[BNaylor]

First thing to do is isolate where the noise is coming from. It could be originating from the supercharger or SC drive belt system. It sounds like you may have bad snout bearings or a noisy SC tensioner/pulley. Remove the SC drive belt and spin the SC pulley by hand and listen for noise. Also, check the SC tensioner pulley.

If the SC oil is amber then it was probably changed out recently. It turns a dark color when mileage accumulates. I change my oil out annually just to be safe and check the level once a month. The bad rancid smell is normal.

You may be able to get replacement parts for your supercharger at places like ZZPerformance, Pulley Boys or even on EBay. Sometimes GM dealers will stock SC parts.