My 94 has had a persistent knock coming from the motor. It's more audible when warm, and between idle and 3000rpm. If I rev it to just under 3000 in drive and let off, it'll clatter, almost like a rocker arm. Did the 4.0 OHV have issues with the rockers in 94? I also wonder about the wrist pins in these motors. Has anyone had the wristpins loosen up? I'm not finding any metal in the oil, and I just changed it a few weeks ago. If it was a spun bearing, it would have worn thru the crank by now. Ive been driving it this way for almost 1000 miles, and it's getting a little louder now. Any other ideas? The engine has almost no power, but I think that's another issue (lean in both banks according to the codes, and very bad spark knock). This is my only vehicle, so I have to keep driving it for now.