Engine Coolant Reservoir Cap

The Precision Raceworks Engine Coolant Reservoir Cap is a functional and stunningly  stylish way to add a nice touch to any engine bay! This cap come in three color options so there is always a color that will work for you! Black with Billet, Black with Blue, and the Stealth series (all black). Many people don't realize it but the OEM caps have a pressure release valve built into them.  Often times aftermarket companies don't know this either or just don't care.  But our team cares about proper function just as much as we care about the appearance in every product we design. For pressure relief, our caps incorporate the OEM internals, so you get all the functionality of the original caps, ensuring a safe and reliable system in place. These caps offer superior style and performance-grade components that guarantee a reliable fit every time. Durable billet aluminum construction provides long-lasting protection and dependability that will upgrade your engine bay for years to come. Other companies make covers that install with adhesive over your factory caps and can come off over time. These caps offer superior style and performance-grade components that replace the factory cap not just cover it up. Durable billet aluminum construction provides long-lasting protection and dependability that will upgrade your engine bay for years to come! PLEASE NOTE: These do require assembly and swapping the pressure relief valves from your old caps to your new billet caps.    Fitment Note If your primary expansion tank cap looks like this: You will need to purchase a different coolant expansion tank cap to use as the donor cap.  BMW Part number 17117639021