2004 Nissan Altima w/manual transmission

Using 1-2 quarts weekly. Dealer diagnostic show no pproblem.No visible oil leaks. Approx. 80,000 miles. Travel 100-200 miles weekly. Anyone having this problem?

Not familiar with your engine, but I would dismantle the oil mist separator where the PVC system gets its air. That is often in the valve cover on Nissans. If its drains get clogged with sludge, you start pulling oil through the PVC and burning it. Since the oil burn rate is slow and happens mostly at highway conditions, you don’t notice any smoke.

If the mist separator is permanently attached to the inside of the valve cover, you may need to drill out the oil drain holes bigger, or if it is really crusty, you may need to get it soaked and steam cleaned to remove hardened sludge.

“Using 1-2 quarts weekly.” "Travel 100-200 miles weekly."
Wow, That’s A Quart Every 100 Miles ! That’s Major Oil Consumption.

Did the problem come on suddenly or slowly and then accelerated ?

What is the lowest oil level this engine recorded, measured by how much you had to put in to fill it . . . 2 quarts, 3 quarts, etcetera ?

Is the “Check Engine” light on yet ?
The dealer didn’t find a problem ? Are you kidding me ?

CSA

No engine light has come on and the diagnostic test the dealer did didn’t show any problems. Not sure if it started suddenly but sometimes the heater won’t work. May be a connection there?

" What is the lowest oil level this engine recorded, measured by how much you had to put in to fill it . . . 2 quarts, 3 quarts, etcetera ?"

Does the heater blow cool/cold air or stops blowing (no fan) ?
CSA