[G30M]

thanks for sharing your experience

[AP]

Good question. I don’t know but by coincidence was looking at a video the other day titled something like things not to do with a modern car and the mechanic mentioned that cars that have direct injection can be prone to this
Apparently gentle driving can cause it and that the occasional Italian tune up can help to shift it

I’m not a mechanic so don’t know if this is right or not.

Does using premium fuels that supposedly have extra cleaning agents help?

[G30M]

Originally Posted by AP

Good question. I don’t know but by coincidence was looking at a video the other day titled something like things not to do with a modern car and the mechanic mentioned that cars that have direct injection can be prone to this
Apparently gentle driving can cause it and that the occasional Italian tune up can help to shift it

I’m not a mechanic so don’t know if this is right or not.

Does using premium fuels that supposedly have extra cleaning agents help?

fuel isn't getting into the intake port, so no, the intake valves get the carbon from exhaust gas (and engine oil) recirculation. fuel is injected into the cylinder only so the intake is untouched.

some engines have an issue, some engines don't.

i certainly drive my BMWs hard so that should count for something. maybe that vapourises the engine oil so there isn't much recirculating to cause the caking.

[AP]

How would you know you have carbon build up?
Other than opening up the engine ?
Would bmw do that at any of the major services?

[G30M]

Originally Posted by AP

How would you know you have carbon build up?
Other than opening up the engine ?
Would bmw do that at any of the major services?

some owners open it up for some reason, and i am putting this thread here to see if anyone has.

probably not many though. not too concerned, just curious.

[Joe-BMW33]

Originally Posted by AP

How would you know you have carbon build up?
Other than opening up the engine ?
Would bmw do that at any of the major services?

It's a common problem on my VW Tiguan. The symptoms are a bit of a skip when accelerating. Not quite a misfire, but a hesitation type skip. The solution is to blast the manifold with Walnut shells.

I don't think I have ever heard of BMW's having this issue. At least none of the ones I owned.

[H_T]

According to this video, the Italian tune up won’t work because we usually don’t get our cars hot enough for the carbon to burn off.

If anything, aggressive driving will cause the carbon to build up because the optimum temperature for the carbon to build:

https://youtu.be/5C9Ie4BcYew?feature=shared

[G30M]

Originally Posted by H_T

According to this video, the Italian tune up won’t work because we usually don’t get our cars hot enough for the carbon to burn off.

he doesn't know my V8 is hotter than the sun's core.

you don't burn carbon, you just don't want motor oil in the recirculating exhaust gas. it's the oily gas that provides condition for these soot deposits.

hence there are engine oils that specifically made to vaporize less