Ok, I've been trying to diagnose this noise that JUST started the other day.
I took off nice and hard from a 1st gear roll and all of the sudden, heard this nasty, metallic rattling from the engine bay. I had a Steeda intake and Bama tune on the car. I decided to return the car back to stock to see if the noise would go away. Well, with the factory airbox in place, I could barely hear the noise, and it seemed to be coming from the shift boot area (or underneath the car).
I then thought it was related to the shifter or tranny. I could only here the noise when accelerating.
I took it for about a 25 minute drive tonight, still trying to figure it out. Car runs great, just hearing the noise. I decide to stop in a parking lot. I jump out with the engine running and everything sounds fine. I then pop the hood, and I could hear a lot of ticking/light knocking/rattling come from the engine. With the hood down, you can't hear a thing (so it's not very loud).
This was with the engine nice and warm. When the engine is cooler, there is no ticking/rattling at all, even with the hood up (not sure if the rattling/ticking sounds are normal as I've never listened to the engine with the hood up after it has be running hard for awhile).
I seen another vid on youtube, where this guys Mustang was making the EXACT same noise from the shifter area. In his description, he mentioned it was the cam phasers. So, I start doing some research and it seems like that may be the issue with my car. I've read that problem cam phasers can be heard when your car is hot/has been running a while. When the engine is cooler, the noise will go away, etc...
UPDATE: I think for now, since it is just a faint sound, I'll just monitor it. I'm sure if I took it into the dealer as it stands, I'll get the standard, "Oh, that's just normal."
There is no direct valve-train noise, no loss of power that I can tell, no loss in fuel economy, so it doesn't appear there is a concerning issue with the cam phaser/VCT system at this point (if the sound in fact is related to the cam phaser in the first place). If I start to notice any of the before mentioned, I'll take it in for sure.