[psybience]

Hi,

I recently bought a 2010 E92 330i (36k miles) and whilst the car drives fine with no lights on the dashboard, I get this odd intermittent noise coming from under the car from what sounds like the engine bay. It's like a grinding or metallic rattle, very much like what you hear when accelerating in a diesel van.

It happens when I accelerate from lower rpms and goes away when you climb up the rpms, although I think its still there, just less noticeable. It only happens when in gear, not when the engine is revved at idle or with the clutch in. It doesn't always happen, but usually starts after I've driven the car for a bit. Other times, it starts happening then goes away again. The intensity of the sound can vary; sometimes its hardly noticeable, other times I feel like I'm driving a van. I don't think it affects the performance in any way, but it's certainly makes driving a lot less enjoyable and refined.

I'm not entirely sure what conditions cause it to happen as its quite random, but what I have noticed is that it hasn't happened after a cold start (like in the morning or after the car has been sitting for a while). I feel like it's something related to temperature, but can't be sure.

Lastly one other thing I have notice which may or may not be related is that, when I turn the engine off, I hear a similar rattle noise coming from the engine bay, but much louder. However if I dip the clutch in and turn off, I hear little or no noise.

I've tried to research this problem, but getting lots of reasons for such noises on BMWs. The only thing I can think of is that the clutch or dmf is causing the noise, but the car is only 36k miles. This is my first bmw or any german car for that matter and I'm not very knowledgeable on these things, so would appreciate some help on this matter! The issue is really bugging me because when the noise is not there the car feels and sounds so nice, but as soon as it starts it spoils the fun.

[frenchi]

Does it sound more like gear mesh grinding or a low frequency vibration,you got an N53 engine and these are known to have some unpleasant noise from high pressure fuel pipes. Could be also throttle body or Disa.
Try to post a video so we could try to help you.

[StealYourFace]

Goes away when you press the clutch? First guess would be the through out bearing.