noise at idle and during acceleration - updated
I recently noticed a noise (noise is hard to describe) on my '92 SSE */c at idle and while accelerating.
I thought it was the supercharger because when I listened with a garden hose, the supercharger snout sounded noisy near the pulley, kinda like a rattling/grinding/slight squealing noise. Obviously, though, I wasn't able to drive the vehicle and listed under the hood at the same time to identify the cause of the noise while accelerating, so I went ahead and replaced the supercharger. But the noise is still present, and when listening with a garden hose it still sounds like the supercharger snout is noisy, but when listening with a mechanic'* stethoscope, the snout sounds normal but the upper belt tensioner sounds noisy.
Within the last year I've replaced the harmonic balancer, alternator, and all idler pulleys, and as I mentioned, I just replaced the supercharger too.
'99 Bonneville SLE, white, 112,000 miles
'02 Park Avenue Ultra, white diamond pearl, 88,000 miles