Okay, I've been posting about this a lot. My dodge 5.9 magnum is still burning the same amount of oil as before. I've replaced the plenum, pcv valve, and the valve seals and still no progress. I've checked the compression and they all look very good. I use 10w-30 conventional oil and haven't added any additive to the oil. Starting to get on my nerves being that I have Gibson stainless headers, hughes intake, Cold air intake, MSD wires and dist, and big gulp throttle body with spacer sitting in the garage. I'm burning a quart a week and only when I'm hard on the pedal. Above 3k rpms and I can't see the road behind me. No loss of power. Let me know what you guys are thinking. 195k on the engine

 

also forgot to mention, 195k miles on the engine.

 

I had this problem with mine and did all the same things you did. Except I would empty the oil pan in roughly 5 days....it was pretty bad. It turned out to be bad rings. I found a motor with 80,000 miles on it, swapped my good parts and don't use any oil. Hope you figure it out.

 

What did your compression numbers look like? Did you do a wet/dry comparison test? Cylinder leakdown?

You have eliminated pretty much everything else, all that is really left is rings. With 195K miles on it, that really should come as much of a surprise.

I go thru a quart about every 100-150 miles. Still. Plenum has been fixed, PCV from dealer, etc. It's just time for a rebuild.