Lately my truck has been smoking a lot. I'm am really struggling to figure out if its just running rich or if its burning oil.

The motor has about 10k on a complete rebuild. It was my first rebuild ever and I didn't break it in as well as I should have. Its also had an oil leak for a while and I'm ashamed to say I have run it pretty darn low on oil on a few occasions. Never lost oil pressure though!

The smoke is black if I floor the pedal - definently rich then. But if I rev it gently its just grey, with maybe a hint of blue, but its not clear cut blue oil smoke.

Compression when cold:
1: 160psi
2: 165psi
3: 160psi
4: 150psi (this goes to 165psi if I squirt some oil in)

So clearly the #4 rings are worn a little, but is that enough to give a steady flow of smoke?


Thanks,

Scerb