Ever since I bought my 84 ram 50 turbo diesel it smokes horrendously and idles rough. The power is inconsistent as well. I checked the compression at the glow plugs and it was good. However I noticed oil coming out in the fuel. I checked the turbo and it is fine. The truck is not burning antifreeze and the oil level doesn't seem to go down. What could cause this? Could it be valve seals?