Supercharged 2011 marble noise after SC oil change

Howdy everyone. New to TW membership and wasn’t able to find anything that addressed this specific scenario, so here goes.

I purchased the my ‘11 DCSB with the supercharged 4.0 in December. I’m the second owner, the title is clean, and the truck has just under 113k.

The long short is that I removed the cone and replaced the coupler, did the SC oil change with GM oil, resealed the cone and installed a new SC belt all at the same time I replaced spark plugs. Plugs showed normal wear and the SC oil was fine but dirty (sorry, no pics). I’ve noticed since that low end power is up a little-probably plugs-and it idles a bit more smoothly. However, after all of this was done I found that the truck sounded like I left marbles on top of the intake and they’re now rattling around when I’m idling. The noise goes away, as others have indicated in other threads, above idle and when I’m into the boost.

I’ve read elsewhere that the marble-like noise is “normal”, but I can’t get on board with such a marked difference in engine noise/note at idle. Walk with me, if you will through the possibilities:

1. Coupler installed improperly? New style (no spring) coupler isn’t directional and fit snuggly.

2. SC oil was overdue (112k) and change in viscosity caused enough variance internally so as to start making noise. This is just how the blown Tacoma’s sound.

3. SC tolerances, for some reason, are out of spec and the SC’s internals need rebuilt.

4. Oil, belt, coupler and plugs functioning as designed make obvious a previously existing condition with the engine (possible piston or wrist pin).

The question: has anyone experienced this scenario or something close to it and resolved the issue? Any other potential issues that you’ve experienced I’ve not thought or or read about elsewhere?

I have not pulled the SC belt or unplugged coil packs for individual cylinders or “put ear’s on” pulleys to listen for a bad idler or pulley for the SC. Thanks in advance!

 

I wonder if this is a side effect of the solid coupler versus the spring drive.

 

If you have 120k miles on that supercharger it needs a rebuild. Generally they need rebuilds from 80-100k.

 

Welcome to TW!

You'll get some knowledgeable answers and great advice if you go to the Performance/Tuning subforum and post there or ask in this thread.

There will be some sound akin to what you've described. It shouldn't sound like a racket though. May sound silly, but did you use enough oil?

 

The truck was cold when I did the refill-I assume since it ran out that it was full, but will likely check it again, as I have 1-1.75 oz. leftover. I’ll try posting to the tuning sub and see what that drums up.

Something else that seems more relevant now is that when the truck is cold and in gear at a particular low speed rev range (second gear @ ~2100 rpm) there is a loud rattling sound coming from the engine bay. I read into this when I first got the truck, as I was concerned there may be a bearing or pulley problem.