Okay, the code said gas cap and I replaced it. 90 miles later the light came on again; this time took it to a friends shop who has more precise scan tool than Autozone. Now, it says gas cap and also Misfire. So, I guess I need a tune up. We checked the supercharger oil and there appear to be metal shavings in it. Is the supercharger oil supposed to be brown like motor oil? Please advise. Thanks!

(Horrible thought: Is it possible some idiot previous owner put regular motor oil in the supercharger?)

The gas cap warning will go off whenever the gas cap isn't properly tightened after a fillup. If you've got some aftermarket thing on there, either dump it and get a GM replacement cap, or at least look up the correct cap number at AutoZone or someplace and just verify that you have the right one on your car.

Not sure what you mean by a "more precise" scan tool since all it'* doing is retrieving digital error codes and such from your on-board computer, but anyway, how many miles have you got on the car? What year is it? Does it look like it'* still got the original plugs, wires, etc?

The wires are the factory wires. My car has 80,000 miles on it. Spark plugs didn't look to good,either. What color is the super charger oil supposed to be?
(Horrible thought: Is it possible some idiot previous owner put regular motor oil in the supercharger?)

The gas cap warning will go off whenever the gas cap isn't properly tightened after a fillup. If you've got some aftermarket thing on there, either dump it and get a GM replacement cap, or at least look up the correct cap number at AutoZone or someplace and just verify that you have the right one on your car.

Not sure what you mean by a "more precise" scan tool since all it'* doing is retrieving digital error codes and such from your on-board computer, but anyway, how many miles have you got on the car? What year is it? Does it look like it'* still got the original plugs, wirer a fillup. If you've got some aftermarket thing on there, either dump it and get a GM replacement cap, or at least look up the correct cap number at AutoZone or someplace and just verify that you have the right one on your car.

Not sure what you mean by a "more precise" scan tool since all it'* doing is retrieving digital error codes and such from your on-board computer, but anyway, how many miles have you got on the car? What year is it? Does it look like it'* still got the original plugs, wires, etc?[/quote]

I just wandered into the next room and checked the '93 factory manual. Chapter 6G on the supercharger is pretty unhelpful about the oil, except to say that it'* synthetic, is enclosed in the supercharger, doesn't share oil with the rest of the engine, and is "sealed for life," along with various warnings about not opening the thing up.

You might want to check out http://www.bonnevilleclub.com/techinfo/?article=22 and see about changing that oil. At least afterwards you'll know what you've got in there.

Vic, sounds like you're due for a plug and wire change. Do you have a digital camera? I'd like to see a sample of that Supercharger oil on a white piece of paper. You still have the noise coming from the nosedrive, too, so maybe you should order that SC coupler and SC outlet gasket, and get ready to change it. Get the gasket from the dealer, and the oil too. You'll have the SC off, which will make the oil MUCH easier to drain.

My new coupler is due in any day, and I already have my new SC outlet gasket. I'll be able to walk you through it step by step.

For the time being, until we get this sorted out, go easy on the go pedal. If that is the wrong oil in there, it might be the cause of the nosedrive noise you're hearing.

Was the original gas-cap code cleared out the first time?

It is definitely time to change out the supercharger oil. Follow the procedure as in techinfo. Once changed, sometimes it will quiet the nose cone down, but I think I remember yours was likely a coupler, since it was rattling at idle only.

If it is a bad coupler, changing the oil won't fix the coupler problem, but it definitely needs to be done to save the bearings. Hopefully they aren't permanently damaged. You may already be looking at a new nose cone ($400). You can take the nose cone apart and replace pieces like the bearings and the coupler; I think you need a machine press.

Only use GM supercharger oil.

When the bearings are bad, it rattles at all speeds, not just idle.

Have you tried removing the supercharger drive belt and spinning the supercharger pulley by hand? You need to see how much play there is before the gears engage. Spin the pulley back and forth. If there is play, the coupler is bad.

If it is the coupler, get it from zzperformance and don't change your oil yet. It'll all leak out for the coupler change anyway

Good point. Don't sit on this problem very long.

Absolutely. If you HAVE to drive this thing, go easy on it. Keep it under 2500 rpms if you can. Under 2000 would be even better. You may not have damaged the nosedrive yet, but if that'* the wrong oil, or the right (but original) oil, we MIGHT save this in time!

Follow our advice. About half the reason I'm changing my coupler is for you!

(now I've GUILTED you into following our advice!)

Pretty slick, wasn't I Fuddy?