Maybe you haven't read the ad:
Quote
Buyer agrees to as is/where is, no guarantees or warantees and understands that the vehicle is being sold due to engine knock. I am not a mechanic, therefore I can only tell you what I was told. Possible lifter problem, however could drive for years.

It is more an issue of him scaring off potential buyers with the way he wrote his ad that will keep the price down. He knows it is probably lifter noise, the guy just doesn't want to deal with it. So I don't see an ethics problem here.

Steve Carlson - 95 Trooper LS expo rig
Serenity now!