So I started getting the Diesel rattle from the engine a month or so ago. I've been driving it sparingly and got around to doing the tensioner plunger change today. So after I lost half my fingernail getting the plunger bolt off, I pulled it out and it came out extended. It also compressed and extended fairly smoothly. That's the first moment, when i thought, oh God, please don't be the supercharger.
I'm not the the most mechanical person, but I can follow a Bentley manual. Sooo, as I understand it, a dead plunger should be stuck shut, right? Before I can fire her back up though, i need to know it's safe to. Since my plunger came out extended, there was no problem putting the compressed plunger back in. All the directions I've seen require a pry bar or turning the crank to get their plunger back in or tension the chain correctly before starting up. Since my compressed plunger went right in, am I good to fire her up? Thanks as always.

 

ok then, what's the best way to check the SC? Stethoscope? Haven't seen any temp spikes yet.

This is an 03 MCS with 80k.

This is probably the most similar sound from the videos I've seen

 

That definitely sounds like your SC/Water pump end of your supercharger is going down for the count. I have the same model as you, 03 MCS, and my SC/water pump sounded like that at about the same mileage as yours. There are a few posts on here dealing with removal and replacement of the SC, water pump, hoses, thermostat and tensioner. I did my own, ordered all my parts from Way of Way Motor Works, and it took me 4 days. I would have finished much sooner, but I had just gotten back from a week of vacation in Florida and I did all the work outside in 100F+ heat and high humidity. So I took my time, followed all the advice I got from the guys here and used my Haynes manual. Good luck. Here are some of the links;

https://www.northamericanmotoring.co...night-diy.html

https://www.northamericanmotoring.co...at-change.html

https://www.northamericanmotoring.co...tensioner.html

 

Same here, '03 MCS and last year the diesel rattle sound become overbearing. Pulled the SC and waterpump gears were dry of oil , but the teeth still looked good. Just a week before mine, a guy at work also with an '03 MCS but stock pulley lost his SC WP gears the same way, but his teeth were too damaged to reuse.

Then, at MOTD, I found a company (http://www.imperialmini.com) that had developed a recharger product that replaces the waterpump gear plug. So I got one and it works great! I've done 3 oil flushes without having to disassemble anything .... and still no leaks detected