Hello, newbie and not a mechanic. My daughter has a 99 Regal that recently started making the can of marbles noise. Possible coupling issue. However, soon noticed small oil leak. Refilled. She came home from college today and said the noise suddenly stopped. My suspicion is it ran out of oil and ceased but the car is running fine. Belt is fine as well.
Can I just replace the nose cone, coupling? Or does it need to be dismanted to see damage? How long can I drive it like this? Any advice is good. Thanks.

What did you refill? Oil in engine block or SC'er oil?

Hard to diagnose without a noise....if it was the SC'er, the noise would not go away....

Possible catalyst breaking up?

SC oil. Took to mechanic and he said sc needed rebuilt. Shortly after the sc appeared to start leaking where nose snout meets the rest of the sc. Noise was the typical 'rocks' rolling around in nose cone. But now no noise at all and car runs as if no problems.

It'* only a nylon coupler inside. It'* possible that it self destructed and is no longer spinning the supercharger.

We've had members here in the past notice that the belt that drives the supercharger was broken after months of being not noticed. With it not running, your actually saving gas.

You can drive it without it running. The PCM will see less air coming in and automatically pull back on fueling. If you choose not to repair the */C, simply remove the belt and everything will be fine.

Mike I did not know that.....everyone I ever saw/heard, the noise did not go away....thanks for info.......

I know. I never heard of anyone saying the noise went away either. So, its purely speculation that the coupler disintegrated and maybe broke the studs off the hubs. I dunno.

On another note, don't be fooled that GM supercharger oil is the ONLY oil that can be put into them. $20 for 6oz of oil. GM has approved the used of Mobil 1 5w-30 SYNTHETIC oil. One quart will last a few */C oil changes.