PACIFICMAN

I replaced my "Supercharger" belt. When the belt broke I had to limp the car home (60 miles) it ran fine and the battery did not quit. After I changed the belt and started the can it ran but I had a pronounced "knocking" sound from the supercharger side of the motor. I turned off the engine and removed the belt, started the car, no knock. Any ideas?

RedGray

You drove the car for 60 miles when the serpentine belt broke? That belt also drives the water pump.


Take a video of the noise , and upload to youtube, or here.

It's unlikely that you did damage to the alternator by driving the car without the belt.
An idler pulley, or the tensioner puller could be bad.
Remove the belt, and turn everything by hand (but the crank ). Listen for noise, and feel for roughness.




Belt routing for an M111 engine:

PACIFICMAN

Thanks for your reply Red. I looked at your diagram. I suspect you have the 1.8L motor in your car, mine is the 2.3L, different belt routing(2 belts), no water pump in Supercharger loop. Having said that I have done as you suggest and spun/shook/listened to the un belted components. I find no apparent problems with any of them. I'm going to put the car on ramps to better access the Alternator. Has anyone HAD a noisy Supercharger or Alternator, rhythmic knocking sound?

RedGray

I do have an M271 engine.

But, I got the above diagram from autozone, and they said it was for an M111 engine (which I thought you had).

The alternator pulley has a clutch on it. That clutch may have been damaged when the belt broke?

C230 Sport Coup

No clutch on alt in 2002.
Perhaps the belt broke due to whatever is currently making the noise.
Well, you have supercharger, alternator, pullies and tensioner.
You can't make out the source of the noise?
Are they all turning? Perhaps turn by hand?
Any chance the belts are misrouted?

Diagram is in your owners manual.
Oh well, here it is....I'd say turn the individual parts by hand, then put the belt on and crank by hand, you need I think 24mm socket on front of crank. Then, maybe pull the fuel pump fuse, and crank the engine (that way you won't be running the engine and risk more damage, engine will briefly fire up and then shut down and just slowly crank, diagrams are here for fuse, fuel pump one is in the back on the left, I forget which one) try to see where the noise is coming from. How many miles on the engine?
Bad tensioner will make an obvious flapping noise when it's bad, you'll see it moving...
get a long scrwdriver, like 2-3 feet or socket extentions or any piece of metal long enough, just rest on the potentially offending item (being careful not to get caught in the belts), super charger or alt, and put your ear to the end, the offending one will be obvious.
And FYI fuse diagram is inside compartment next to drivers door, ie left,
on the side of the dash. Fuse puller is in the back...in case you decide to try what I suggested. Spare Fuses are with spare tire, well, at one point.
The only times I've seen belts break is if it's not installed correctly, or something seizes (happened on my girl's ML, the tensioner pulley froze). OR if you just never ever ever change it...the damn things last forever.