Quote:
Originally Posted by adrianhan
Hi everyone, I thought this is an appropriate thread to ask a question too about an engine noise.
My car is a 2006, 330i, n52, 93k miles.
I had the serpentine belt break on me as I was pulling out of garage. I replaced it and as soon as I started the engine it was running rough, checked the codes and it was a misfire on cylinder 2 and MAF sensor (which was not giving me any problems but it started right after I decided that probably is not a bad idea to clean it).
Replaced the plugs and the coils, car is running a lot better, unplugged the MAF (plugged in still runs a little rough), but with or without the MAF (new MAF is arriving tomorrow), there is a new continuous rumble, engine cold or hot, and I was wondering if anyone knows what could be the issue.
Here is a video of it.
I am not sure how breaking the serpentine belt could cause that, but I never heard that noise before. Is pretty loud an can be heard from inside the car too. Did NOT notice any impact while driving, performance wise, etc... just a nasty noise. The noise seems to be coming from below the intake towards the windshield... at least that's where I think the sound is coming from. I cannot seem to hear it anymore when I accelerate.
Thank you in advance for any input you might have. |
Sounds something plastic loose rattling in closed place. You have 330 which has an intake manifold with two DISA valves on it. One of them may have gotten broken and lose rattling inside. That is one possibility that comes to my mind. If you search for DISA on N52 you will find lots of information.
The other from your description "The noise seems to be coming from below the intake towards the windshield", the crank case ventilation valve that is tucked inside the folds of the intake manifold towards the windshield (firewall) side may have ruptured its membrane and flapping.
There is also possibility that some of the serpentine belt got thrashed to pieces and sucked into the engine through the front crankshaft seal. It is hard to believe this can happen there have been many reports on this, even pictures from inside engine with pieces of belt stuck at the oil pick up line filter. Maybe some piece got also made its way from the crank case into the crank case ventilation valve and flapping around there.
There is also possibility the belt swung and took out some breather line made it loose and rattling.
Good luck!