AC Compressor Making Noise - C240
 

Greetings -

A month ago I bought (on impulse) a 2004 C240 sedan. This is my first experience with an upscale vehicle, let alone an MB. After 40 years of driving crappy little econo-boxes, I figured I owe it to myself to drive something nice before I die.

To make a long story short - I bought this vehicle from a used car dealer. I took it to an MB dealership (after I bought it) to have it checked out. One of the things I noticed was a whining noise coming from the left side of the engine bay. Not too bad - barely noticeable at idle - but getting louder with increasing RPM's. The dealer confirmed that it is in fact the AC compressor making the noise. And this they could remedy for approximately $1800; 900 dollars for the compressor, drier and pressure switch, and the balance for labor and R134 refrigerant.

There is an internet vendor who sells the brand new OEM compressor for the C240 for $525 (not rebuilt, but the exact same item that is installed at the factory - or so it is claimed). With a guarantee.

I am wondering if I should buy this compressor and have it installed at an independent shop that does AC work and save a few hundred dollars.

The under-hood environment of this vehicle is a very intimidating place! It sure looks to me that if a technician does not know his way around, he could end up breaking things in the process of assembly and/or disassembly.
Things other than the system he is working on.

Anybody have an opinion on the independent shop/dealership issue - not just for AC but for any other system repairs?

Willie R.

I'm not real familiar with the newer MB models, but if the compressor has a clutch it may be the bearing in the clutch. If that's the case you can remove the clutch and put a new bearing in or you can replace the clutch itself which would come with a bearing already pressed into the clutch assembly. On the 124 and 163 chassis MBs I've done this job without removing the compressor.

Find out if it's the clutch or the compressor.

Willie, you came to the right place. The Indy vs. Dealer issue has been kicked around here on the Forum for quite a while. IMHO, independant shops are great for general repair work. Every so often though, you'll need someone with more experience working on later model MB's, and a dealer will be your best bet. The tough part is knowing how to decide which choice to make. That's where the Shop Forum comes in very handy.

Concerning you A/C problem, I believe a qualified indy is your best bet.

Just adding my 2 cents here - typically if the clutch is the problem the noise will mostly be apparent when the A/C compressor is not engaged. Once it is engaged (clutch closed) the whole clutch assembly, including the outer pulley surface, will rotate with the compressor hub, so it should not be making any noise. If the compressor makes noise while it is engaged, most likely the actual compressor is on its way out.