Author Topic: My car is making a vacuum sound. (Read 3728 times)

92BMW318is · « **on:** April 27, 2010, 01:00:03 AM »

So recently i just replace the starter once agian after visiting Chicago, i let a girl drive my car and she stalled out the car and turned it back on and the key got stuck on the start position. so i had to pop the clutch every time i turned it off.
i probally ended up poping the clutch like 7 times before i put the new starter in,

Sooo after i put the starter in my car started to make this winding down sound like a vacuum being turned off, like one of those industrial heavy duty vacuums.
But... it only does it only at certain times..

1. it does it when i take my foot off the gas.
2. it does it when i use brake.

it doesnt do it when

1. when i accelerate
2. when i push in the clutch
3. when im idling

At higher speeds the sound is at a higher tone,
lower speeds the tone is lower

Please if you have any idea what this might be let me know ha,
i have no idea wtf is making that noise

EDIT, the sound is comming from the back of the car.
at lower speeds like 1-15mph theres a suddle grinding noise

EDIT, Here is a video with me driving and the car making the noise

http://www.youtube.com/watch?v=BhcDbExz1c8

i took a picture of what i thought BlueBmw was talking about
http://img203.imageshack.us/i/imag0827.gif/
http://img706.imageshack.us/i/imag0826.gif/
http://img710.imageshack.us/i/imag0825.gif/
http://img199.imageshack.us/i/imag0824.gif/

dvmotorsports · « **Reply #1 on:** April 27, 2010, 12:06:34 PM »

How do your brakes feel? Sounds like you may have knocked a vacuum line loose or broke it somewhere near the booster.

92BMW318is · « **Reply #2 on:** April 27, 2010, 03:34:28 PM »

the brakes work fine, i do have disc brakes they are not drum.
i have them on all 4 wheels. whats a booster where would that be.

BlueBMW · « **Reply #3 on:** April 27, 2010, 04:00:06 PM »

The brake booster is that large round thing attached to the firewall that your brake master cylinder and fluid reservoir are attached to. There should be a large hose attached to it (maybe 3/4" diameter?) make sure that connection isn't loose or damaged.

92BMW318is · « **Reply #4 on:** April 27, 2010, 10:14:14 PM »

http://www.youtube.com/watch?v=BhcDbExz1c8

Watch this video, look in the comment section too

PumpItUp · « **Reply #5 on:** April 28, 2010, 06:13:23 AM »

sounds like transmission or wheel bearing (not from your video which was useless :-) digicam's integrated mic isn't good for this sort of thing)

if its transmission you'll be able to tell more clearly if you remove the shift boot and dislodge the rubber under it so more noise gets thru

wheel bearing would probably depend purely on speed (higher mph = louder)

stupid girl broke your starter. :mad: i gave my sister my keys one time to get something out of my car. next morning i notice my driver side lock is all stripped and jammed. power doors have 3 points, she probably hacked at it, women just don't respect certain things/take them for granted. $100 new lock from bavarian autoparts, didn't see it elsewhere. sometimes they can be fixed, but in the meantime, passenger side operation. :cool:

edit:
okay i reread your post.
its 90% the drive shaft, because a bearing would get damaged unless that girl also hit a curb or something. its probably the guibo falling apart. or any parts which require service but you skipped. driveshaft itself wont get damaged, but the links might (in the middle or on the edges). get a bright white flashlight and look under the car, not from the muffler side. take pictures of the very front, back, and middle of the drive shaft and show us.

too bad there isn't a one piece (carbon fiber :0)? driveshaft we could buy...

92BMW318is · « **Reply #6 on:** April 28, 2010, 10:49:15 AM »

well im about to put on 2 new front stablizer links my dude has a lift so ill get some pics and put them up, but for some reason i can never get them to work on here? is there som kinda trick?:confused::confused::confused::confused::confused::confused:

92BMW318is · « **Reply #7 on:** April 28, 2010, 04:35:23 PM »

okay, soo its the rear final drive and or the DIFFERENTIAL

PumpItUp · « **Reply #8 on:** April 29, 2010, 04:59:35 AM »

howd you diagnose that?
and your 92 came with open diff right, might as well upgrade to lsd.
from the e36 automatic's for the short ratio 3.73 i think.

if you're in a hurry go to a dismantler, if not junkyard or whatever, you can get a used open diff for like $150 sometimes, lsd will be at least 250. new lsd $750-1500 and it might be just the rebuild kit. btw use good oil this time