Saintsfanatik

Correct me if I'm wrong, but isn't there a TSB on this very problem from Audi? To the degree that they published an owner apology letter, and extended the warrantee to fix this problem on the 3.2 FSI (on their dime, natch) up to 125,000 miles (provided the CEL comes on, with the appropriate code, and the symptoms)?

allenst

videos on YT for cleaning carbon from various Audi's

Willo

Hi I think I was the person who originally posted about this carbon build up and about the absolute hassle I got from Audi who denied it could happen and said it was all my fault.
So...after much grief, the original issue finally was fixed after u posted here!
I religiously use premium gas, highway and long distance drive regularly... I am now at 225,000 km and engine light is coming in again.
A friend of mine told me this is a problem with this model... It comes back!! But Audi is keeping it quiet.
It seems ironic that my first problem occurred at about 106,000 on just out of warranty and here we are 100,000 km later and the problem may be popping up again.
Does anyone know if this is true? Am I in for a $5000 bill?
Any one else out there with high mileage experiencing this again?

Sigq5

Sorry to hear about your trouble with CB
Pls clarify details about your Q5 such as year, engine and whether gas or diesel.
I hope that Audi will be more reasonable given their latest debacle that Audi is facing on diesels.
Good luck

raj99

The 3.2 FSI will inherently have carbon build-up issues due to it's design. Here's a detailed write-up on why the issue exists and what can be done to mitigate it.

https://www.audiworld.com/forums/a6-.../#post24581323

Once you have carbon and need to remove it, the following is the best video I've seen that provides a clear walk-through specific to the 3.2

SloopJohnB@mac.com

Use a media blaster with a custom pipe and a wet/dry vacuum.

Here's one for BMWs:

Welcome to bavauto.com | Media blaster kit - For purchase - Includes media blaster, walnut shell media and Genuine BMW heavy duty aluminum vacuum adapter

The tube could probably be altered/adapted to work on Audi ports.

You still have to remove the intake manifold, etc.

ELEVENS

Oh oh: sorry raj099 and SloopJohnB@mac.com - the carbon problem in the 3.2 FSI that throws the codes has to do with lack of flow in the secondary air injection (SAI) exhaust ports, not the intake manifold. Sure, the 3.2 probably has carbon in the intake runners too, but that won't typically throw a code. The 3.2 has the unique distinction of the SAI carbon problem. At first, the entire front end was removed from the car and the motor pulled to gain access to the ports. More recently, Audi sends a special "carbon buster" team to dealerships with a fancy, custom-made device that clears the carbon in situ. A bit less intrusive and slightly less $$$$, but still a major undertaking. Audi originally denied that the problem existed (imagine that!), but later sent out letters to owners announcing the issue would be warrantied up to 125,000 miles.

My car needed this service at around 50K miles, and 100K miles. There is no doubt whatsoever that it WILL return again. And again, and again. It's inevitable. Climate and cold running may play a role, as the SAI is typically active during engine warmup.

And just to be complete, there is no amount of fuel tank elixirs, Top Tier premium fuel, "drive it like you stole it", or "lead foot tuneups" that will have any effect on the carbon in the SAI. It must be removed manually/physically/mechanically.

Bob Petruska

Does the 125K warranty apply to subsequent owners? If not, when the word gets out not too many people will want to buy used ones.

ELEVENS

Sorry - 120,000 mile warranty and yes, the warranty does apply to subsequent owners.

motoguy128

Sooooo... after 125-150k miles, these cars are junk? Wow. Audi has gotten good at making these cars almost worthless much above 100k miles. A similar Lexus or Acura is worth probably 30% more because of this type of issue. BMW isn't much better.

German engineers seem good at developing clever designs and solutions to problems with long term issues.