Original BMW Return Line Coolant Hose for B58 G01 X3 M40i and G02 X4 M40i (2018–2019)

Built for the B58-powered G01 BMW X3 M40i (2018–2019) and G02 X4 M40i (2019), this Original BMW coolant return hose is part of the heater circuit that carries engine coolant to and from the heater core. BMW names it "coolant hose, return," and it appears as item 2 on the heater hose diagram for these models. BMW shows production of this number beginning in August 2017. It is sold as a single hose.

Original BMW Parts carry a 24-month parts warranty.

Heater hoses route hot coolant from the engine to the heater core behind the dashboard. The blower motor then pushes cabin air through the core to warm it. Because these hoses are also part of the engine cooling system, a leak here lowers the coolant level and can lead to overheating, along with weak or missing cabin heat. The return hose brings coolant back from the heater core. Make sure you have the return line and not the feed line before you order.

Technical Details

• Manufacturer: BMW (Original BMW part)
• Part number: 64-21-9-354-464
• BMW part name: Coolant hose, return
• Diagram position: item 2, heater hoses
• Engine: B58
• Production start: August 2017
• Sold as: one hose
• Warranty: 24 months

Common Questions

What are the signs of a failing heater hose?
Look for cracks, a soft or deteriorated hose, leaks at the connections near the firewall, a falling coolant level, a coolant smell under the hood or inside the cabin, or a heater that gives no warmth.

Does this hose fit the X3 xDrive30i?
No. BMW lists it only for the M40i in the X3 and X4.

Fitting the correct return line restores both cabin heat and cooling system integrity on your M40i.

Fitment & Compatibility

Use the table below to verify the year and submodel for your build. PMB Performance has spent over 20 years matching parts to vehicles and can verify this against your VIN.