I just bought a '98 200sx. It makes a noise that sounds like rattling tin (I thought it was just a loose heat shield) between 2500-3000 RPMs. Upon further inspection I determined that the noise is coming from the valve train. So my question is are there any things I can do like tightening lifters or something to quiet them down? It is pretty loud. Also the front crankshaft seal is leaking quite a bit. Would running the engine out of oil cause noisey valves? I am starting to wonder if the previous owner ran it out of oil.