strange noise while turning
 

Hey there! Ive been trying to search for this problem, but I seem to be having some problems with the search engine. Maybe someone can help me identify this problem. For the past 2 weeks my 85 300sd has been making this wierd "rubbing" sound when I turn right while the car is in motion. I have looked underneath the car to see that there is nothing rubbing on the tire with the steering wheel turned fully to the right. I did the same thing with the wheels turned completley the opposite way. Both times, nothig seems to be even close to rubbing with the tire. Upon further investigating as to what could be causing this, I have found that the noise only happens when the car is turning right and not while turning left. At one point I was able to duplicate the noise while the car was not moving, and I think its coming from the engine bay, but I cannot be certain. I feel it could be air in the powersteering system, but I have not done anything to the power steering system in over a year when I changed the fluid and fliter. Could this be the beginning signs of something ready to die??? Please advise!:(

Could be engine mounts, shock mounts, tire rubbing against guide rod or something, but probably wheel bearings. Any front end work done recently?

The only thing that has been done to the car in the front end was a brake job. Nothign out of the ordinary and it was fine after they were done.....and it was dne by a Mercedes specialy shop (Goldwing Motors) and that was about 2 months ago. The motor mounts dont seem to be damaged either. I repaired those when I first got the car 3 years ago

Does the noise change with braking? For example, wheel is turned to the right, making noise. Try applying the brakes. If the noise changes, I can almost guarantee a wheel bearing. Try it an post back. I will check later. Let's try to narrow down this problem.

wheel bearings, mine made the same sound, look up my user name and wheel bearings, you should see what I mean

Did they change the rotors when they did the brake job? If so, you may just need to tighten the hub up. Recommended to recheck torque after a couple of months (when rotors are replaced, wheel bearings must be repacked).

I had the wheel bearings checked while doing the brake job and the guy told me they were fine and had them repacked. Noise does nto change while braking or not....only while turning. It does not matter if you brake or not

The rotors were changed. That could very well be the culprit....Ill look into that

If it doesn't change with braking action, it may be a ball joint or tie rod end. Also, as I mentioned earlier, the hub may need tightened.

That sure does sound like wheel bearings, particularly the ones on the driver's side. The shop may have undertorqued the nut, as MattBelliveau suggested, or they could easily have overtorqued it. That'll do a great job of quickly killing wheel bearings. Raise the front of the car, check for play in the front wheels, then spin them and see if they make a grinding sound. If so, I'd say your shop owes you some wheel bearings.

As for the power steering fluid, I don't think it's possible for air to get trapped in the system. Once the wheels have been turned back and forth a few times air will work it's way up to the reservoir. As long as the fluid is filled to the line and the power steering pump and steering gear are good, everything will be nice and quiet.

i concurr wheel bearings is what i would suspect first if visual inspection reveals nothing rubbing.

tom w

Guys Thanks so much....I will look into this, as I sure do not want a wheel bearing going on me on the freeway! Thanks for all your input, I will lift the car and check it out tomorrow!

I had a similar problem with my '75 240 D (W115). It turned out to be comming from the rear. The ball joint that holds the sway bar to the wheel backing plate had broken so that when I turned a corner (mine was to the left) the sway bar would ride up and rub. I don't know if your car being newer has a similar arraingement, but it is a quick check.
Scotty

Scotty im not sure if I do have that setup but I will sure take a look. Thanks for your help

Such noises can be so illusive !
 

If these suspension parts are suspect, you might as well include the upper control arm too... the one on the side that the noise is most noticed!
But usually a control arm gone bad makes "klunk"ing noises!

I've seen where there are amplified microphones used to help pin down the source of such undercarriage noises. If I could find such a system that had two microphones and stero headset, I think I would jump on it in a jiffy! The mono type I saw advertised at www.**************.Com. Anyone know of a 2 mic/stero rig?

Sam