Now if you have another buyer come look at it you can honestly tell them that the honda mecanic told you that "nothing was wrong with the engine", last time I had a honda mecanic take my car for a test drive to figure out why the idle bounced, he told me that my tranny was on it's way out, and a few other things that I should check, all without charge, of course that is the dealer ship that I buy parts from as well.
isolated tapping is usually a vibrating/harmonic issue. any crank bearing problems are noticiable throughout the rev range....95% of the time. Either a loose part somewhere or a complex bearing (ball, roller, tapered roller) which can have all sorts of failure-sounds.
1991 Toyota Pickup 22R-E 2.4 I4/5 speed
1990 Toyota Cressida 7M-GE 3.0 I6/5-speed manual
mechanic, carpenter, stagehand, rigger, and know-it-all smartass
"You don't get to judge me for how I fix what you break"