not sure if you can see it but yea, if you look closely, you will see one of the valve stem plates are crack and metal pcs are already scrapping the cylinder walls. there were oil all over piston # 4. it made sense cause i saw chunks of pcs on the tip of the spark plugs when i remove them.

i think the oil was so black that you can't really see it but it's definitely cracked. i even through it in to get it hot tank and damn it looks jacked up.