cracked. Any ideas why? Is this a problem with the radiator or the mechanic. I was on vacation out of state when this happened and original mechanic wont be able to look at it. I did take a picture of the crack. Took it to a BMW dealer. Any advice would be appreciated. Is there a manufacturer warranty on radiators? Labor? Do you think the mechanic or radiator manufacturer would pay my rental car bill?

Its common for a radiator to get the point of needing replacement but its to late the damage is already done and the engine ran hot or even overheated. Now you had what I called a super heated moment. Where the head is likely cracked and some very hot air slipped into the radiator and expanded and cracked the radiator.

I tell my customers who need colling system work that the head will likely crack soon. And so far its not likely it happens every time. You story is one told over and over again by owners. Just replaced my radiator/thermostat/whatever in the cooling system and a few weeks later the head is cracked.

Of you just got a bum radiator..