Grinding Noise at 2050 rpm

[davidson506]

Hi,

I have a 99 Grand Am SE V6 (automatic) and as I accelerate and hit 2050 rpm (on each gear) there is a grinding noise. As soon as it goes past 2050, the noise is gone. It has been occurring for about a year now, but there hasn't been any ill effects of this problem. I had the dealership look at when it first started, and they couldn't detect any problem - but it is definitely there. Any ideas what could be causing this?

Any help is appreciated.

[jpit]

Maybe just a loose heat shield that vibrates at whatever frequency 2050 rpm is at.

[davidson506]

I'm not so good with cars, could you maybe describe where I would find this heat shield and suggest how to fix the problem? I guess even if it can't be fixed, it's nice to know it's not something serious. Thanks for your help.

[jpit]

Heat shields protect your car from the heat of the exhaust. I have the quad 4 which is different than yours but just follow the line of the exhaust from your engine all the way to the rear of your car and check any of the shields to see if they are loose. Bolts will rust through the holes on the shields if you are in a high moisture/rust belt. I had this happen on my mazda last winter. It was a vibration noise that seemed to be only present at low rpm. I just put a large washer to span the larger hole made by the rust. This heat shield was on the exhaust manifold just as the exhaust exits the engine itself.