hey guys well heres the deal. at first it always did the timing chain rattle. i ran some oil and marvel mystery oil . then it went to not doing it on a cold start as long as it was warm out . and now it doesnt do at all until its warm. i used the mechanic stethascope i have and couldnt tell a darn thing. my buddy has a sunfire and with the stethascope they both sounded the same not bad just sounds like you can hear the chain going not slapping or anything like that. his car has the same noise but itsnt as pronounced as mine. i listened to the lifters lower end of the engine everything. the noise is loudest if you stick your head on the passenger side fender well. i did take off the seprentine belt and listen to it. sounded the same. when i bought the car there was half a quart of sae 30 non detergent motor oil in the trunk i dont know if it was used in the car but i wonder. what you guys think? thanks i appreciate any help.