I have a 2001 dodge dakota quad cab 2wd automatic and it has a knocking noise when first start the truck but it somewhat goes away after about 5 mins as its still there but quieter as you can't really hear it in the cab of the truck but if you lift the hood or listen for it under the truck it's this there. When driving if I put in neutral the noise its not as loud even if i rev it in neutral but soon as it goes back to drive or reverse the noise you can hear it more. I hear it more in the bell housing and you can hear it in the transmission pan when I put my ear up to it but I can't hear it in the oil pan when I put my ear up to it. I've unbolted the transmission and pulled it back to look at the flexplate and it was good no cracks and started the truck with the troque converter not bolted up and still heard the knocking cuz I was thinking it was either the trouqe converter or the flexplate cuz that the area that I can hear the noise the most. I did a comparison test and all the cylinders was about 150 psi so there pretty even. I got a digital multimeter and the coil packs and injectors all read the same in spec. Put a 2004 intake manifold a year ago and just put in new champion copper spark plugs in and the old ones where only a couple years old and still looked in good shape. I put new exhaust manifolds gaskets and new magnaflow y pipe and dual muffler and k&N air filter and tube kit and new rockers and lifters a new Coyle timing chain kit a year ago and its seems to still be tight there no play in it. I took the belt off the alternator and pulleys and the noise was still there. So I'm down to if its a rod knock or a crank bearing or may may a sticky valve or valve seat drop but all the cylindersare reading the same comparisonat 150 psi ? I have good oil pressure and the truck still has lots of power. I use synthetic 5 30 moblie 1 oil. I put some lucus synthetic oil additive and a zinc additive and didn't see anything difference in the sound. So I'm gonna buy a scope camera in the next few day and look in each cylinder and go from there