injector problems. Of course, your garage may well have been down this route, and if so, it may well be with asking where they sourced their injectors etc. 

Sorry I cannot point you in any other direction. 

Kind regards,

Gareth.

[Lee A]

Thanks for the advice, I have found a specialist locally so will get it booked in for a   Diagnostic next week 

[Steve Q]

Please keep us posted Lee, I do hope it gets sorted quickly.

Cheers

Steve

[Lee A]

Had the diagnostic done and turned out to be the EGR valve, they also discovered that the new turbo is massively over boosting so I don’t recommend buying a cheap Chinese turbo

[Steve Q]

9 hours ago, Lee A said:

Had the diagnostic done and turned out to be the EGR valve, they also discovered that the new turbo is massively over boosting so I don’t recommend buying a cheap Chinese turbo

Unfortunately egr failure is common, have you had the emissions recall at all? 

With regard to turbos the opinions are to buy a reconditioned genuine one or buy a new genuine one unfortunately. 

Cheers

Steve

[Lee A]

Thanks for your reply Steve, and no I haven’t had a recall, the car is booked in Thursday to have a genuine turbo fitted with a 12 month no hassle warranty, but it drives so much better already just advised not to drive it to hard as that will cause the over boost and switch on the limp home mode

[Steve Q]

4 hours ago, Lee A said:

Thanks for your reply Steve, and no I haven’t had a recall, the car is booked in Thursday to have a genuine turbo fitted with a 12 month no hassle warranty, but it drives so much better already just advised not to drive it to hard as that will cause the over boost and switch on the limp home mode

You're welcome, glad I could help :) 

Once the new turbo is fitted you should have your a4 back to normal :) 

Cheers

Steve