Ok, this is my first post with this group. My girlfriend drives the xterra, and I drvie a dsl truck. We are having a problem when the truck sits over night and then in the morning when she starts it makes a knocking sound or a loose metal sound until motor oil gets up into the top of the motor and then goes right away. Any ideas why this might be happening? When she stops and goes shopping and comes back in an hour or so it doesn't do it or if it does it is so quiet or faint we can't hear it. Why is it that it only does this at start up, after the engine has sat for a while. What can we do to fix it? It is a 2003 Nissan Xterra V6 3.3 non supercharged with 100k miles on it. Just clicked over. Or should we get rid of it and get a new one? We like this body style better then the new ones.

John