Heard piston slap for the first time today...

That's right, I finally found out what piston slap is and just how bad it sounds for the first time today. Too bad it was on a late model OBS F-150! hehehe. I was at the county dump, about to get back in my truck, and I knew that a F150 was next to me. He started it up, and it scared the crap out of me! (you get a lot of echo inside the dump facility).