Hi Everyone,

I just had a very scary thing happen this evening that I'm hoping you all can help me figure out.

This afternoon when I started my ML350 (2007) up, it was making a loud sputtering sound that increased in frequency of sputters when I pressed on the gas and slowed when I came to a stop. I had taken it to the dealership a couple of weeks ago for its A-service and because it was making a whining sound. They explained that my power steering pump would eventually need to be replaced in a couple of years and that the whining was probably just air in the line. The sound today was different so I thought I'd take back in on Monday to figure it out. But I needed to be somewhere so I continued to drive it.

After taking care of my errands, I headed home and as I was getting onto the freeway, I heard something sound like it broke free and tumbled out of my car and the sputtering noise quit. At first I thought that maybe I'd had something stuck under the hood (heaven forbid a cat!) and it fell out resulting in the noise going away. But after I exited the freeway and headed to my apartment, the steering became very very difficult.

I managed to steer it slowly into a parking space. Then the red battery icon lit up. The steering is so difficult, I cannot drive it but the gas and breaks work fine. The engine sounded fine at this point as well. The battery is new, it was replaced less than 6 months ago, so I know that's not the issue. Can anyone tell me what happened?

Thank you!!

El

 

Have you open the hood to look?

 

Since I got in late last night, I could not see what was happening under the hood. Had I looked prior to driving it yesterday I would not have known what I was looking at or for. I'm mechanically inclined to a point. But I am not very strong (I'm a small woman) and don't have any special tools.

After having my morning coffee and researching potential issues online, I went out to look under the hood. Found my serpentine belt, which looks brand new, lying on the floor of my engine compartment as well as some pulley pieces. The belt tensioner looks fine, but one of the idler pulleys and the pulley on the air conditioner compressor are both totally blown. See the attached pictures.

I think I can easily replace the idler pulley, but my question for you all is whether the pulley on the air conditioner compressor can be replaced without replacing the entire part (which costs roughly $300 on partsgeek). Has anyone just replaced the pulley on this part before? I'd love some guidance.

Thanks in advance for your help!
El

EDIT: Forgot to mention that all of the pulleys (except for the air conditioner compressor pulley which is gone and the crankshaft pulley because the car is in park) spin freely in both directions. What could be the cause of the destruction of these two pulleys??

 

Hard to say what failed first, but the idlers are fairly easy to replace.
I am not sure about the AC pulley.


I would be tempte3d to replace the tensioner at the same time just to be safe (and put on a new belt.)
I would have a serious talk with dealership because I bet whatever was making the noise is what failed, and they should have caught it.

 

So I towed the car to my mechanic, Strictly Mercedes Benz in Seattle, and their diagnosis is the same as mine. The mechanic explained that my a/c compressor is blown and potentially seized causing the whole mess. So they are going to replace the a/c compressor and the idler pulley, then clean out the other pulleys because they are covered in pieces of the shredded belt. They also have to evacuate and charge the a/c compressor. The grand total is roughly $1,500. From my online research, this seems fair since others have posted that dealerships want about $2,500 for the same work. Any thoughts on whether I'm getting ripped off or not?

Thanks!
El

 

idlers and tensioners are only about $200 extra (doing them yourself)
See what the dealer will charge to toss then in. Really very little extra work.