Odd rattling only when trans engaged

[opus]

I have one of the oddest situations going on with my 5. When shifting, and when decelerating while the transmission is engaged I have been getting this rattling noise. It comes and goes, and, here is the real twist, it is less frequent when someone, like the Mazda service shop manager, is sitting in the passenger seat!! It sounds as if it is coming from either the passenger footwell area or just behind the console. If I disengage the transmission , insert clutch move shifter to neutral, the noise automatically goes away!! The real issue here is that the transmission is located on the drivers side, so the service guy is saying it can't be the tranny. Any ideas would be appreciated.
Thanks,
Opus

 

[Robotazky]

Mounts and exhaust is where I would begin. Examine them the best you can, lifted, and let's go from there. It's going to be really hard to help you with "rattling noise" as the description, as you know. Do you notice a correlation between RPM and the noise?

 

[KBrian]

My 5, an 07' GT with a manual trans, also has a high-pitched buzz when decelerating as the rpms cross about 3000. Usually notice when in third gear as this keeps the revs around 3000 longer than in 2nd while slowing down. 4th and 5th I use the brakes to slow down and do not notice as much. I never shift down into 1st while moving.

The noise is not too loud or obtrusive, and could be an exhaust rattle from a shield or hanger. Dealer will investigate (warranty) at the next service.

 

[opus]

Thanks for the feedback guys. I hadn't thought about exhaust The dealer had the vehicle for about a week and couldn't find anything I'll ask them to take a look at the exhaust and I had mentioned engine mount before, but I don't think they looked there, so I'l have them check those too.