E92 strange humming/croaking noise unanswered????

[Mackemshep]

Hi everyone, I'm new here and this is my first post so be gentle . I just bought a new car 2 weeks ago (2008 325i m-sport) car has been great and I love everything about it, however I have noticed a strange humming type moaning noise coming from the car when idle and revs at 1000rpm, it wasn't much of an issue when I first noticed as there are a few strange (electrical) noises come from these cars (so I've heard) and after 2 weeks of searching the "world wide web" I am yet to find anyone or any car to produce the same noise as mine so it's worrying and I know it isn't right and it's also got worse. I am pulling my hair out over it as I've been to 3 garages to check what it is and all said they can't put a finger on it as noise wouldn't come on all the time (typical) bmw also said it would need to be on constant for them to look at it, the reason I am stressing out over it is that although car has warranty it's still under guarantee from the garage I got it from (but 200 miles away) so would like to get a answer so if any issues I can speak to garage. Basically, it doesn't do the noise first thing when started (cold) but will start after about 5 mins of driving every junction I stop at,or in traffic I hear it at idle for 5-10 seconds then ticks over nice, then soon as I touch the throttle (1000rpm) noise comes on and gets louder as car heats up. Then when at running temp it seems to go away and will randomly come and go, it sounds like some fan or pump on its way out,

I will add a video and would be hugely gratefull if anyone can help. Or even say they recognise the noise, thankyou everyone who takes time to help.



http://youtu.be/97yILZ4E1-0

[roofer]

Air con ok? Sounds like the older Disa valve noise, but not sure if yours has one.

[Mackemshep]

Hi, thanks for the reply, yeah a/c is ok and turned it off still there, and how do I know if mine has disa valve?

[HoHoHo]

Just bear with me on this one......

I had an E93 that made a humming noise albeit when on the move rather than when stationary. The problem was simple to address.

The front wings are plastic and they are in fact a slightly loose fit to the front chassis (or whatever it is they join to). Open the front doors, grab the wing and you'll see it move against the body slightly. Not enough to rip them off but they do move. The problem I had (which I understand is common) is at certain engine revs and speeds (at speed due to wind) they vibrate and create a hummmmmmmmm.

I cut some black foam (my car was black) and wedged it between the wing and the body.

Hummmmmmm gone, no more vibration

Worth a try?

[Mackemshep]

Thanks a lot for your reply. That is interesting and will certainly give it a try. Il try anything at the minute. Thanks again

[Mackemshep]

Had car up on ramps today at garage and couldn't diagnose what it was although we did locate it. It's not from the engine bay nor is it the wings or air filter or hoses!!! It's defo mechanical!! It's from under passenger side footwell. If I put my hand on the floor (at bottom right hand side of the car mat) exactly under I can feel the vibrations of some sort of fan or motor. It's certainly mechanical and not electrical as I first thought as when I turn car off I hear the noise kind of grind to a holt! Anyway. Car looks like it's going back to dealer reluctantly for them to sort out under the garentee as I'm not taking the risk of something going and not been covered under warranty thanks for everyone's help!

[mik118811]

I think I read something similar to this and they referred to the noise as a croak, think that turned out to be a pipe which runs underneath the passenger footwell

[Patsy Ann]

Check with BMW franchised dealer. I think there was a modification for this which involved changing the fuel pipes.

[Mackemshep]

Great thanks for that guys. I will certainly look into both your comments. Hopefully either will be right

[Mackemshep]

It certainly does sound like a croak :/

[Mackemshep]

Hi, I found a thread about the fuel line feed which sounded exactly the same as mine and was fixed by renewing the fuel line pipe and clips.it isn't an issue for some and it seems there are some drivers out there happy to put up with the noise as it does no harm, but I'm not able to it's driving me mad literally, so I've ordered parts from bmw and hopefully get car booked into my local garage.plus the car is still under guarantee from the garage and they are paying for it. Hope it sorts it out, I can't thank yous enough for your help guys I will let yous know how it goes. Thanks

[Mackemshep]

Well finally.....car was booked into garage today and the fuel line feed was changed and all is good. Noise is totally gone.car was still under guarantee so dealer picked to the bill, So safe to say I'm one very happy chappy couldn't thank you guys enough. Thanks for all your help. Wouldn't of cracked it without yous cheers