wfooshee

The 2003 S55 I bought last year had known issues, primarily some minor front-end damage and the general result of unmaintained ABC. I've replaced the accumulators and made the car safe to drive, although ABC still needs work, like valve body rebuild and strut rebuild, probably. Not what I'm here for, now, though.

Another issue was lack of expected performance. I mean, yeah it was kinda quick, but not SUPERCHARGED quick, y'know? Found out why a couple of weeks ago.

The car threw the accessory belt, which of course is behind the supercharger belt. On removing the supercharger belt I found the pulley broken at two of the V-grooves, and not connected to the supercharger at all; the pulley was just riding the bearing but not driving the Kompressor.





Found a salvage replacement on eBay for two and a half Franklins and got that installed. Before doing so I made sure the supercharger turned freely, which it does. There was the obvious concern of why the pulley was sheared like that. I'm thinking (hoping) a replacement bearing was forced into it none too smoothly, causing the break. The "new" pulley came with the bearing, which turns smoothly, and went on easily once started and gently tapped to get it straight enough to slide onto the supercharger shaft.

NOW the car pulls like I expected. I've engaged traction control on dry pavement, which it never did before. Slowpokes on two-lane roads are no issue any more, either!

But...

I can hear the supercharger pulley clutch engage with a little squeak as I move out from stops, and this concerns me. I've never had a supercharged car before, much less an AMG, so I don't know if that's normal, or if it's something I should worry about and look into. Overthinking, worrying too much, paranoid about it, or is the pulley eventually going to shear again?

I've not done the supercharger oil change, (suck out the old, drip in the new) but would have no problem doing so if the collective feels that it's warranted.

maw1124

Yes, change the fluid, absolutely! Also search for “chirp” — known issue, although now I cannot remember if it was a pulley or a belt. GL

I would start with tensioner pulley and belt, right after the fluid. Not sure about that salvage supercharger pulley. But I’ve not had to replace mine (fluid, tensioner and belts regularly though which probably helps) so maybe they don’t go if maintained properly.

maw

DRTYLNDY

My previous 2003 S55 which my Dad actually still drives today and has about 150k miles now has always chirped when the SC engages. I did change the oil in the SC years ago and it was smelly and disgusting.
I would not worry about it.
Johan

wfooshee

I'm not too worried about the replacement pulley's bearing. I've seen Youtube videos of bad bearings and the noise they make, and what they look like when they're off the car, and this one has none of that. My concern was the chirp, which seems to be normal.

GrepAwk

‘Twas the very first complaint I brought to the dealer when new in 2003. They futzed around replacing the belt and finally I told them leave it alone. “Normal operation.” Search the archives.

The chirp happens when the revs hit 1.5k RPM and your accelerator pedal is calling for more power, so the SC gets a signal from ECM to push the clutch out on the SC to grab on to the free-wheeling pulley. When the clutch surface hits the spinning pully, it slips a bit until the SC starts spinning to match the RPMs. This usually takes less than 1/10th of a second and the slipping metal-on-metal is the source of the chirp. I don’t think it’s belt squeak, but it does wear the belt.

The SC clutch/pulley/bearing was derived from automotive air conditioner systems. Ever hear an AC chirp when the pump kicks in?