Thread: Loud rattling noise coming from belt area

I had the alternator run on a tester at Advance Auto. It didn't make any noise whatsoever. I guess that leaves me with the A/C compressor. Is there a way to distinguish between a problem with the air gap between the clutch hub assembly and the clutch rotor and a problem with a bearing?

Originally Posted by jpearsall187

I had the alternator run on a tester at Advance Auto. It didn't make any noise whatsoever. I guess that leaves me with the A/C compressor. Is there a way to distinguish between a problem with the air gap between the clutch hub assembly and the clutch rotor and a problem with a bearing?

Sure. If the air gap is too small, it will make a light metal scraping sound when the AC is off. And you should be able to replicate it when turning it by hand. And you will probably see metal shavings clinging to the compressor clutch.

If the bearing is bad, it will feel gritty when you turn it by hand. And/or wobble.