the engine pictures look alotlike my moms 2012 mazda 6. (design, not condition) christmas eve she was on her way to work early in the morning and drove through high water, inhaled enough water into #1 cyl to hydrolock it, bent and broke rod, piston cracked. when the rod broke, it flipped around and punched the oil pump off the bottom of the block and left some holes in the pan as well. amazingly the block was undamaged. we put in a new piston, rod and oil pump, new oil pump drive chain and a oil pan. motor had 17,000 miles on it, was on its 2nd oil change. (1st was factory fill, had mobil 1 in it and was due for a change when mom gave it a bath) motor was incredibly clean inside, as you would expect a year old engine to be with under 20K miles. its been back on the road again for almost 2 months now, noticed the skyativ logo on the trunk and want to put a sticker under it, so it will read "skyactive.....water, not so much" she still has issues with the trunck realease and fuel door cables not working until the car has ran for quite awhile, had a dehumidifier in the front seat and it worked well, could never tell it had 4" of water in the interior. bet mom never goes through standing water again. that gm engine looks like something i would expect of a 50,000 mile engine with a open thermostat and [censored] oil that was only changed every other year.