Mercedes-Benz M272 3.5L idle

Any idea for this sound?

[RothBeyondTheGrave]

You didn't stay close enough to the engine for long enough at all, but seemingly all 3.5L m272's have piston slap. It somehow miraculously doesn't affect longevity or performance, but that is the sound of a piston slapping against an out of round cylinder.

If it's more pronounced on bank1 than back2, then welcome to the club.

[marius-folkishbadge-]

That tik tik tik sound comes from a sensor that is next to ABS. This is why always there’s a sound “tik tik tik tik”