q7mofo

I just finished the carbon clean out on the Tiguan 2.0TSI
What a nightmare. Valves were severely caked. Three days of cleaning later it now pulls like a train! Night and day difference.

As I looked across the driveway at my Q7 4.2 FSI, my heart truly sinks. Has anyone done this or checked the intake valves for carbon build-up on the 4.2? I know the A8, S6 and S5 guys have complained quite a bit, so I'm curious if anyone else has looked into this.
Thanks in advance!

jarrison

My '08 3.6 was throwing the check engine light code after reset and the dealer determined it was the carbon buildup value problem requiring the full value tear-down. Not covered by warrantee, not covered by CPO. I had to pay almost $1,000 out of pocket for the temorary fix that will comeback as the carbon builds up again. Ridiculous

The real kicker, besides the bill, was that the service tech recommended I hit the accelerator every other day or so to bring the RPMs > 5000k to burn out the carbon. Just like I used to do on my '71 Chevy Nova. Classic. By the way, the tech submitted that solution by email and was subsequently fired.

q7mofo

You're right this is ridiculous.
"My dealership" quoted me $1500 to do the cleaning!!

I think I'm going to try and do this myself.
The Tiguan wasn't that bad. It was mostly soaking time to eat the carbon. Also installed an air/oil separator in between the EGR valve and the intake. So far I've collected about a teaspoon of oil. Hopefully this stretches out the cleaning intervals.

iNfiNkC

funny you posted this, i just posted the same question on another forum.

I plan on doing mine soon. What solvent did you use on your 2.0? ive heard seafoam, but now im reading about BG ISC.

q7mofo

I used a bunch of products.
GM Cleens in an aerosol can worked best.
If your in the U.S. GM calls it Top Engine Cleaner.
I used one can. Two would do a 4.2.

londonsate

I'm going to do it, just wonder how to hand crank the crankshaft.
Do I have to jack the car,put gear in N,etc? Thank you for the help.

SloopJohnB@mac.com

Used to just dribble a quart or so of water down a 4V carb while hot engine running at 2000 rpm…blasts carbon out of hot ports as well as valves and combustion chambers. Not such a good idea with turbo engines when the carbon crap hits the blades, as well as the catalytic converters. Still, might we worth trying and/or methanol/water injection.

SovietBeans

I have a 2005 S4 w/ 127k miles, that's never had its valves cleaned... no idea how they look. Seems to run slightly rougher at idle and through the entire rev range and not quite as fast as it used to be. My Audi dealership quoted me $1800 to clean them. I've heard of people getting this done for less than $1000. Does anyone know of a place in the Dallas area where I can get the carbon removed?

Thanks.

cuatrokoop

I was going to do CRC GDI Cleaner on both the Q7's.

jetsfan101

Just wondering...what years/models for 2.0t engines is carbon buildup bad??

I would like to pick up a 2010-2011 A6 3.0T in the future, is that an issue as well on those vehicles? Or the 3.0T Q7s for that matter??