Original BMW Coolant Expansion Tank Hose for BMW 230i, M240i, 330i, 340i, 430i, and 440i (2016–2021)

Made in Germany, the Original BMW expansion tank line 17-12-8-616-531 carries coolant between the engine cooling system and the coolant expansion tank on 2016–2021 BMW 230i, M240i, 330i, 340i, 430i, and 440i models with B46, B48, and B58 engines. As the engine heats up and the coolant expands, this hose moves the excess into the reservoir, and as the engine cools, it lets coolant flow back so the system holds the correct level. A leak here lets coolant escape, which can lead to overheating and can trigger the check engine light through the coolant temperature and level monitoring. The hose weighs 184 g (0.4 lb), and BMW began producing this number in July 2015.

Original BMW Parts carry a 24-month parts warranty.

BMW uses this one line across the four-cylinder B46 and B48 and the six-cylinder B58 engines in the F2x, F3x, and F3x/F4x chassis it covers, so a 330i and a 340i of the same era share the part. Confirm your car's engine and build date against the fitment table before ordering.

Technical Details

• Manufacturer: BMW
• Part number: 17-12-8-616-531
• BMW name: line, expansion tank
• Weight: 184 g (0.4 lb)
• Production start: July 2015
• Engines: B46, B48, and B58
• Country of manufacture: Germany
• Sold individually
• Warranty: 24 months

Common Questions

Does the 340i use the same hose as the 330i?
Yes. BMW fits this line to both the B46/B48 four-cylinder and the B58 six-cylinder engines in these chassis.

What happens if this hose leaks?
Coolant loss can cause overheating and can set the check engine light through the coolant temperature and level monitoring.

Fitment & Compatibility

Check the table below for the exact year, model, submodel, and any listed notes. With over 20 years of parts and fitment experience, PMB Performance can match this to your VIN.