I am stomped. I have a 2005 Tribute, 2.3L. I have had this issue for a while now and would like to deal with it while I have some time off from work.

My Tribute has a rattling noise that can be heard coming from under the front left passenger area. The thing is it only happens when these three things are going on at the same time: the vehicle is in drive, the A/C is on and I have come to a complete stop. There is no rattling noise otherwise.

I originally thought it was the heat shield on the manifold, but that is tight. I checked the heat shield over the exhaust just to rule that out and its not that. I and my mechanic have looked while the vehicle was running, in park with the AC on and can hear it, but can not pinpoint the location. He thinks it maybe a pulley or the belt but he isn't 100% sure because for as loud as it sounds, you don't see anything rattling or shaking.

I need some ideas before I start changing out parts. Thanks.

 

You can take off the serpentine belt and try rotating pulleys individually to check for a bad bearing/internals associated with each pulley.
Another option is to get under the car while it's presenting the fault, take off the splash shield and stick a length of hose in your ear to limit the area you're listening to. Check around the trouble area. Should you need a hose, you can get one from a local car parts shop. They may look at you funny But an ear hose is an essential noise troubleshooting tool. 3 feet of 1/4" or smaller diameter should do the trick. Whatever fits comfortably for you and is convenient.

I only have experience with the 3.0, and that too is limited so I cant reference specific/common trouble areas/components.

 

Welcome to the forum