Originally Posted by GAaaAR
Wow this sounds pretty bad. But honestly I've been a member of this forum for awhile now and have heard about this siren noise way in the beginning already on 2007 models years ago. If this is in fact so bad, why haven't we heard of any cases of turbos failing yet? This poll points to the majority of users having this noise and multiply that by 5 years worth of 335i users tuning their cars with the majority having experienced this noise for years, yet pretty much no one has had their turbos fail yet from this noise. I'm sure if we dig hard enough there might be 1 or 2 cases but those cases can have other variables as well that caused it. Perhaps its not that bad?
FWIW, I have this noise and it went down alot when i took out the tune or when I installed the stock air box. Do both and I'm pretty sure its quiet again.
My car is now 100% stock and it sounds the same. I have had the normal spool sound on this car, and another n54 I had- there is a huge difference between that sound (which I think most people are thinking of when they say yes) and the one I'm experiencing.