[switlikbob]

I know this won't be a feasible option for everyone, but I'm spraying 50/50 methanol and water into my intake stream under boost. I expect this to leave my intake valves sparkling clean.

[Insane_Dawe]

Originally Posted by DrivingPassion

I thought the mixtures of oil, vapor and air is channeled through the PCV into the intake valves?

Yes it does.

I was just bringing up the other carbon buildup issue that not every talks about which could be why buildup isn't as bad on N55s.

[TT1351]

On some of the N54 forums there was talk of an oil catch can to help mitigate carbon buld up, whether this is true or not, I don't know, just sayin.

[M Fifty]

Originally Posted by Insane_Dawe

That is a factor but another huge factor is the valve seals. Depending on the tolerances, some oil will get from the cams onto the valves. BMW may have changed the valve seals to be tighter on a N55.

A thicker a.k.a. fresh oil would help prevent this issue.

So...how do you think the valve stems are lubricated?

[icloudfiles]

I really wish BMW etc. would just come out and say it that it’s needed (your mileage may vary). I had my GTI walnut blasted at 96K. Basically turned it into a new car experience. I’m at 85K on my m2 and I feel like it needs it. Rough cold start and slight idle stutter. GTI would throw a misfire code. M2 hasn’t.

[EDWYER]

Originally Posted by icloudfiles

I’m at 85K on my m2 and I feel like it needs it. Rough cold start and slight idle stutter. GTI would throw a misfire code. M2 hasn’t.

I'm at 87 K and do not have a rough cold start or idle stutter. Do you have a video?

[AmuroRay]

Ive seen a few threads on this - from what I've seen, it's not a big issue on N55s.

https://e84.xbimmers.com/forums/show....php?t=1424121