Everytime i start my car in the cold weather, or sometimes even in general weather, i have a knocking or tapping noise coming from where it sounds like inside of my engine. I have been talking to people, and showing them videos of the sound so they can hear it, and i asked if it was a rod knock or piston slap, but they said they were 100% positive it wasnt. So, i came up that it could possibly be a bad coil plug not firing right. when its cold, i play with the throttle body, and rev it to ~1250RPM and let it go, and then the sound comes back. As i was talking with people, they said it could be the timing chain adjuster (plastic part in the engine by the timing chain) and the chain could be slapping against it due to slack in the chain. But, thats not the end of it. During the summer when i was on the highway getting on the on ramps, flooring it, i was in 3rd gear at about 3400RPM...and then the noise is there going with the RPMS as they go up. So, if anyone has any ideas of what this could be, please let me know, i can send you a video via email of 2 short clips of the sound that are OK quality and you can hear the noise...just give me your email, or email me at Mustang98GEETEE@aol.com and ask for the videos to see if you know what it is. Thanks!