At about 65K miles my car started making a noise when the rpms dropped down to around the factory 750 rpms....Shortly after that noise started, my A/C compressor failed (The spokes are designed to break, but allow the pulley to spin free so you don't lose the belt...neat design to keep the car driving even if the A/C compressor locks up)...Paid to have the A/C fixed, but the car would still make that noise (like a bad throw-out bearing noise) It was the first time my mechanic had really heard that out of my style/year c230 and he initially diagnosed it as a possible throw out bearing issue....
25k miles later, the A/C comp goes again. My mechanic warrantied it parts and labor, which surprised me, as most will at least get some labor from you...
On Monday, it goes again at 110,000 miles.....This time, He's bound and determined to figure out what's causing this........

Turns out that the Alternator's sprag was bad and causing the belt to pulse which was obviously enough of a jerking to break the sprocket on the A/C...
He showed me how a good alternator's sprag will allow the pulley to turn the shaft only in one direction and then coast, like a bicycle. Well, mine wasn't coasting like it's supposed to and because it's such a large and heavy duty alternator, it acts like a gyroscope wanting to spin at a constant speed. .....I'm probably doing a terrible job of explaining this..
Bottom line:
using all parts bought from the dealership, he replaced the alternator at a cost of $329.00 + 1 hour labor, and replaced the A/C comp, drier, etc...at no charge....He also went ahead and did the "Service A", changed out the wiper blades, replaced a bad fog lamp bulb, changed the spark plugs, and front brake pads....Total bill was $780.43 + tax......This guy is probably the fairest mechanic I've ever dealt with.....Once I was out of my warranty, I went to him. He's a Master Tech and worked for MB as a tech trainer at their training facility before opening his own shop......

He's consistently been at least 50% less than the dealership for anything I've had done and he always uses MB OE parts.

Jerry's MB Service in Orlando.........I've used him for the past 60k miles and for everything required by MB, service wise. I highly recommend this guy (Jerry)
You guys in Central Florida...call him at 407-366-6499

 

That is very interesting.. I wonder how many other vehicles incorporate that same type of thing? (outside of mercedes I mean.)

 

I'm not sure.....None of the cars I have owned (Q45, 3 series, 337, Wrangler, etc...) have had an alternator with a pulley that would coast.....I was told that because there are variations in the speed of the belt, due it being a 4cyl, it made sense to design it this way.

I just wish I would have been a little more eager to remedy the noise a long time ago.....I'm just very busy with very little free time over the past two years......Plus, I sold my 337 about 6 months after buying the C230, which takes away my back-up transportation.

Scott

 

Scottisha thanks for posting this. It's always good to hear of good alternatives to the Stealerships in the central FL area. Will check him out.

 

Really good to know as i am about a hour from there,

 

Yeah.......He doesn't do a lot, if any, advertising...all his business is word-of-mouth...

I had the dealership in Maitland quote me on brakes (pads and rotors) and he was less than half for the same exact parts..In fact he orders from the Maitland dealership.....He's just one of a few honest and quality mechanics.
I can't praise him enough.

Scott