My CEL was on and it happened to be that my intake was not tight therefore there was a leak. I tightened the clamps and no more CEL. (I have a CAI)
Ever since then I hear a noise that seems to be caused by RPMs, although I hear it at its loudest when sitting at a stop light on the brakes.
I don't think that is the cam synchro because it doesn't really sound like a chirp. I have a video on the sound.
Note: Its loudest in the begging (first 10 seconds). And the sound tends to be getting a little bit louder day by day.
I don't know If I should worry about it. Could it be the coldness and bad roads causing something to move around?
Anyway, heres the video:
1999 XLT 4x4 3.0 Flareside
Off Road package, Towing package, 4.10's, 123k miles