wickedwahine11

I just bought a 2007 CLK350 Cab yesterday, and I was driving with the top down today for the first time. I noticed a whistling type noise whenever I step on the brake -- not a screeching like the sound of brake pads wearing down, but more of a whistling noise. It also happens when I begin to accelerate from a standstill but is quite pronounced when I brake.

Has anyone else had this happen?

Yidney

If it happens when you step on the gas, then it probably is not brake related, although it could be. Where does it sound like it is coming from - the wheels or under the hood? Does it change in relation to engine speed? Does steering affect it at all? Does it do it every time or only sometimes? It it totally gone at a constant speed? Is it the same with hard and soft braking? Hard and slow accelaration? Experiment with all these things and you can start to narrow it down. Is it still under warranty?

wickedwahine11

Hi, thanks for the reply. No, I wish it was under MB warranty. I did just buy it at Carmax yesterday and so it has their 30 warranty. I wanted to return the car under their five day policy, but my spouse doesn't want to do so.

The whining seems to be coming from the rear wheels (as best we could tell driving it around tonight with the top down so we could hear it better). It does get higher pitched as I accelerate. I haven't noticed a difference between hard and soft braking but I will try that.

I'm actually going out of town for two weeks tomorrow and so it is going to drive me crazy during that time frame. I'm a typical girl, ignorant of most car mechanics, and online research had me thinking either a rear differential or rear wheel bearing sounds like what I need to tell the mechanic when I get home.

Sigh. I waited ten years for a CLK and now I'm stuck with this one -- I wanted to get a newer one with less miles, but I'm married to a cheapskate who didn't want the certified preowned one and opted for the cheaper Carmax one.