ELEVENS

They don't have to pull the motor anymore. "All" they have to do now (with their special-built Audi carbon-cleaning tool) is to pull the entire front end off your can to get to the exhaust ports. It's a bit easier and takes less time than pulling the motor. Still a several-day job though! Either way, quite invasive indeed.

Ben Burlinson

UPDATE: I am a bit hot as the audi dealership has informed me that it is a intake manifold tuning valve. The wires have somehow just magically pulled out of the clip, picture attached. Funny how no one has touched the car but them. I wonder how wires just come out? Do they take me for an idiot? Not to mention it is $400 to replace the electrical clip and then they can continue to diagnose. It has been repaired by a independent German shop, they didn't even charge me. I will wait to see if the mil comes back on. Moral of the story, when you go to the dealership and they disappear in the back with your car, who knows what they are doing. I will give them the benefit of the doubt for now.

Ben Burlinson

Thanks, been a bit of a ride but we will see how it turns out.

Sigq5

The Audi dealer offers an induction service (about $200) that is intended to clean out CB (U-Tube has a couple of excellent videos).

The technician needs to be thorough to get all CB out and careful not to damage catalytic converter.

Not sure how good this service is after the CB is too much. It appears that doing this as preventative maintenance might be a better strategy.

Many people gun their engines from time to time to burn the CB out.

Wishing you best of luck

ELEVENS

Actually the 3.2L Q5 carbon problem isn't even IN the induction system

Sigq5

Good info.
Does anyone have any experience with carbon build up with the TDI engines?
Thx

idale

Carbon isn't an issue on the TDI, the DPF (diesel particulate filter) is the topic that comes up most frequently there. I think the current gen shouldn't have an issue with it anymore due to the car not letting the regen cycle get interrupted, but it's something to be aware of (and the typical prevention step is to occasionally keep the load on the engine high to heat up the exhaust and help anything caught in the filter get burned up -- regen will do this on its own from time to time, but it doesn't hurt to help things along).

Sigq5

The Induction Service that many Audi dealers offer consists of running chemicals through intake plenum to cylinders. The intent is to clean up the CB. Check out U-Tube to see how it is done. Audi charges about US$200.

I do not know why they call it Induction Service. ;-).

If interested in this service, Pls be very careful who does it for you since chemicals can damage catalytic converter.

The best option is having Audi get into the head and engine to clean the CB.

Wishing you best of luck.

Sigq5

Thank you for your excellent suggestion.
We specifically went TDI to reduce risk from CB.
As you suggested we'll do the "Italian tune up" aka "a redline a day keeps Audi doctor away"

ELEVENS

Right, the "induction Service" is named well Induction Service, fuel additives, and leadfoot tuneups are always suggested as old solutions that don't work on a new problem. So to beat the dead horse again, the 3.2 carbon problem isn't in the intake plenum, intake ports, or cylinders. It's in the secondary exhaust ports. Chemicals introduced into the intake is not going to survive the combustion chamber to do any good in the SAI ports.

In fact, the Induction service does little to nothing to the carbon problems in the induction system of Audi's FSI motors, such as in my RS4. This is not only widely reported, I know this first hand. Over several thousand miles, I've introduced multiple cans of Seafoam, BG Induction Cleaner, GM Induction cleaner, and gasoline into the induction system on my RS4 using a special port located at the rear of the intake manifold. The port is located such that it discriminates cylinders. IOW, the distribution is not uniform over all 8 cylinders so the effects of the chemicals appear at the rear cylinders. Subsequent tear downs and inspections showed the effect of the chemicals were, at best, a slight softening of the carbon. That makes the dirty, tedious job of manually scraping the carbon off the intake valves and intake ports every so slightly easier. The Q5 may too have this problem but the 3.2 SAI carbon problem is so much worse, it overshadows any intake carbon problem.

So in a nutshell, Induction Service on an FSI Audi is a financial enrichment program for the dealer. It probably does wonders to clean the throttle body plate. A $4 can of aerosol TB cleaner is more thorough and MUCH cheaper! These aren't pre-FSI motors we're talking about where induction service actually work quit well. I believe that's the problem in its entirety with the whole Induction Service thing. It's a well-know solution that was proven to work on NON-FSI motors. Even respected mechanics not up to speed on FSI technology, mis-advise Induction Service for FSI motors because it worked so well up to this point (Audi FSI motor).