This can be a HB. That'* where your timing signal comes from. Check it carefully. It shouldn't move at all.

Billha, did you turn your SC by hand? If the needle bearings on the other end of the rotors fail, they can transmit noise to the Nosedrive. Did you replace those bearings when you rebuilt your ND?

No, it'* not the harmonic balancer. That was already replaced not long ago.

I've replaced every pulley with bearings on this car. I haven't spun each pulley by hand recently, but if I have time, I might try that.

I thought about the water pump as a possibility, too, because it has roughly 75,000 miles on it, but when listening with a stethoscope or piece of hose at idle, it sounds quiet.

This supercharger only has a rebuilt nose - new bearings, oil seal, oem coupler, and */c oil. The rest of the supercharger hasn't been touched, and this unit was pulled from my '93 at around 125,000 miles due to the infamous rattling noise at idle and a leaking nose oil seal. The fact that the rest of this supercharger has lots of miles was what caused me to post the survey about supercharger repairs/longevity.

It'* just so frustrating that I spent several hours replacing the prior supercharger that had roughly 75,000 miles on it, with this one, but the noise is still present, and maybe worse than before...and even though the current one has a new oil seal, the oil seal is leaking intermittently so there'* yet another issue to deal with.

Your ? about supercharger longevity. Look at my SSEi. The only repairs I have had to put into it are fuel pump, water pump, and idler pullies. All after 220,000 miles. SC is still original, even coupler.

Billha, break out the stethescope again, and try to determine which END of the SC it might be louder on. But I also like the idea of spinning each pulley by hand.

Both ends of the supercharger sound noisy, but they make slightly different noises. The noise on the intake side sounds loudest near the throttle body itself.

So the question is, should I keep using this supercharger indefinitely, or should I reinstall the one that had 75,000 miles on it and also made noise, or do I install a brand new unit that'* been sitting in my garage waiting for a rainy day?

You don't feel anything when turnig the pulley on the SC?

Nope, it feels tight and doesn't seem to make noise when turning the pulley by hand.

I think we should dig deeper before swapping the SC out.

Bill, how about running at idle from a cold start for a few minutes of troubleshooting WITHOUT the SC/WP belt?

And we stress very few minutes. As you will be without water pump and any cooling at all.