smoking

my truck doesn't smoke when you start it up but after it runs for about ten minutes it starts smoking. it was smoking really bad but as a last resort i put a bottle of no smoke in it and it still smoked so i got pissed and turned it off i let it set for about a month and today i started it back up and it did it again only the smoke is not so bad. why would it not smoke upon start up but smoke later? any ideas.

Just a guess but if it doesnt smoke on start up but does when it gets warm,something is getting hot ,expanding and letting a small amount of oil leak thru and cause the smoke.My guess is a worn or cracked oil ring or a worn valve seal but that is just a guess.BJ

my rockers are tapping like crazy and i was thinking maybe a head problem but i think you have to take most of the engine apart to get the head off.