I know what you mean, mine gets a ticking sometimes that sounds like some serious metal wear going on. And when I 1st crank it and after reving, as the RPMS slow down, the piston knock sounds like a diesel motor. Its been doing all of that for over 150,000 miles and its still going. Slick 50 quiets everything down really well until you drain it out with an oil change. Here's something funny, my old neighbor was a 18 truck wheeler driver, had his own rig. He always thought my truck was diesel, because it sounded like his big rig. He borrowed my truck for some reason and tried to gas it up, but didn't because the diesel nozzle wouldn't fit or maybe he saw the unleaded gas sticker on the gas door, I can't remember which. It confused him so he held off.