NHman

There's an article highlighting the key features and thought process for the 3.0T engine in the S4 and S5 variants. Full disclosure, this was referenced on another website but I found it interesting enough to share with this forum.

Link to article
Technical Analysis: Audi?s New 3.0L Turbo V6 | YouWheel - Your Car Expert

antman0505

I'm new to Audi but I've been reading that there have been issues with carbon deposits resulting from the use of direct injection technology in some of their engines. This article mentions that this engine uses a slightly different DI design.

My question for the more technically minded members:
1. Is this something I really need to worry about in the longer term?
2. Will this design change reduce the issue with carbon build up?
3. Is there anything I can do to minimise this becoming issue?

Thanks.

markcincinnati

Call me OC, but I ALWAYS use top tier gasoline. Never have had any problems.

http://www.toptiergas.com/licensedbrands/

JohnEnglish

It was an issue on earlier Audi DI engines regardless of what gasoline you used. It's nothing to be really concerned about with new Audi DI engines.

markcincinnati

I agree with JohnEnglish.

Re: your question 3 - using Top Tier gasoline still has its merits, and, oddly, if you have access to Costco, will actually cost less. Locally (Cincinnati) Shell has an arrangement with Kroger that allows Kroger fuel points to be used at Shell stations to reduce the per gallon price.

Hmm, wonder if/when Amazon will be getting into fuel?

snagitseven

Much has been written about this. All DI engines, by virtue of their inherent design, can have issues with carbon deposits to one degree or another. Since the explosion does not occur at the valves, which would normally help keep them clean, there is a chance there will be some coking over time. The latest methods of carbon removal, including the use of the relatively inexpensive crushed walnut shell process, make cleaning less of a major deal. (Much less costly than a timing belt change which of course, most the Audi DI engines do not employ).

BTW, it has been shown that using Top Tier fuel in DI engines does not help much for the reasons mentioned above. It can help keep the fuel lines clean but won't affect any carbon deposits on the valves as the fuel doesn't come in contact with them.

antman0505

Thanks for the reassuring info.

James Cole

Found some more info:

3.0T self study: https://www.yumpu.com/en/document/vi...5/ssp655-wg-en

James Cole

The study also says the engine is rated for 0w-20 oil... it doesn't seem right.

Johndefiore

Wow, that's a really interesting read, though I wish there was some way to download it for offline viewing. It does say "For internal use only" so I'm not sure we're supposed to have access to it but still would love to have a copy.