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BMW Cooling System Parts & Accessories

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.

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Moroso Aluminum Coolant Expansion Tank - E9X Non-M
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Moroso - Corporate Logo
T#:29666105
Part#: 63851
In Stock at Vendor
$ 488.99 USD
Free Shipping on orders $49 and up

The coolant expansion tank provides hot coolant with a place to travel, preventing pressure buildup within your cooling system. On many BMWs, this component is constructed from plastic. While cheap to replace and manufacture, a failed cooling tank can cause costly engine damage.

With this issue in mind, Moroso designed a high-quality replacement. Featuring TIG welded, 100% aluminum construction, this tank is sure to outperform it's factory counterpart.

Features:

Key Benefits:

Direct bolt-in replacement for stock, 2 piece plastic tank Fabricated Aluminum for strength, factory tanks fail after repeated high heat situations & age Features billet aluminum mounting tab/bleeder assembly for strength and precision No cutting of factory hoses is required and accepts the factory clip-on hose Moroso part (63324) racing radiator cap included; operates in the same pressure range as the factory cap Moroso radiator cap mounts to a billet aluminum neck that will not strip out like plastic threaded necks This aluminum tank can be polished, chromed, powder coated or left as-is

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Moroso Performance Aluminum Expansion Tank - E46 M3
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Moroso - Corporate Logo
T#:568945
Part#: 63793
In Stock at Vendor
$ 433.99 USD
Free Shipping
$ 433.99 USD
Free Shipping
If you have ever experienced a leaking plastic BMW expansion tank you will realize the value of this aluminum version straight away. Even if a failure has not happened to you, it's easy to tell this tank is much stronger and more durable than the plastic used in the stock design. The original BMW plastic tanks suffer from leaks and failures with no warning. While being lightweight and recyclable, the design and construction of the stock tank is just not up for reliable long-term use. Moroso coolant expansion tanks are all pressure tested for guaranteed leak-free operation. Features: Direct bolt-in replacement to stock, cracked, or discolored tanks Fabricated Aluminum for strength, factory tanks fail after repeated high heat situations & age No cutting of factory hoses is required and accepts the factory clip-on hose Included is a Moroso Part No. 63324 racing radiator cap that operates in the same pressure range as the factory cap The Moroso radiator cap mounts to a billet aluminum neck that will not strip out like plastic threaded necks Easy to read slight level is included
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Behr Radiator - E36
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Behr - Corporate Logo
T#:1196128
Part#: 17111723784
In Stock at Vendor
$ 298.35 USD
$ 298.35 USD
Brand new radiator equivalent to OE

Radiator
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Behr - Corporate Logo
T#:591360
Part#: 17111728905
In Stock at Vendor
$ 399.99

This product was last offered at the strikethrough price on
05-07-2026

$ 388.99 USD
Free Shipping on orders $49 and up
$ 388.99 USD
Free Shipping on orders $49 and up
Behr Replacement Radiator - More than likely, you are going to replace the radiator in your vehicle at least once. The joints where the cores meet the end tanks tend to get weak and are the first place to spring a leak. Impacts to the fins themselves can cause holes to form. Corrosion and clogging from the inside can make cooling less than effective and compromise coolant flow.
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Hella Radiator - Manual - E34
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Behr - Corporate Logo
T#:363371
Part#: 17111737760
In Stock at Vendor
$ 687.60 USD
$ 687.60 USD
Replace your leaking radiator
Moroso Aluminum Coolant Expansion Tank - E30 M3
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Moroso - Corporate Logo
T#:29666103
Part#: 63799
In Stock at Vendor
$ 459.99 USD
Free Shipping on orders $49 and up

The coolant expansion tank provides hot coolant with a place to travel, preventing pressure buildup within your cooling system. On many BMWs, this component is constructed from plastic. While cheap to replace and manufacture, a failed cooling tank can cause costly engine damage.

With this issue in mind, Moroso designed a high-quality replacement. Featuring TIG welded, 100% aluminum construction, this tank is sure to outperform it's factory counterpart.

Features:

Bolt-in replacement for stock cracked or discolored tanks Fabricated aluminum Features billet aluminum filler neck and integrated sight glass to monitor coolant level Can be polished, painted, powder coated or left as-is Moroso radiator cap (63320) included

