Ok guys, this is a bit long,,, but I need some expert opinions.

I was running down the interstate, at 70mph, when I heard what sounded like a couple pieces of gravel hitting under the body of the truck. I also heard an immediate sound change in the road noise. I kicked the trk in neutral, engine dropped to idle, sound continued until I was under 55 mph. Engine runs fine, plenty of power. First thought, drive line... everything tight and ok there. Continued on,, heard the gravel sounds again, (very loud) during deceleration. Checked everything I know to ck.. Drove on.... This time I heard it during acceleration, and it sounded like it was maybe in the exhaust system,, kinda like an engine ping or a rapid exhaust backfire. Still not sure what or where... Engine runs fine....

'00 7.3 PSD, 233,000 miles

Any suggestions,,, Thanks guys

 

Still pondering this one... BUMP

 

Well don't know if you have auto or stick, catalyst or not , but check and make sure all bolts are tight on torque converter flex plate or if it's a stick pressure plate bolts. Sounds like something came lose. If you have a cat it could be rattiling, check about every bolt you can and see if there is any missing.