My 2001 s2k makes a rattling noise. No one seems to know what it is and I really don't want to pay $100 for a dealer to tell me they don't know either. Here are details:
1. Rattle coming from just behind engine. Almost like it is from right below the radio coming into the cabin.
2. Sounds like metal rattling around in a sauce pan. Less like a heat shield and more like a bearing wearing out...
3. Rattles when engine is reving, in or out of gear. Rolling or not. It is louder when it is rolling. When you take foot off gas, and coast in or out of gear, it quiets to point where is is hard to hear...
4. IT RATTLES LOUDER when turn right, and not at all when turning left!!! THat is the very strange part.
5. After you drive for 45 minutes to an hour, it gets MUCH louder and you can here it at idle, and you can feel a slight vibration in the gas pedal...
6. I don't think it's inside the engine because it sounds smooth and fine, and revs hard all the way up. HELP - It is driving me nutz!!

 

Sounds to me like muffler bearings. If you have higher mileage on the 2001 it is likely time to replace them.

Have you had a friend rev the car after driving it a while while you poke around looking for the noise?

 

Hmm, sounds similar to this one time a friend of mine had an oil cap stuck somewhere near the firewall. Sound clip would help.

 

I had oil changed by a local shop and they forgot to put cap back on. (never again) I thought of this but really can't seem to find the cap. Do you know where exactly your friend found it, or how the heck he reached in there to get it. This would be extremely helpful. Thanks!

 

I don't recall exactly, but I'll try to find out for ya.

 

Julie is talking about me. It sounds like you have a oil cap stuck between the firewall & your tranny. Use a wire coat hanger to get it out. Its really hard to see but if you look from the driver side against the firewall I would bet you will see it.

 

I'll give it a shot. Use the wire from above, looking down into engine bay from drivers side? Or from under the car? Can you losen it to fall through or do you trying to hook it and pull it out.. Sorry for all the questions, I'm praying this works.. Thanks a million...