so as the tittle says. recently my car has a slight tap on cold starts. i can tell is a sticking valve it will go away, it starts rough idle low idle. once the slapping sound goes away from the valve hitting the rocker arm it idles smooth clean at 1.5k until it warms up after the slapping sound goes away it will never come back until the morning after. im going to have the head rebuild with bisi parts, just want to know what can cause a valve to get stuck like that? i doubt it's a bent valve as the car does not missfire, backfire, kill fuel etc, great gas millage. one time i got 350 miles to a full tank i think i could of got 400 miles but i ran the a/c a couple of times