[fredjacksonsan]

First, you should read the documentation for the Tigershark warranty.

After that, if it says that this is covered… Then it's time to bump this up to Stellantis corporate offices and go over the dealer's head.

A blown head gasket does not require overheating to occur; it can fail without any overheating at all.

It sounds to me like your dealer simply doesn't want to do the warranty work… And is looking for an easy way out and collect your money. Warranty is a warranty, and I think they may have to prove neglect. If you never saw any indications of overheating, then guess what… it didn't overheat and the head gasket simply failed.

I would ask the service manager what signs of overheating he noticed… Call him out on it.