need help diagnosing for a friend

i work on this friends jeep alot, fortunately i dont have very much experiance with engine diagnosis. He is burning about a quart of oil a week in his straight 6, this process hastens in 4wd, i have no idea what it could be, valve cover gasket was replaced 10k miles ago

 

Valve cover torqued back on properly?
Blow-by?

Are you positive that it's burning instead of leaking?

 

are you burning it.....
bad rings mabye

 

the 4.2 carbed. I think i was reading something about it in the jeep forums yesterday

 

If he's burning oil, then his rings are worn or bad valve seals. Could be a bore and piston job or a valve job.

 

any idea why oil usage would increase in 4wd?

 

Would think so.

Leaking a Qt a week there would hopefully be signs of leakage on the ground, at least coating the undercarriage. Might as well see what the coolant looks like also.

Engine is working harder in 4x4. Same reason gas mileage goes down in 4x4.

 

ill pop open his hood at school tomorrow and check for leaks, thanks for the input ill keep yall posted