Knocking/Rattling Sound when stopped with brakes applied.

[darkslide18]

2014 Scion FRS Automatic with 32,000 miles bone stock except for an Injen CAI and a Flow Master Catback. Had both the CAI and Catback before this sound appeared.

Ok, so I have a knocking/rattling sound coming from my engine bay during very specific circumstances. When I come to stop with my brakes applied I get this loud rattle.

Mind you this only happens when at a complete stop with the brakes applied in Drive. If I shift into Park with the brakes applied the sound goes away. When I let go of the brakes and start to move forward the sound disappears.

It sounds like a loose heat shield but over the weekend I jacked up the car and could find nothing. Checked covers, heat shields, and even checked the manifold bolts on the engine and leading to the front pipe.

Im going to take it to the dealership in the next few days but wouldn't mind any suggestions here so maybe I might know what direction to point the mechanic in when I do take the car in.

[Ultramaroon]

You're likely on the right track with the heat shield theory. Unfortunately, the sound is only presenting itself with torque applied to the drive train.

I can only tell you what I wouldn't do. I wouldn't put it up on stands and run it with the hand brake engaged. I definitely wouldn't get underneath it to look around while it was running on the jack stands in drive with the hand brake engaged. That would be unsafe.

[DarkPira7e]

Definitely sounds like heat shield resonance. Good plan to take it to them and have them find it