I keep hoping that my intake manifold will fail soon so I can get it replaced under the 10-year warranty. And of course to get a deal on the carbon cleaning while they're in there.
So was I but thanks to some great coding by VW mine never 'failed' until 1500 kms after that extended 193,000 kms warranty.
I'm sure it could use a cleaning by now, but can't say as I've noticed any performance loss or other issues. Did you notice it running any better after the cleaning?
Yes I noticed it running better after the cleaning. Going back, I only had minor issues at very weird times but not very often. IE: under light load (~20% throttle) it would feel like it wasn't firing correctly (pinging?). But just push a little more on the throttle and problem solved. Of course, the number of times I use light throttle is very rare.
Also on cold start up it never sounded 100% right, odd but quiet farts through the exhaust. I don't think many people would notice it but I could.
When I (cold) started my car yesterday morning it was very smooth and normal sounding. I noticed a difference right away. I also think the engine is smoother through the rev range. Not that it was rough but I can feel a difference.
I'm now looking forward to doing some hwy driving to see if there is a difference in f/e. It has been so windy this summer I've been up 0.5-1.0 L/100 on many trips from normal but maybe it was just because of the carbon build up.
I see it as gaining weight. The carbon build up was over a long time and changes were very small when they happen. So it was like putting on 20 pounds over 6 years. Then had a magic weight loss in one day and I looked in the mirror and said, wow, I was fat.
This questions isn't if you have any carbon build up, it is how much do you have. Good luck and hope you can get VW to do yours when it's time.