curewins

I have a 2006 c55 amg that I brought into Mercedes Benz because it died out when I was driving. When the dealership checked out the car, they said it was dying because of a solenoid that needed to be replaced, and quoted me around $700 for parts and labor on that.

Now, I've had the car for a little more than a year now, and it's made a whining noise from the engine compartment ever since I bought it. The noise is pretty high pitched, and it occurs from the second the car is started, growing more high in pitch as I increase the RPMs.

The mechanic at MB told me that the whining noise is unusually loud, that it's the result of a bad pulley inside the A/C compressor, and quoted me around $1800 to fix it. He also told me if I didn't take care of it now it could become a $3000-$4000 fix down the road.

I've spent quite a bit of time on this board, and I've found lots of people referencing a "whining" noise coming from their c55, but I've gotten mixed explanations, very few of which describe the A/C pulley as the culprit.

Does this sound right to you guys?

Viper98912

Could be a/c, power steering, or idler pulley. On mine it was the idler pulley (about $15), and I think the other two make some noise but not enough where I can hear it on the stethoscope. The idler pulley definitely sounded like a bag of rocks with the stetho.

curewins

Yeah, I've heard that it can be the idler pulley as well. Anyways, I did have the technician go ahead and do the work on the a/c compressor, and the whine is 100% gone. Ahhhh finally no more whining from my c55.

I've heard a lot of recordings of c55s that make a similar sound, so for anyone with a c55 who might be experiencing a whine that grows in pitch with the rpms, that pulley inside the a/c compressor could definitely be the culprit.

thanks!

91RS

We'd really have to hear the noise to tell you if it's normal or not. All 55 AMGs make cold start whining noises from the AIR pump and oil pump.

GTibunny8v

$1800 to replace the A/C pulley is crazy. The pulley cost around $350 list and its 2 hours labor iirc to replace it. I do them all the time and it takes 45 min on a 4 matic car and 20 min on the C55.

curewins

I'm not sure exactly what it was they replaced. The dealer told me that "a pulley inside the A/C compressor" was causing the problem. I'm not an expert on the subject, so I honestly have no idea what they're specifically talking about. Maybe it was just the pulley that needed to be replaced, and I simply got ripped off. Maybe it was more than just the part you're citing or a different part all together. Like I said, I'm not an expert so I don't know.

All I know is whatever they did made the whining sound go away entirely. At high rpms it's ridiculous how much quieter it is inside the car, and I can hear the engine a lot more clearly now.