Lower engine noise 2001 Impala

I am experiencing what appears to be a lower engine rattle on a 2001 Impala. This car has a 3.4 eninge with about 115K miles on it. I initially thought the noise was a bad tensioner which I replaced. This seemed to quiet the noise down some but the noise gets louder when the engine is placed under load from the A/C. As soon as you cut the A/C off, then you can barely hear the noise again. Has anyone else experienced this? I am going to take the car in and have it looked at but I wanted to get some advice prior to doing so. This way I hope to have some idea of what I am up against before I get an outrageous estimate for some work that I may not even need.

Welcome to AF. If you take the serp belt off see if the noise changes, from here we are handicapped in accurately diagnosing noises, this is an onsite check out only. Your concern about being " ripped off" needs to be addressed as well, find another shop.

I had the GM dealer check this noise out. It turned out to be a cracked flywheel. They charged me $110 to diagnois the problem and gave me a quote of $1210 to repair it. I brought the flywheel for $68, new sway bar bushings for $15 and transmission filter kit for $27. I had a GM certified mechanic from another dealership do all the labor for $500. He even rotated my tires for me.

Thanks for the post back, unusual problem for sure.