Almost constant squeaking at lower speeds - 99 E300TD - PeachParts Mercedes-Benz Forum

activ123 · #1 10-13-2009, 02:07 PM

I have a 1999 E300TD with about 170k on it. It has developed a squeak that is almost constant at lower speeds. Other characteristics:

- A bump will exacerbate it, but it sounds like something is wiggling
- It is not noticable at highway speeds or 35+ really
- I have replaced the ball joints and a bushing of which the name escapes me
- The Dealer said there was nothing noticably wrong (I mentioned the squeak when in there for something else)
- It is not clear whether this is a front end or rear end noise - I would bet front if I had to
- I cannot reproduce the sound by pushing down on any corner of the car
- Car has been serviced recently (don't ask ;-) I usually do it nmyself but it died 2 miles from the MB dealership so I got lazy (and now poor))
- New exhaust so it isn't that wiggling up under there. (although I did not put on new rubber mounts)

My guess is that it is either a motor mount or the transmission mount. Does this seem like a reasonable conclusion? Do these things usually need replacement? In other words, if I put new ones on and that it is not it, then can I still feel OK that I did not waste my $$$ (!)

Any other ideas?

Thanks in advance!

KarTek · #2 10-13-2009, 02:37 PM

Hard to say. It's probably not the mounts since they're squishy and rubbery - even when they fail.

All I can think of is some shielding on the brakes or suspension. Try having someone stand near a speed bump in a parking lot while you drive by at various speeds to try and hone in on the area of the car making the noise.

TMAllison · #3 10-13-2009, 02:50 PM

Have a friend sit in the back seat and listen with left then right windows down to narrow it down some.

Parrot of Doom · #4 10-13-2009, 05:09 PM

Noises are almost impossible to diagnose over the internet. Does it do it when its been raining?

I'd spray light oil into every nook and cranny, and that includes around the ARBs, ball joints, bushings, radiator mounts, etc.

You'll probably find it easier if you remove all three noise panels from the underside of the car, and then drive it.

lupin..the..3rd · #5 10-13-2009, 05:26 PM

Bad front sway bar end links are common on this model, but they make more of a knocking noise at low speed <35 mph. I wouldn't call it a squeak.

I'd get three friends in the car, roll down all the windows, and have them listen. At least that way you can determine whether it is coming from front or rear, and perhaps narrow it down to which corner of the car.

e300D97 · #6 10-14-2009, 03:44 PM

Mine was the upper control arm that squeaked.