i have a 2000 honda civic with 120,000 miles on it. recently, on cold starts (when i haven’t turned the engine for a day) i’ve noticed a rapid vibrating or rattling noise about 30 seconds or so after i’ve turned the ignition. this noise lasts for maybe 15 to 20 seconds then it goes away, presumably as the engine has warmed a little. i do drive a lot, and during the day even after the car has not been running for a few hours this noise doesn’t occur. only happens on the cold starts. i could sure use the car talk community’s help on this. i hope it’s nothing major.
i’ve attached a video with the sound. about 30 seconds into the video you will hear the noise kick in. (if the video doesn’t show below here is the youtube link: http://youtu.be/LVyj8M0nkIA