Originally Posted by bigpoplin
Well it has been in the mid 20's to low 40's in North Carolina. The guy I bought it from had a tech at meinake look at it and he said probably an exhaust leak but I'm doubting that
Exhaust leak tends to sound more like a spit spit spit on the 4.0... where if you have any of the jeep manifolds, in my opinion they suck.
I'd suggest the widest viscosity range synth or synth blend you can get for the 4.0. 20-50, 10w-50, etc. And Seafoam it, plus add a bit to each oil change.
If the valve cover and/or rear seal aren't leaking, they should never burn oil.
Hesco used to make a cool aluminum valve cover.
Caution, the oil pressure sender on the 4.0 can be quite unreliable, and it only takes about 5 minutes to change.