engine knock @2000rpm

[truckertony]

well im not sure what this one is if i hold down the gas peddle @2000 rpm's while in park i get clunking noise from engine also if i let off the gas peddle and immedietly press down again some times it will clunk when its cooling down she clunks dealer put new cats on but no difference oh yey its a 2003 f-150 sc 4.2 liter i have made post on this same issue but no response so i figured i would word it a little different just maybe someone has had this problem.

[BlueOvalFitter]

The clunking noise you are hearing when your truck is cooling down are the catalytic converters.They get so hot when running that when you shut off the engine the rapid cool down makes the steel "creak". Mine does it all the time.

[mikelehmann]

sound like you could have lose flywheel or converter bolts. pully's will also makes this noise if lose. take a good look all around