Noises problem
1998 Pontiac Grand Prix 6 cyl Front Wheel Drive Automatic 139522 miles
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One guy says it is coming from the water pump blades scraping the housing. Another says it sounds like a rist pin coming out. The noise stops at 1000 RPMs and above. Wouldn't the sound get louder at higher RPMs if it is a rist pin working out? The problem started after the supercharger belt snapped. I replaced the all the pulleys and the belt.

Isolate the problem by removing the belts and run the engine for a minute if no noise then check the pump and check the pulley
if you have the same noise after belts was removed then its most likely internal
you should have it check