BMW e60 e61 e63 Coolant Expansion Tank + level Sensor water overflow reservoir Coolant Expansion Tank with Level Sensor NOTE: does not come with cap, use yours or email for a new one. BMW part# 17 13 7 542 986, check fit below. Genuine BMW part, recently made: not been lying around. Please see FITMENT CHART below, under PRODUCT DESCRIPTION. Email us your VIN for any questions.