Ears in Richmond VA

My Jeep has just started making a new noise at idle. From searching earlier posts I think it may be Piston Slap. (rattling bolt in can, diesel engine, etc.) Noise goes away above 1k RPM's drives great, no other symptoms. Noise is louder if you crawl under Jeep. Seems to be loudest around the oil pan, but it's really impossible to tell. Is there anyone in Richmond who is familiar with the sound of piston slap, willing to take a listen? I am usually out driving around for work each day in different parts of the city and could drive it by and let someone take a quick listen. It's a 4.0 with AW-4