Valve Tapping

[usfstud27]

I have a 1994 GS300 and there is a tapping sound coming from the top of the engine near the cams. I have narrowed it down to the valves and was wondering if anyone can tell me what the exact problem might be. The car runs fine except for making a loud tapping sound. I figure it must be a bad cam follower but would like to hear the opinion of a professional or DIY veteran. Thanks for the feedback...