D'OH! Didn't even think about the oil level- - - - -that's the logical place to start. If there's a floating pickup screen, there's a possibility of it getting stuck in the up position and sucking air, even if the oil level is only slightly low.

I'd drop the pan just on general principles- - - -the cost of a pan gasket and a little aggravation sure beats a trashed engine!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!