I agree completely. But prior to knowing he had 67K on his car, it said in the thread that there was no leaks at all...It is possible to burn that kind of oil, maybe if it wasn't well cared for and had over 200K on it. :P Not the problem though...

 

Check around your intake plenum. Most common issue with GM V6 engines is intake gaskets. If you have a plastic engine cover, just twist off the oil filler neck and pull off the cover

Get a flashlight and look all around the plenum for oil. It could very well be collecting up there.

 

My car has a slight valve cover leak and I never see any oil on the ground but on my last oil change I noticed that one of the covers under the motor was full of oil.