So many fluids and some carbon

Miles: 110000

Time for some maintenance. Today we changed the following fluids Oil, DSG, LSD(VAQ), and got carbon cleaning done on the intake valves.

This will be the first time doing carbon cleaning on this car. I have yet to have any of the typical side effects of carbon buildup like rough idle, mpg drop, bogging down, or stalling. I’m more doing this as I know Direct Inject engines inherently are problematic for carbon buildup on the intake valves and the car is now at 110k miles without ever having it even looked at it. So I wasn’t sure how much buildup I was going to find. Some people seem to need it at 30k miles but that likely was due to other issues going on to need it that early on.

There are a few different methods of carbon cleaning for the intake valves whether it be chemical or blasting some medium at it. The shop I went to does walnut blasting which is generally thought to be the best method. The walnut is soft enough to not hurt the metal but strong enough to remove carbon. This method requires taking the intake manifold off which means you need a new gasket. Due to the labor in blasting and taking off the manifold labor on this one is much more than the cost of the parts. This is again one of those maintenances where you want a reputable shop doing it.

The shop said I had a “normal amount of carbon buildup” too bad they didn’t take pictures. After the cleaning, I noticed the car to be a bit peppier but also had lots of fluids changed too so who knows what was the real cause.