Faint "rattle" while driving only??
 

Good day gents,
Has anyone noticed a faint "rattle" like a Marble in a can rattle while accelerating in motion?
Ive noticed this about a year ago and recently began my search for the issue... The faint rattle is not present at idle in neutral. I revd up to 5k rpm and no rattle. But the moment its in motion, I start hearing this inconsistent rattle can like sound. I though it might have been my tensioner or deflection pulley, so I just replaced those.. but sound is still there.



I don't want to be throwing $ at this issues so looking for some experiences... its the N52, 230k km, all maintenance has been done on time and well.. wondering if this could be disa valve maybe or something to do with drive train? but like I mentioned, car is driving very well, no hiccups at all.


The noise is like a rattle can noise, inconsistent with how it sounds, BUT no noise while in neutral/Parked and revving...

Sounds like my M54. Ive had the rattle for a couple years same as you. Car functions fine. I did run across at post where it was explained that the rattle was a piece of catalytic converter insides. Made sense to me but I haven't investigating to this day and I read that post months ago! Project at hand not is replacing the sunroof cassette.

after getting under the fat money cow, couldn't find anything.... decided to check my left disa valve and behold!!! broken flap, just rattling in there like no bodies busines.. fuuuuk this car is getting on my nerves as of late lol


going with vaico as that is the only one available around me right now. hopefully it holds

Yeah mine is getting on my nerves too! Panoramic roof, cracked windshield, dipping mirrors, cluster gone haywire...got to keep my composure this storm will be over. But the engine m54 just keeps humming.

good work