Original BMW Coolant Expansion Tank for BMW 5 Series, 6 Series Gran Turismo, 7 Series, and 8 Series (2016–2024)

The Original BMW coolant expansion tank, part 17-13-9-485-733, holds the extra coolant pushed out of the engine as it heats and feeds it back when the system needs it, on 2016–2024 BMW 5 Series, 6 Series Gran Turismo, 7 Series, and 8 Series models. BMW names it simply the expansion tank and started production of this version in April 2018. It is made in Switzerland and sold as a single piece. The coolant level is checked against this tank, so a body that has fogged from heat, age, and chemical exposure makes the level hard to read. Reservoirs of this type most often crack at a seam or molded junction after thousands of heat cycles, and a leaking tank can lower system pressure and the coolant's boiling point, which can lead to overheating.

Original BMW Parts carry a 24-month parts warranty.

This number supersedes the earlier tank, 17-13-8-610-655, and BMW rates the change as exchangeable retrospectively. That means the newer tank also goes on cars built before April 2018 that left the factory with the older part, which is why one tank covers 2016 and 2017 models even though its own production date is later. Across the G-chassis cars below, BMW uses the same tank with the four-cylinder B46 and B48, the six-cylinder B58 and B58C, and the plug-in hybrid B48X and B58X engines, so engine choice does not change the part on these models.

Technical Details

• Manufacturer: BMW (Original BMW Parts)
• Part number: 17-13-9-485-733
• BMW part name: expansion tank
• Supersedes 17-13-8-610-655, exchangeable retrospectively
• Production start: April 2018
• Country of manufacture: Switzerland
• Sold as one piece
• Warranty: 24 months

Common Questions

Will this tank replace 17-13-8-610-655 on my car?
Yes. BMW supersedes the older number with this one and rates the swap as exchangeable retrospectively, so it fits cars that came with the earlier tank.

How can I tell the expansion tank is the problem?
Look for a slow coolant leak that traces back to the tank, cracking at a seam, or plastic so fogged that the level cannot be read. Once a leak is traced to the tank, it should be replaced promptly.

Does the hybrid 530e or 745e xDrive use a different tank?
No. BMW uses this same tank on the B48X and B58X plug-in hybrids in the models covered here.

Fitment & Compatibility

Use the table below to verify the year and submodel for your build. With over 20 years of parts and fitment experience, PMB Performance can match this to your VIN.