Coolant expansion tank replacement on a 2001 BMW 330i is our featured repair today.
This BMW was towed in due to a sudden loss of coolant. The culprit was a cracked expansion tank.
The expansion tank is made of plastic and like so many other plastic parts on cars eventually gets brittle and breaks.
Unfortunately there is usually no warning when these parts fail. BMW is not the only vehicle to experience these concerns. Volkswagen, Mercedes, Jaguar and Audi, just to mention a few manufacturers, also suffer from sudden failure of plastic parts.
The best prevention is to simply replace the high failure items every 10 years or so.