Buick Down! Help!

[brannynjanie]

89 Riviera-Rattling from bottom of engine while idling, stops when you accelerate. Thought it was the power steering pump, replaced it, didnt fix our problem. Now im leaning toward replacing the harmonic balancer. Took off the serpentine belt and the rattling stops. Any thoughts? Does this sound right to you guys? im no mechanic any suggestions would be helpful. Ideally id like to find some sort of guide or walk thru or something like that. Thanks.

 

[redmondjp]

Well, since the serpentine belt runs every single power accessory, the next thing to do is to, with the engine off, try spinning every pulley driven by the belt to see if there are any abnormal noises. Everything you spin should turn freely and smoothly with no odd noises.

My hunch? You have a bearing going out, either in the water pump or in the A/C compressor clutch. When my compressor clutch bearing started to go, it did exactly as you describe (noise went away when RPMs increased).

 

[Cadillac_AL]

If all the other pulleys turn freely then it probably is the balancer