Tester
What’s wrong?
Why not to use 0w500 
Whoa! That’s quite a sight.
This is obviously a prank. Motor oil on its own is not going to polymerize into a rubbery material. Even if coolant leaked into the oil, I very seriously doubt it would turn into this stuff. I call BS.
I think someone dumped some stuff that they shouldn’t have down the oil filler. Maybe some Jell-O 
I just knew the Quaker State / Knox Gelatin merger was gonna cause problems.
Forget gelatin.
It has to cool to set after boiling.
But add corn starch to a liquid that’s already hot, guess what happens?
Tester