Mine does kinda the same thing. If I run 80+ mph empty, I use a gallon every 120miles or so. Yet if I run 90mph with a load on it, nada, nothing. driving around town, none either.
Only empty and over 80mph. Im going to put another breather assy in the fill tube and cross my fingers.
Im pretty sure mine is due to worn rings. been at 2000* EGT a few hundred to many times, plus it has 200K miles on it. But I dont want to do a compression check, just dont wanna know!!!
Ignorance is bliss.....:bang
If I were you, I'd check 2 things:
First check the breather for obstructions.
Second, and the most common problem: Check all your vaccuum lines. Mine had a vaccuum leak once and used a ton more oil. The vaccuum pump discharges into the crank case, pressurizing it if there is a leak. It will cause a poor ring seal, as well as more crankcase pressure.
It is the most likely culprit....and mine still operated the HVAC stuff and 4wd fine with the leak.
--Jeff
