Knocking on 1995 sebring lxi coupe 2.5 v6

Ok so about a few months ago, I was driving down the freeway and my car went completly out of gear, no prior issues before this. the car over heated and I parked it and got it towed. the knock is coming from what seems to be the passanger side back lower area. and under near the oil pan.
once I got it home I noticed there was a steady load knock. the knock was not load while in park but once it goes into drive or rev it gets loader. when I give it gas the sound goes away, the idle is irratic up and down but I think thats because of the leak in the egr valve. could that cause a knock? So far I have already had 3 diffrent people come start replaceing what they thought it was and the noise is still there. replaced sparkplugs, wires , oil is clean altho a small amount of white resadue  in the oil pan but there is none in the rad. replaced all the bearings , pulled off all the tentioners and pulleys and when I started it up the sound was gone. but onces the belts were back on it was doing it agian. the sound goes away when I am driving and comes back when I let off the gas and starts to stall. agian I think the stall is egr but the knock is coming from the lower end.  this car does not have a knock sensor. comprestion on the car is correct, there does not seem to be any real problem.. but there is that knock and it was never there before. anyone have any ideas on what it could be?