Weird Noise Coming From 328i - audio

[shane82388]

So a couple days ago my girlfriends 2007 328i started making some weird noise when turned on...it happens both stopped and when moving. It goes "up" slightly when moving so I'm guessing its some moving part. When i first heard it, I thought it was something rubbing on one of the tires, but obviously it wasn't...

I really have no idea where to even start looking...nothing appears out of place at all when you look around under the hood, and it just appeared suddenly.

Any idea what the hell this is?


https://www.youtube.com/watch?v=m7zVZFPqRNY

[shane82388]

Still haven't figured it out...BUMP.

Thanks for any help or ideas.

[shane82388]

After scouring the internet I found some other people with similar sound and very little answers to what could be wrong...some guy on youtube said he had a bad alternator pulley...


I've taken off the belt, spun the pulleys and they seem ok?

- Alternator spins smoothly, with some weight to it, as i believe it should...

- Idler spins smoothly.

- Power steering seems to spin and turn fine...seems to have the most "play" out of the pulleys, but its next to zero really...tons of fresh fluid in reservoir, etc.

- Crank pulley is good and solid.

- A/C pulley is fine, and the vibration really seems to be coming from oil filter housing area and even more vibration from the alternator. Bolts are all tight...


There is a ticking sound coming from other side of engine, sort of near valve cover on passenger side but I think thats unrelated and fairly normal for these cars...


I'd initially guess its the alternator but the pulley spins so smoothly and everything about it seems to be in perfect working order...I don't know how id test to see if its the culprit without eliminating it from the equation, which would require staring the car without the belt on the engine, which I've been told not to do...is this going to seriously mess up something or will it just give an alert on the dash and then be fine like nothing happened when i put the belt back on after the test?

Any thoughts?

[Nikojt]

My sound was from an alternator bearing, but it didn't sound like that... It was louder than a tick and sounded more like a clatter.

[shane82388]

I was just doing some stethescoping on different parts...oil filter housing was kinda loud...power steering pump was kinda loud...alternator was screamin' and clattering...so I'm pretty sure its that at this point...

I was freezing my ass off in the dark trying to figure this out and i was about to give up until tomorrow...i randomly decided id try spraying the alternator pulley with a bit of WD-40 and turning the car on as a last resort hail mary type of thing before i had to order a replacement pulley...

Sure enough, the sound dissipated a lot...couldnt believe it!



I'm not sure if I should get another pulley regardless, even if the WD-40 seemed to reduce/eliminate the noise now?

[CODES]

Check the belt very closely for damage too.
Twist the inside out so you can see cracking or chunks missing.

Sounds like bearing to me though.