Yup because of the direct injection the N54 requires carbon cleaning. N54 isn't as bad as the RS4 motors, but it still builds up. BMW uses walnut shell blasting to clean it. I'm not sure what Audi's method is. If it's carb cleaners, brushes and some rags, that is one painful method.

 

Terrible.. i was a big fan of 335's motors. lol Looked around on Youtube and just found out that even the Mini Cooper S requires carbon cleaning. I find the more cars get more technologically advanced the harder it is to work on them.

Check the Audi sections, there's a sponsor who performed and documented a few carbon cleanings on RS4s and R8s.

 

Yup really only drawback on the N54, besides the high pressure pumps failing, but that's recalled. Any direct injected motor will have this issue unfortunately. I recall reading somewhere that Lexus maybe working on some sort of setup where an injector will spray at times on the valves to lessen build up.

The N54s don't seem to have quite as bad as build up as the RS4 engines. While RS4 engines are recommended about every 25K the N54 is recommended more between 35-50K. My car now has 50K on it. And at times the idle is rough. This week we should be pulling the intake off and seeing just how bad my valves are.

The good news about all this is. BMW knew this was gonna happen so they seemed to design the intake manifold in a way for very easy removal. The rest of the time is just blasting valves.

 

It does seem like every DI motor will need it. I was wondering, but haven't heard if the 997.2's need the carbon clean? Anyone know? I would assume yes?

 

You're talking about Porsche here...Quality.
Never heard anything of that sort about Mercedes Benz neither.

 

Porsche has its fair share of issues especially with the 996/986 chassis. Wouldn't consider that chassis quality whatsoever. 997/987 definitely seem to be leaps and bounds better though. Though $500 window motors love to set faults and fail for no apparent reason.

Mercedes is notorious for transmission issues especially the 7speed in the Eclass. And then MLs. ML stands for Money Loss with power steering pump failures, wiper motors failing, etc.

All German products have issues. Sad to say I think any of the quality the 997 had will soon be going down hill now that VW has 100% stake in Porsche.