S4-B8 Secondary Air System Carbon Build Up
 

I was finally able to take in my 2010 S4 6-Sp in for service at Pfaff Audi in Vaughan, to diagnose the engine light that's been ON since Dec 27th. My service advisor called me back 2 hours later to tell me that it was caused by a carbon build up in the secondary air system. They would need to lower the engine in order to clean the system and needed me to leave the car in until Friday.

Luckily my S4 is still under warranty (barely at 70,000 km), and the service advisor told me it was due to the poor quality of our gasoline here in North America, with a higher content of sulphur compared with european gasoline.

I have been searching Audi-related blogs all morning, and besides carbon-related injector issues with the 2.0 engine, I have yet to find substantial information regarding my issue.

Would using Grade 94 rather than 91 help reduce the build up? I am now concerned with having this problem occur again once my warranty is over.

Any information would help... Thanks LS

Re: S4-B8 Secondary Air System Carbon Build Up
 

Check this thread out, it sounds exactly like what you've got going on...

Carbon Buildup...I know its been discussed but I got a surprise yesterday

Re: S4-B8 Secondary Air System Carbon Build Up
 

Thanks for the link. This is remarkably similar to my situation. I too had my last warranty covered maintenance recently, and am facing the end of my warranty (69,000km).

I went by the dealer today and they're working on my car. The service advisor told me that Audi has issued an "update" on this, referring to "opening up" the bores wider to avoid reduce build up, but I have not found anything online with the TSB number provided in the replies.

I'm an aggressive driver and I tend to push my engine quite a bit, so I'm not sure what I can change in my driving habits to avoid this, perhaps starting to use Grade 94 gasoline 100% of the time rather than only 25% of the time, as I cannot afford a $ 6,000 to $ 8,000 repair bill in 2-3 years, and I am not technically inclined to do all the cleanups suggested in the other thread.

Thanks again for the reply and the link.

Re: S4-B8 Secondary Air System Carbon Build Up
 

Your welcome....besides the fellow in the thread yours is only the second b8s4 I've read having this issue.


What grade/brand of gas do you use the other 75% of the time?

Re: S4-B8 Secondary Air System Carbon Build Up
 

Poor gas? No, it's their shitty FSI engine. I have a Q5 3.2 and also have carbon built up.

The Q5 will be my last Audi. Had a 98 A4 and 07 A4 Avant before.

Re: S4-B8 Secondary Air System Carbon Build Up
 

Always Grade 91

Re: S4-B8 Secondary Air System Carbon Build Up
 

I hear you Ed, before my current S4, I had a 2006 A4 3.2 6sp and though I loved a lot of the features in the car, it was a real lemon, I had problems for 3 years out of the 4 years I owned it and the 3.2 engine, I hear, is the worse of all.

I had promised myself I wouldn't buy another Audi, but test driving the S4 got me hooked.

I had a 2001 A4 2.8 5sp. which I adored. That was a truly nice car and we reluctantly sold it in 2011 as a trade-in for a 2011 Mini Countryman, as second car. Fun to drive but 4-bangers are not for my cup of tea.

Re: S4-B8 Secondary Air System Carbon Build Up
 

Any updates on your situation...I guess there's a new method for cleaning that doesnt require dropping the engine....

CEL - Secondary Air System (Carbon Buildup)