» View Question

mattintn87 4/19/2015

2001 Pontiac Sunfire SE 4 Cyl 2.20L


Loose Marbles/Rattling near Alternator & Serpentine Belt

Yesterday, I went to the store and everything was fine. When I came back out and started the car, it started making a rattling noise similar to dragging tin cans across pavement. It does this as soon as I start the engine and continues until I turn it off. It's roughly the same when idling, and driving at a consistent speed, but it does seem to be more intense when accelerating. The noise is LOUD. I've looked under the hood while the engine was running and I'm about 95% sure the noise is coming from the area around the alternator, serpentine belt, and coolant reservoir.
There are 162,000 miles on this vehicle. The temp was around 70F (21C) when the noise started (I've operated this vehicle in temps as low as 0F/-17C and high as 110F/43C and it's never done this before). The check engine light is NOT on. My parking brake light has been on for two years, but I've had two mechanics tell me that my brakes and brake fluid are fine so "they don't know."

1 Answer


Jimm 4/19/2015

Several possibilities; worn alternator bearing, worn idler pulley bearing,belt tensioner is worn / faulty.

Check these on-line vendors for the replacement parts; www.autopartswarehouse.com, www.RockAuto.com, www.partsgeek.com, to list only a few. The belt drive idler pulley is around $8.00 for your vehicle.


Answer this question

( characters left)

Follow Question

what's this?