1997 Grand Prix GTP rattling noise

I have a 1997 Grand Prix GTP. When I put the car in drive, and it is sitting still, it makes a rattling noise. It does not do this when it is in park, or when the car is moving. Is this problem the coupler in the supercharger, or is it something else? I am a newbie to this site, and a proud new owner of a Grand Prix. I love all the information I am getting about my car. Thanks for your help

Welcome to AF!!

Try to narrow the location of where the noise is coming from. I would say, however, that the problem is the coupler in the supercharger. This is a common issue and not expensive to replace. There are several locations where you can purchase the coupler, including ZZ performance. Just make sure to use GM supercharger oil when you replace the oil after the replacement.

As Lynn suggested I'd go through the process of illiminaton first. To rule out the SC coupler remove the SC drive belt. You can operate without the SC connected for awhile.

Another problem with GTPs when in drive is a possible bad torque convertor flex plate or loose flex plate bolts which will cause a rattling sound. Another issue would be bad, worn out or misaligned engine mounts. I worked with a local GTP owner that had a rattling sound only drive and it turned out to be the exhaust system. The downpipe was touching the bottom of the chassis since he took someone's suggestion to loosen the front dog bone mounts to replace the rear bank spark plugs.

Thanks for the welcome. After a little more investigating, it seems as if the rattling noise gets worse when turning the steering wheel. It sounds to me like a bad power steering unit. Do you think it could be something else? If not, how hard is it to change the power steering unit on these cars.

Thanks again for the welcome, you all are very informative.

If not, how hard is it to change the power steering unit on these cars.

See tech procedure below.

Click here (http://www.automotiveforums.com/vbulletin/showthread.php?t=652596)

Also, make sure the noise is not caused by the main drive belt tensioner and pulley which is located by the power steering pump.