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Subtle Hissing / Fluttering Noise coming for Drivers Side of Car

18K views 16 replies 10 participants last post by  MachRc 
#1 ·
I have this slight hissing / fluttering noise that comes from the driver’s side of the car. If I turn the steering wheel slightly to the left or right, the noise goes away for a brief moment. It seems like the noise is most prevalent when the wheels are straight and the car has had an opportunity to warm up a bit.

Dealer hooked the car up to their computer and said nothing is wrong with the car.

Anyone run into this before / have any suggestions?

Big Thanks in advance,

MD
2001 330XI
 
#5 ·
Hey guys, I got a response from another member who had this problem as well. Turns out he took it to the dealer where they were able to identify that a vacuum hose that originates in the back of the dash to a valve in the exhaust had come loose. Does anyone know about this hose and how to access it?

Any help / guidance would be greatly appreciated!
Matt
 
#6 ·
hose...

i had a similar problem, and it wasn't a huge issue. in my case, a hose was leaking air. the hose was worn due to rubbing one of the steering wheel components.

You can access this particular hose from underneath the steering wheel.

goodluck :thumbsup:
 
#9 ·
it is the vacuum line leading from your manifold to the mpg gauge in your instrument cluster. For some idiot reason, it's routed at the factory to rub against the base of the steering column where it emerges from the firewall in the cabin. Over time, the constant rubbing wears a hole in the vacuum line. That's why it sometimes goes away when you move your steering wheel slightly and why it goes away when you accelerate.

It's pretty easy to temporarily fix/check. Remove the panel underneath your steering wheel - couple screws and pop rivets are all that hold it in. Look towards the very end of the steering column and you should see a thin rubber vacuum line. If it has a hole in it - there's your culprit.

You may think that the sound is actually coming from another portion of the dash - mine seemed like it was coming from the left vent next to the steering wheel. The reason for this is because in that enclosed space, the hissing gets deflected a bit so it's difficult to tell exactly where it's originating from. When I go in this weekend to fix mine for good I'll take a few pics.
 
#10 ·
it can also be vacuum leaks in your engine bay - however, be aware that your intake manifold and various vacuum lines will by their very function make some sucking/hissing noises. I've heard of others having issues with the rubber boot attached to the intake manifold developing cracks, but on mine - the noise wasn't present in the engine bay, only the cabin.
 
#12 ·
you can try electrical tape like I did, but it won't hold for very long - the constant pressure from the vacuum line will eventually work it's way past the tape. The only way to fix the hole is to either splice in some new vacuum line somehow or preferably to replace the entire hose. Don't worry about fixing it ASAP - it won't hurt anything in the meantime, just annoying.

As for removing the panel - it's held on with a couple of those expanding rivets along with some screws. The top edge is held on with a couple snaps that you have to just pop out with a hard tug - it'll almost feel like you might break something but you're not.
 
#14 ·
I had this problem too when I first bought my used 2001. The sound was bad enough that it probably saved me significant $$ because the dealer had no idea what was going on with it, we thought the whole vacuum system might be toast. :mischief:

Its a very simple fix...once you take off the cover under the steering wheel, the hose will be very obvious (black with a blue stripe, if I remember correctly, about 1/4" in diameter). With the way it rubbed against the steering column, the hole was easy to find - it was towards the firewall. I wrapped it in duct tape (which has held for 2 months so far) and tucked the hose out of the way a bit so that the problem would not recur.

Good luck fixing it!
 
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