Original BMW Radiator Vent Line to Expansion Tank for BMW 330e (2016–2018)

On the F30 facelift BMW 330e, this Original BMW venting line connects the top of the radiator to the coolant expansion tank. A vent line of this kind lets trapped air and coolant vapor travel from the high point of the radiator into the expansion tank, so the cooling system can purge air and stay full of liquid coolant. BMW's name for the part is the venting line, radiator top, with the expansion tank noted as its connection. It appears as position 5 in BMW's cooling hose diagram for the 330e, which helps when matching it against the hoses already on the car. The part is sold as a single piece and serves the B48X engine.

Original BMW Parts carry a 24-month parts warranty.

The number has changed during production. BMW introduced 17-12-8-740-116 in June 2017 to replace the earlier 17-12-8-616-142, and marks the change as exchangeable retrospectively, meaning the newer line can be installed on cars that left the factory with the old number. Owners of an earlier 330e searching for the superseded number will land on this part. Because the 330e cooling layout is shown as its own diagram, this line belongs to that model specifically rather than to the conventional 3 Series sedans.

Technical Details

• Manufacturer: BMW
• Part number: 17-12-8-740-116
• BMW part name: venting line, radiator top, to expansion tank
• Diagram position: 5 in the 330e cooling hose diagram
• Replaces: 17-12-8-616-142, exchangeable retrospectively
• Production start: June 2017
• Sold as: one piece
• Warranty: 24 months

Common Questions

Will this fit a 330e built before June 2017?
Yes. BMW lists it as a retrospective replacement for 17-12-8-616-142, the number used on earlier cars.

Where does this line sit?
It runs from the top of the radiator to the expansion tank and is position 5 in BMW's 330e cooling hose diagram.

Fitment & Compatibility

Use the fitment table below to confirm year, make, model, submodel, and any notes tied to your exact vehicle. Pay close attention to engine, chassis, position, and option-specific details before ordering. PMB Performance has spent over 20 years matching parts to vehicles and can verify this against your VIN.