89 bronco II engine tapping

I have an 89 bronco II and it has a BAD valve tap. A buddy of mine mentioned that all I would have to do is adjust the valve that is tapping. I have lost contact with him and he never told me how to adjust the valve. He mentioned something about intake and exhaust. Please help, I know a little about cars, but nothing like this before. It is extremely loud!!!!!

I had a tap (until today) what oil are you using? my manual suggests 5W-30 for anything under 100 degrees ambient (outside) temp. But what I did to take car of the tapping. Was use Seafoam. Go to NAPA they have it. I used 1/2 a can (can is a pint) in my oil. 1/4 can in my gas tank (had a quarter tank) and 1/4 can straight into my motor.

take the brake vacuum hose that runs straight from the intake manifold to the brake booster cylinder take the brake cylinder part off. hook a funnel up. then when your idling pour 1/4-1/3 of the can slowly in while the truck is idling. if it won't idle with the hose off then have a buddy give it some gas.. now it WILL smoke (mine did ALOT) this is just all the gunk cleaning out. after you put it in hook the hose back up. let the truck sit for about 5 minutes and drive it around the block.. it will smoke here too. mine smoked so much looking through my rear view mirror i couldn't see anything.. And now my truck seems to idle better and just overall run better. Give it a shot.