Expansion Tank - F80 M3, F82/F83 M4, F87 M2 Comp (S55) - 17132284600

The engine cooling system of the S55 powered M models has an overflow reservoir, more commonly known as a coolant expansion tank. This tank is made of a composite plastic, and like all plastic components it is susceptible to damage, cracks, and leaks. Often a leak can occur seemingly randomly, due to the constant heat cycling, hot climates, over-pressurization, mileage, aggressive track driving, and age/time. 

This expansion tank is specific to the S55 models, which includes the 2015-2019 F80 M3 Sedan, 2015-2020 F82 M4 Coupe, 2015-2020 F83 M4 Convertible, and the 2019-2021 F87 M2 Competition Package. It's also the same tank used on both the M4 GTS and Motorsport M4 GT4. These models were offered in 2015, 2016, 2017, 2018, 2019, 2020, and 2021. 

This tank includes a new expansion tank cap, as well. 

These generally have a long lifespan, but when a leak / crack forms, it's going to lead to a loss of coolant, overheating, and a general mess of coolant in the engine bay. Fortunately replacement of the M3 / M3 / M4 coolant tank is quite straight forward, and another new Genuine BMW tank will last many years to come. 

This is the original / authentic / Genuine BMW part, which is BMW part number 17132284600 (17 13 2 284 600).