After an extended trip in the last two days, I happened to check the tightness of the screw on oil filter. To my surprise it was about 1/2 turn loose and oil was leaking out.
I noticed this looseness right after I bought it and tightened it then. When the dealer gave me the free oil change, the filter was on tight.
I have never seen this happen on any car I have owned. What could cause the filter to become loose after it was properly installed at the oil change?
The car has 25K miles. The car is a 2013 LaCrosse V6.