I have searched long and hard for through the forum with no luck: my car kind of bobbles -- you know, oscillates or what not -- when I am coming to a stop. I checked and the brake pads and rotors look good. What could it be? The things that come to mind are just things I have never messed with before, and don't want to unless it is necessary: parking brake shoes or cable, ABS something (I really don't know how the mechanism work). Anyone else out there has experienced a case of the wobbles?
Originally posted by Fadec40@Dec 12 2004, 11:10 PM Do you feel a "pulsating" action when you apply the brakes? I tmay be the rotors and you would not easily know they're warped just by looking at them.
Pulsating is the word I was looking for. Yes, I feel it when I apply the brakes. Also, I noticed recently that I can hear a subtle, high-pitched sound (which, by the way, also pulsates) when I drive at low speeds -- like in a drive-through. I guess I'll have someone who knows take a look at my rotors. BTW, it's a 96 328i 5-speed. I got it a few weeks ago and have no idea what kind of care it has received.
sounds like warped rotors to me too. The rotors can become warped if they get really hot (for example, can happen if you're driving down a mountain with a fair size load in your car...I know from experience). If rotors are fairly new, they can often be ground back smooth.
__________________ <span style='color:green'>1994 325i </span>- - - 75,000 mi.
No mods - - - very happy as is!
<span style='color:green'>1995 525i </span>- - - 154,000 mi.
No squeaks or rattles... unreal!
To do list:
UUC System U TDM- 3/05
M50 manifold converstion 3/05
off to the tuning shop for custom software 4/05
Cams/lightened flywheel, throttlebody........ well lets see what happens
yah, you can't tell if the rotors are warped by just looking at them, usually varriances of less than a milimeter are enough to cause lots of pulseations.
Warping occurs when things cool down uneavenly. IE: drive around down a bunch with the rotors nice and hot, and then you go to an automatic carwash with sideblasters that pummel the rotors with constant water, QUICKLY reducing one side's temperature, and stressing it.
If it's really bad, I'd just opt to buy a new set or upgrade to slotted/crossdrilled & vented brakes Hell yah.
Alright. Rotors it is then. That was my first guess. I just thought it would be easily noticeable -- tat's why I was thinking maybe it was something else. Any suggestions as to what I should get? How do I know which one(s) is bad. I don't want to change them all if I don't need to. BTW, I am sure its the previous owner's fault, the car was doing that when I got it.
Originally posted by drz328i@Dec 14 2004, 03:17 AM Alright. Rotors it is then. That was my first guess.
As pointed out by the others, Rotors are likely the root cause of your problem.
You may also want to take a look at the Control Arm Bushings.
When the Control Arm Bushings wear out, you feel the pulsating
in the steering while braking. Control Arm Bushings are like $20
and are (realatively speaking) not hard to replace.
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