i get a loose rattely noise at idle or when in park and the brakes on.... on my 94 ssei... whats that?

Possiblities are:
Harmonic balancer
Water pump
Power steering pump
Supercharger coupler

My LOUD rattle that started on Friday at idle and with brakes is the harmonic balancer. With the engine idling, look with a flashlight. Does the crank pulley seen to wobble a little, then steady out if someone gies it a little gas? Can you grap the SC pulley and trun it a little so that the outer portion of the crank pulley turns a little without the center turning? Those are good signs of a bad balancer.

hmmm how much do those cost and are hey neccesary to fix, it dosent bother me much...

Possiblities are:
Harmonic balancer - $105 with shipping from GMPD
Water pump - $25 to 30 depending where you get it
Power steering pump - $90 ish + core
Supercharger coupler - $25 from ZZP

At some point, any of these would become neccesary to fix.

I would suggest getting a mechanics stethescope for $10 to start with. Narrow the problem down to the root cause, then buy whatever part you need.

hey guys you forgot one thing

ever think about maybe its a heat sheild???

I didn't say mine were the only possibilities.

Loose heatshields are pretty uncommon. Most are riveted, which doesn't make them prone to loosening, unless they're bent and rubbing/vibrating on something. You'd usually hear that on accelleration, not at idle.

I just bought a harmonic balancer from GMPD for a 94 SSEi and it was $154 with shipping. I just got a SC coupler from zzperformance and it was about $45 with shipping.

Typically, if it'* the harmonic balancer, you'd be able to see the inner portion separated from the outer. Also, it would make noise other than at idle. The SC coupler just makes noise at idle.

I would say both jobs are for people decent with working on cars. They aren't difficult but can be a pain. Also, if you put ona new coupler there are other expenses. You need gaskets, seals, SC oil, antifreeze. While you have it apart, you may as well grease teh SC bearings, and clean out the throttle body and SC housing too. Since you have to take the belts off to replace the harmonic balancer, it may be a good time to change those too.

I took some time to clean everything really well, including my injectors, throttle body, SC housing, and put on new vacuum lines. I can definately tell it flows better and I get better throttle response.