Will the oil drain back through the oil pump?  Is this something I

should be concerned about?

Bob W.

 

Bob;

 

I would say “No”.  For the oil to drain out air would have to go in.  Where would that come from?  I don’t know your plumbing, but it would have to come all the way back from the ports in the engine, presumably through the oil filter.  Not likely. 

 

Al G