It has finally warmed up here a bit in chicago and I was driving with my window down for the first time in a while.
This noise must have developed over the past few months because it was not apparent before winter. The car has 80k, a history of regular maintenance, and generally well maintained.
There are two separate sounds I am hearing. There is a kinda lower grinding sound, accompanied by a higher tick.

Please take a look at my video and let me know what you think.

 

Ah the old 'coffee grinder' that's the supercharger lobes meshing because your coupler/bearings are shot.
Time to look for a rebuilder or get the kit and do it yourself.

 

+1 on supercharger noise being a worn bearing in the snout.

To confirm the diagnosis, remove the serpentine supercharger drive belt and see if the noise disappears.

 

Have the secondary timing chain tensioners been inspected for signs of wear or cracking?

 

secondary tensioners were replaced under the previous owner.

 

Did the PO also replace the primary timing chains, guides and tensioners?

 

No just the secondaries

 

Given the age of the vehicle, the primary timing chains and associated parts can fail, especially the guides with pieces ending up in the sump.

 

Remove the supercharger belt and see if all the noises go away. You can drive it without that S/C belt just an FYI. You want to at least isolate that ticking noise but you have to quiet it up a bit.

 

+1 pull the SC belt!!

Before you even bother starting the car after pulling the belt, spin the blower pulley by hand, back and forth, and see how it feels. If it feels a bit "springy" with a free lash of maybe 10 degrees or so, it's not an obvious coupler failure. If you get about 1/4 turn before you feel a hard clunk and the SC engages, then your coupler is toast.

If you end up pulling the SC and rebuilding the snout yourself, make sure you replace the valley hoses while you're in there. Even if they look good, just replace them to be safe.

 

Weather should be in the 40s this week, so I'll try pulling the belt this week and report back. Thanks!

 

I was able to pull the belt off today. With spinning the pulley by hand, there was no obvious play up or down or in and out. When spinning the pulley, I could SLIGHTLY hear two parts rubbing together, but the action was more or less smooth. There was no obvious clunking when turning the pulley. With the car started, it sounded identical to having the belt attached. Whats the next place to look for source of noise, primary chain tensioners?

 

slap some new ratcheting tensioners with guides

 

Is this kit OK, https://www.ebay.com/itm/172554896701 or should I get the Chris kit for $100 more? What else should I replace while i'm at it? Water pump?

 

It could also be the supercharger coupler...you will have to remove the front snout to confirm or reject my theory

stock:

https://www.ebay.ca/itm/115435017153...hoCd-wQAvD_BwE

vs aftermarket:

https://www.ebay.ca/itm/171730479320...Bk9SR4yGyaXOYQ

one has springs that introduce play so to absorb the variations that occur during belt speed changes, and the other (aftermarket) has no free play

some relevant stuff with GM superchargers:
https://www.cadillacforums.com/threa....254244/page-7

https://static.nhtsa.gov/odi/tsbs/20...37217-9999.pdf

 

I guess the next step would be to remove the main drive belt and see if that nets you anything. It would have to be removed to pull the timing cover so it’s one step closer. It’s worth a try.

 

To me noise is metallic. You can take alternator belt off an try again. But I bet that the fault is in timing chaing and chain is grinding metal parts already.

 

I am with Vauxi, by the way it sounds.

 

you called the shop i work at…

does the thing still run? we’ve done timing sets before