2011 BMW E81 vibration noise @1500rpm

**fiuman** · 11-23-2020, 01:27 PM

Greetings fellow forum users, BMW owners and car enthusiasts,

I am in need of your help and hopefully my search for answers will end here. I'll try to keep this as short as possible.

My car is 2011 BMW 1 series E81 118d with an N47 engine in it. I own a car for a year now. So far, the changes I've made are timing chain, flywheel, clutch and brakes.
The problem is the vibration noise that starts at around 1400rpm and lasts until around 1900rpm. The loudest is at around 1600rpm. The noise was present before I made changes (mentioned above) to my car, so it is not caused by them. I've checked with official BMW service and two other mechanics. All three of them said that the exhaust flex pipe should be the cause of this problem. However, it is not. I went to the mechanic who specializes in exhaust and he said that it does not need replacement since it has already been changed. I suppose the car owner before me replaced that flex pipe.
The sound happens both in neutral and in gear and it does not deppend on the speed of the car.
Funny thing about it is that it does not happen 100% of the time. But it does, however, happen 95% of the time. Sometimes it starts immediately after I start the car and begin driving, sometimes it starts after 4-5 minutes of driving which is very strange. The noise loudness can vary from time to time. Sometimes being louder, sometimes being quieter. But it is always present.
I cannot describe this noise, but I did make a video which you can find below and hear it for yourself.

Hopefully, someone will know what is going on. If you need any additional information, I'd be glad to update my post.

Thank you in advance!
PS. Don't mind the airbag error, I know I need to get it fixed.

**Richkid79** · 11-26-2020, 09:15 AM

Funny, mine does this too. Except its on a 2011 128i automatic. It happened after the dealer replaced my torque converter under warranty. I brought it back to them and said its making a vibration type sound at low rpms and they told me its a clamp in the exhaust. Of course my reaction was " Why didnt you replace it and charge me for a clamp?" I got a blank stare. Naturally I wont be going back to that BMW dealer but I have the same problem. Mine is not as loud and is almost unnoticeable with the A/C on. Please update when you find a resolution