Hi,
I have a 2004 C240 4Matic (I had it for 3 yrs it has 145K) and if I turn the wheel maybe 80% to the left and bring it back to the right or have to make a right turn immediately my car makes a metal scraping noise. It also happens when I back the car up and turn the wheel to the left and then the right to straighten. Someone also described it as the sound a power drill or tools makes. When I am driving straight the car is fine. If I make a left turn only it doesnt make the noise. If I make a right turn only it doesnt make the noise. Only if I turn it left and then right. I took it to a mechanic shop and at first they couldnt duplicate the sound but when I took it to them the next day, they were able to hear it and duplicate it. According to them its my strut mounts. When I spoke to my friends who are mechanics (They only work on Hondas and such but not MB or BMW) they say that impossible b/c struts has nothing to do with turning the the car. Bad struts are only when you going over bumps and you hear a clunk sound. They think its my power steering pump. They have offered to change the strut mounts for me so I dont pay and its not the issue. The car hasnt made the sound in 4 days but now I when I turn the wheel it feels stiff and it gets a bit hard when making turns and it returns much slower than it used to. If its a sharp turn you feel some kind of air restricting it, if that make sense. I recently had my belts changed maybe 2 months ago so I know its not it and my power steering fluid reservoir is full so theres no leak. Its really driving me crazy b/c I dont want to drive it and it breaks down on me and its not repairable. Does it being my strut mounts make sense? Could it be the power steering pump? If I dont get anything fix what would be the next step, hearing the noise all the time? Ive taken the car to 3 mechanic and only 1 says they have found the issue and that seems iffy. Please help!

 

If you open the hood and watch the strut mounts as you turn the wheel they do move so they could be causing the issue. Have you done front shocks yet? If not I can't imagine they are in even ok shape so you should be doing them anyway. As for the noise it could be the front drive shafts, steering rack, tie rod ends and even ball joints. You should also have the PS fluid flushed with OEM/OES fluid at that high of millage.

 

@samaritrey- Thanks for responding. The mechanic did say that I needed front sway bar link (I think that's what they are called) and he said I should just get the struts changed since the mounts are on them. He didn't mention that anything was wrong with my tie rod and other things and I did ask him if it could be those things. I'm more concerned now that the car is not making the noise at all as of late and with my luck that just means its going to totally break down on me at any given moment. Could the steering wheel being stiff sometimes have something to do with the ps fluid needing flushing?

 

Stiff steering could be fluid or the rack itself but rack failures are not that common and at least on my car new fluid made the steering feel much better.