I noticed yesterday that my coolant tank is a white in a couple areas about the size of a golf ball. Just out of stupidity, I picked at it with my fingernail and scrapped some of the plastic away. I literally took a layer off with my fingernail. I'm obviously gonna replace it, but I'm curious if anyone else has had this problem? I'll take a picture of it tomorrow and post it. Any ideas why the tank would be deteriorating? It's on the top portion so it's not submerged in the coolant or anything.