Build up of deposits on intake valves and ports

[mlhj83]

Just out of interest, how will you guys be addressing this issue? Do you have a set mileage interval as to when you will have it cleaned? And what is your preferable method of having it cleaned, e.g. walnut shell, scrubbing? Has your BMW dealership offered this service and for how much? While I'm obviously not a 1M owner, I'm interested to know given that direct injection is going to be standard across all M engines.

[Jezzer]

Direct injection is a real problem with sooting up the intakes. Audi have problems with the RS4/R8 V8 engine and early inspections after just 3 to 4 k miles revealed really bad contamination. Friends of mine have had this done using the walnut shell method but it seems it back again within a few thousand miles.

[SNOOPY11]

Originally Posted by Jezzer

Direct injection is a real problem with sooting up the intakes. Audi have problems with the RS4/R8 V8 engine and early inspections after just 3 to 4 k miles revealed really bad contamination. Friends of mine have had this done using the walnut shell method but it seems it back again within a few thousand miles.

Thanks for reminding me... Won't be long until my RS will need some scrubbing bubbles..

The reason why Audi fsi motors suffer from carbon buildup is due to internal egr which occurs during cam overlap. You can try to mitigate by calibrating/decreasing that little window but it will be at the cost of performance. Increase it for additional umph and you'll have more cb. Lose/lose.

Before concluding this, many owners thought cb was occurring due to faulty oil catch cans but Audi had already engineered a cyclonic oil separator which was more than up to the task.

Haven't really read up on deposit formation on BMW DI motors. What are owners doing to remedy, if anything?

[mlhj83]

Build up of deposits in the N54 is a known issue, and it is still an issue even for the latest DI engines(any manufacturer), although they tend to build up more slowly. A google search will show N54s with significant build up at 30-40k miles. Thus, I was wondering what 1M owners will be doing to in terms of cleaning and at what intervals, and also costs. I know of a few that have already exceeded 20k miles.

[h-manuk]

I've seen oil catch cans which are available, do these help address this issue?

[mlhj83]

Originally Posted by h-manuk

I've seen oil catch cans which are available, do these help address this issue?

It does help a little, but it doesn't prevent it unfortunately.