I have a 2001 Regal GS with 97k miles on it. I'm the original owner, and it has always been well maintained. Within the last 500 miles the supercharger started making a loud buzzing-whining noise. At first I thought I was puking the alternator, but replacing that didn't solve the problem. This morning I sucked out all the old oil from the sc and replaced with 2 full bottles of GM Supercharger Oil ($11 each -- ouch!). The sc still whines loudly. I also noticed that rolling on the revs in park the engine stumbles at 4000 rpm -- don't know if that'* related or what. Right now my concern is getting the blower to behave itself. I've read that there is a coupling in there that can go bad. The old oil came out kind of a dark honey color and was clean -- no chunks or filings visible.
Any ideas what could be going on here? I'm about to take off on an 1800 mile trip and would prefer to take the GS over my Astro, but if the sc is about to croak and leave me stranded I won't...
Thanks
Steve

Take a look at this write up, https://www.gmforum.com/normal-maintainence-138/change-supercharger-coupler-279064/ This will tell you if the coupler is the problem. You can also remove the SC belt and see if the noise is still there. running the engine with the belt off wont hurt anything, other then performance.

Thanks. The video sounded more like a clatter. My noise is a buzzing/whining sound. That'* why I thought at first it was my alternator. The alt on my Astro just puked about 3 months ago, and early in its death march it made a similar buzzy whining sound. With the alternator, it was the bearings that died, to the point that the case actually cracked when they fully seized. The guy at Advance Auto said he'd never seen anything like it before.
Back to my sc... is it possible that one or both of the bearings in the snout are going bad? And if that'* the case, how catastrophic will it be if they seize completely at, say, 75 miles an hour on the interstate? Would it strand me or just render the sc inoperable until I fix it?
Thanks
Steve

It'* possible the bearings are going. Pull the belt and check how free the pulley turns. If they do happen to seize up, it will shred the belt and that will be the end of it. You will loose power and perhaps get a SES light, but it wont hurt the engine. If you need a replacement supercharger I have 3 on the shelf all with good bearings and coupler. $125 shipped. Swapping them out is 2 gaskets, 2 coolant O rings, and two hours of time. Unless you live near one of our members that can swap it for you. Takes me about 75 mins.

Yeah doesnt take very long to swap one out..id just pull the belt if your not funded to fix it right now..realize tho it will still spin some as it is your intake....

Thanks Dan, I'll definitely keep that in mind. Doing it myself is no problem, except for the cold in my driveway. For the moment I'm going to leave it where it sits and I guess take the Astro to South Carolina tomorrow, much as I'd rather drive the GS. I don't want to risk it blowing up in the middle of BF Nowhere and stranding us on the side of the road.
Just out of curiosity, can the bearings be pressed out and replaced or are they swaged in place?
Steve

You will need a press to remove the old bearings and they also are pressed in.

I can do a press. The only remaining question, are these bearings readily available at the local AutoZone or Advance Auto or do I have to go through the dealer?
I just came in from checking, and there is some resistance to rotation of the pulley. There'* also a tiny amount of rotational play, then a slight clunk before I feel the impellers start to rotate. With the engine running I put my stethoscope on the snout, and the bearings at the pulley end sound like a pile of rocks.
Steve

Sounds like you need a full rebuild. I suggest a new coupler, both bearings, and a seal. The needle bearings are a bit more involved. You can get all the parts at intense racing or ZZ performance.

Well, I went out this morning and pulled the sc belt off in preparation for driving the car to South Carolina later today. Guess what? The whining noise was STILL THERE >:I
So, I got out the trusty stethoscope and touched it to the main belt tensioner pulley -- damn near went deaf it was so loud!
So I guess I need to replace the tensioner assembly, which is unfortunately almost a hundred bucks at Advance. Between that and having to drain the coolant to replace it, I guess I'm driving old Astro to SC. I'll tackle the Buick next week when I get back.
Dan, I may take you up on one of those $125 sc'*, though, just to have a spare for when the snout bearings give up on mine. As soon as funds allow...
Steve