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Behr Radiator - E60, E61, E63, E64
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Behr - Corporate Logo
T#:579569
Part#: 376755591
Back Ordered
$ 267.99 USD
$ 267.99 USD
Replace your leaking radiator
Moroso Performance Aluminum Expansion Tank - E36, Z3
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Moroso - Corporate Logo
T#:568887
Part#: 63791
In Stock
$ 445.99 USD
Free Shipping on orders $49 and up
$ 445.99 USD
Free Shipping on orders $49 and up
If you have ever experienced a leaking plastic BMW expansion tank you will realize the value of this aluminum version straight away. Even if a failure has not happened to you, it's easy to tell this tank is much stronger and more durable than the plastic used in the stock design. The original BMW plastic tanks suffer from leaks and failures with no warning. While being lightweight and recyclable the design and construction of the stock tank is just not up for reliable long term use. Moroso coolant expansion tanks are all pressure tested for guaranteed leak-free operation and utilizes the stock pressure cap to prevent excessive pressure in the cooling system from blowing off a radiator hose or seal! Features: Each cooling system expansion tank includes a 1/8 in. pipe overflow fitting at neck, a 1/4 in. NPT water intake bung, and a 1/2 in. bung at the bottom for plumbing a line to the radiator Rugged 6061-T6 billet aluminum filler necks welded to tank to withstand continuous removal and installation of cap 100% pressure tested to eliminate leaks Accepts a standard-size radiator cap
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REMOTE RADIATOR
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Behr - Corporate Logo
T#:33047035
Part#: 17117634565
In Stock at Vendor
$ 156.99

This product was last offered at the strikethrough price on
05-07-2026

$ 151.99 USD
Free Shipping on orders $49 and up
$ 151.99 USD
Free Shipping on orders $49 and up

E46 323/325/328/330 Manual, Z4 OEM Behr Radiator
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Behr - Corporate Logo
T#:338021
Part#: 17119071518
In Stock at Vendor
Starting at $ 249.99 USD
Starting at $ 249.99 USD
This is a BEHR brand (OEM supplier to BMW) replacement radiator for all 1999-2006 E46 3 series (non-M), including 323i, 323Ci, 328i, 328Ci, 325i, 325Ci, 330i, 330Ci, and Z4 2.5 and 3.0. Compare to BMW list price of $318! Save big, while still getting the highest quality radiator available for your BMW.

This radiator fits the follow BMWs: :
Only for Manual Transmission
1999-5/2005 E46 BMW 323i 323ci 325i 325ci 325xi 328i 328ci 330i 330ci 330xi - Not for cars with M56 engine

2003-2006 E85 BMW Z4 2.5i Z4 3.0i - M54 engine
2006-2008 E85 BMW Z4 M Roadster M Coupe
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Behr Radiator Replacement
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
For Automatic Vehicles only
Behr - Corporate Logo
T#:591355
Part#: 17117519211
In Stock at Vendor
$ 454.11 USD
$ 454.11 USD
Replace your faulty or worn radiator with this factory replacement
Radiator
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Behr - Corporate Logo
T#:594798
Part#: 17117576827
Ships in 1 day
$ 415.99 USD
Free Shipping on orders $49 and up
Replacement Radiator from Behr Hella


Radiator
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Behr - Corporate Logo
T#:594801
Part#: 17117570094
Ships on Jul 29, 2026
$ 374.99 USD
$ 374.99 USD
More than likely, you are going to replace the radiator in your vehicle at least once. The joints at where the cores meet the ends tend to get weak and are the first place to spring a leak. Impacts to the fins themselves can cause holes to form. Corrosion and clogging from the inside can make it less than effective. Replace your leaking unit with a factory replacement and get that jug of coolant out of your back seat.
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Radiator
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Behr - Corporate Logo
T#:594800
Part#: 17117605644
Ships on Jul 29, 2026
$ 362.99 USD
$ 362.99 USD
Replacement Radiator from Behr
Moroso Aluminum Coolant Expansion Tank
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Moroso - Corporate Logo
T#:29666104
Part#: 63850
In Stock at Vendor
$ 586.00 USD
Free Shipping on orders $49 and up

The coolant expansion tank provides hot coolant with a place to travel, preventing pressure buildup within your cooling system. On many BMWs, this component is constructed from plastic. While cheap to replace and manufacture, a failed cooling tank can cause costly engine damage.

With this issue in mind, Moroso designed a high-quality replacement. Featuring TIG welded, 100% aluminum construction, this tank is sure to outperform it's factory counterpart.

Features:

Key Benefits:

Direct bolt-in replacement for stock, 2 piece plastic tank Fabricated Aluminum for strength, factory tanks fail after repeated high heat situations & age Features billet aluminum mounting tab/bleeder assembly for strength and precision No cutting of factory hoses is required and accepts the factory clip-on hose Included is a Moroso (63324) racing radiator cap that operates in the same pressure range as the factory cap Moroso radiator cap mounts to a billet aluminum neck that will not strip out like plastic threaded necks Can be polished, chromed, or powder coated or left as-is

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Behr Radiator - E34
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Behr - Corporate Logo
T#:1195792
Part#: 17111723467
Back Ordered
$ 273.99

This product was last offered at the strikethrough price on
05-07-2026

$ 265.99 USD
$ 265.99 USD
OE replacement radiator