Recently changed the oil and filter, along with the front brake pads on my '12 3.0 gas engine.

A few days later, I was sitting at a stoplight and heard a faint noise and I thought it was the car next to me. Didn't pay much attention until the next light, when I heard it without the other car there.

It's a very very faint noise, imagine someone taking the handle end of a screwdriver and tapping under the front left of the car just hard enough to barely create a sound. If the radio was on, you wouldn't hear it.

The sound happens about every 3-4 seconds. Racing the motor doesn't change the tempo. It's just a steady, every 3-4 seconds, very faint "knock". Kind of hollow sound, that's why I said it sounds like the handle end of a screwdriver hitting something. You can only hear it when sitting still. It might be happening when moving, but you can't hear it.

Only thing done is the brake pads and the oil and filter. Everything seemed normal during those changes, nothing jumped out at me.