So about a week ago my engine was replaced under warranty by Mazda. They did the full engine assembly, gasket set, ignition coils, wires, plugs, and a new cat (also under warranty). Pretty sweet deal to say the least.

However, since that point the car has made this weird metallic clink periodically. I first noticed it when moving from a dead stop with my windows down in traffic where people were next to me and the sound bounced back at me really well. Since then I've noticed it several other times. I've heard it when approaching a stop with the car out of gear, and also one day while parked next to a car and revved the engine a bit. It sounds (to me) as if it were coming from the mid to rear section of the car. The best way I could describe it is if you were to roll a small nut across a piece of sheet metal.

Any ideas what could be the culprit here? Tranny? Diff? Engine?

For reference it's a 2007 GT MT with 78,500 miles on it.

 

Sounds like a misaligned PPF (powerplant frame). could be anything though, it would need to be properly diagnosed.

 

See if it happens when you hit mild bumps or cracks in the pavement. The rear heat shield bolts sometimes come loose, and the heat shield can either rattle or click when jolted.

 

Here's a video. Sorry it sucks, but you can hear the noise starting with the second rev. It sounds like dropping pins in a metal can. Any ideas? It isn't the heat shield.

https://www.youtube.com/watch?v=yG2c...ature=youtu.be