supercharger question

[OffRoadSonoma]

I have a 1996 riviera 3.8l supercharged. Are there different supchargers they used on these motors or only one and how do I know which one I have?

[BNaylor]

For the Series II 3800 Vin "1" GM used the Eaton M90 supercharger. None other that I know of. The pic is an Eaton M90 Gen3.

[96riviera18]

correct, the m90 is for the L67 or series II 3800.(which you have, provided its a 96 s/c riviera) there is also the Eaton M112 for the L32 -new series III 3800 (like in the new impalas), that is not found in any stock riviera. however in 95 the supercharged riviera's had a less powerful engine with a different eaton supercharger. there is also the M45 (like in kompressor benz) and the M62 like on the new SS cobalt. the M112 is the largest and most powerful but the M90 is not far behind.

[BNaylor]

Originally Posted by 96riviera18

correct, the m90 is for the L67 or series II 3800.(which you have, provided its a 96 s/c riviera) there is also the Eaton M112 for the L32 -new series III 3800 (like in the new impalas), that is not found in any stock riviera. however in 95 the supercharged riviera's had a less powerful engine with a different eaton supercharger. there is also the M45 (like in kompressor benz) and the M62 like on the new SS cobalt. the M112 is the largest and most powerful but the M90 is not far behind.

Are you 100% sure the L32 SIII 3800 has the M112? That is typically used on V8 engines. The last time I checked the L32 versions of the Grand Prix and Impala SS use an Eaton M90 Gen5 blower. Also, blown Series I 3800 use the M62.

The issue here was the '96 Riviera. Keep the discussions on target.

[96riviera18]

my mistake, your right its just an updated version of the M90. it was late

[OffRoadSonoma]

Thanks for clearing that up. So here's the problem I have. The supercharge is kinda loud. I've heard other superchargers and mine is a lot louder. It's not really a screach like a bearing but it's not a rattle like the coupler. This is the first supercharged car I've owned so I don't know much. I've read some other posts on how to replace the coupler but I'm not sure if that is the problem. So are there any company's out there that offer rebuild kits or just replacement bearings or what do you think needs replaced? Also, I just bought the car so I don't know how often the s/c oil has been changed but it is full and kinda amber colored but does smell kinda bad. But the car has 126k miles so I don't know what kinda maintanance is reqiured at this point.

[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.