Even though the following may not pertain to this thread's motor issues:

I cannot stress enough the apparant tie-in between high oil usage and failure to change the PCV valve regularly. I found this out myself from this board. My VX always used a normal amount of oil between oil changes since it was new; and then, used almost a quart during a particular oil change period.

I found some posts on the subject and changed my PCV (less than 5 minutes in the AutoZone parking lot.) and the oil usage returned to normal immediately. My last 3,000 mile oil change interval barely used any oil at all...just under full on the dipstick.