The dealer tried to blame me at first, said it was neglect, over heated, etc. The admitted that the head was not warped, block was not cracked, gaskets were good. Thus no explanation, so they fixed it, or so they said, about 30,000 miles later the problem reappeared again, took it back to the dealer, they did all the non-teardown checks, said they had no idea why it was happening, said it would cost $1500 to do it all over again, I said "go to hell" and took the truck to a small shop, they flushed the cooling system and it happens every so often, we flush the system and keep going until a real fix comes along.