2005 3.8L looses 1 quart of oil every 2000 miles. There are not leaks at all around the motor. A guy told me that oil collects on the back side valve cover preventing the oil from draining back to the oil pan. Anyone heard of this?
If that was the case then the all the oil would end up in there and the pan would be empty.
a quart to quart and a half between oil changes is no concern.