BMW Cooling System Parts & Accessories for BMW G01 X3 xDrive30i B46 2.0L

Clear BMW chassis

Please ensure your correct model is selected

The cooling system is arguably the weakest point in numerous BMWs. If you drive an aging BMW or plan on taking your car to the track like we do, we recommend beefing up your cooling system before going to the track. Generally, the main components in your cooling system that are prone to failure include the following: expansion tank, factory hoses, water pump, thermostat, fan (especially if your vehicle comes factory with a clutch fan), and radiator. Factory BMW expansion tanks are plastic and prone to either breaking off at connection points or combusting. As factory rubber hoses age they either crack or break over time - we offer silicone cooling hose upgrades for most applications to avoid future failures. If you have an older vehicle, your water pump likely comes from the factory with a plastic impeller - we offer upgraded water pumps with metal impellers that are far more reliable. Newer model BMWs utilize electric water pumps - BMW spent millions of dollars engineering these water pumps, but they fail so often that we recommend replacing at 60,000 mile service intervals to avoid being stranded on the side of the road. In terms of thermostats, we offer various upgraded thermostats for racing applications. If your BMW utilizes a clutch fan from the factory, we have several options available in terms of universal electric fans - we recommend replacing these to avoid sending brittle plastic fan blades through your hood. For radiators, we recommend swapping out your radiator for one that does not use plastic connection points like your factory radiator.

Sub-Categories

Sort By:

Water Pump & Thermostat Kit - Gen 1 B46 2.0L
For model years 2018-2019
10X Entries Into Our F80 M3 Sweepstakes
Packaged by Turner - Corporate Logo
T#:35863149
Part#: 11518638026TKT
Ships in 1-2 days
Sale - Save 5% $ 740.99

This product was last offered at the strikethrough price on
09-09-2026

$ 705.38 USD
Free Shipping on orders $49 and up
Sale - Save 5%
$ 740.99

This product was last offered at the strikethrough price on
09-09-2026

$ 705.38 USD
Free Shipping on orders $49 and up
BMW's cooling system has long been a known weak spot, with the water pump and thermostat being two of the most common trouble areas. This remains true even in the latest B-Series engines found in 2016 and newer BMW models. This kit includes a brand-new OEM Pierburg water pump, a Bremmen thermostat (now referred to as a Heat Management Module), and one gallon of BMW's G48 coolant concentrate (enough to make two gallons of 50/50 coolant). Avoid spending thousands at the dealership or over $600 on Genuine BMW parts! These components can be replaced with high-quality OEM parts in just an afternoon using basic hand tools.
Show More Show Less
Rein Coolant Expansion Tank - With Cap
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:53891623
Part#: 17135A6A030C
Ships in 4 Business Days
New Item
$ 99.99 USD
$ 99.99 USD
Replace your old brittle expansion tank
Rein - Corporate Logo
T#:55965839
Part#: 17138610661
Ships in 4 Business Days
New Item
$ 56.99 USD
Free Shipping on orders $49 and up
Keep your ultimate driving machine cool under pressure with this replacement auxiliary expansion tank from Rein. On modern turbocharged BMWs, the secondary cooling system plays a critical role in managing intake charge air temperatures, making a solid reservoir vital for both spirited street driving and track day reliability.
Show More Show Less

Rein Thermostat Assembly - F Chassis, G-Chassis - B48
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:53891628
Part#: 11537644811
Ships in 4 Business Days
New Item
$ 322.99

This product was last offered at the strikethrough price on
06-10-2026

$ 288.99 USD
$ 288.99 USD
Whether you're managing a fleet of "spirited" daily drivers or prepping a chassis for the circuit, the Rein CTA0079 offers the peace of mind that comes with OE-quality engineering.

Rein - Corporate Logo
T#:55965843
Part#: 171386106612
Ships in 4 Business Days
New Item
$ 49.99 USD
$ 49.99 USD
Keep your ultimate driving machine cool under pressure with this replacement auxiliary expansion tank from Rein. On modern turbocharged BMWs, the secondary cooling system plays a critical role in managing intake charge air temperatures, making a solid reservoir vital for both spirited street driving and track day reliability.
Show More Show Less