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BMW Cooling System Parts & Accessories for BMW Z Series E85/6 (2003-2008)

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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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Water Pump And Thermostat Kit - BMW N52 3.0L

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T#:17073598

Part#: 11537549476KT

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$ 318.83 USD

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Includes everything you may need to replace your water pump and thermostat.

Water Pump And Thermostat Kit

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T#:5376274

Part#: 11517586925TKT

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$ 337.56 USD

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Everything you need to replace your water pump and thermostat. The water pumps in these BMW models are known for failure near 80,000 miles is a very common issue often times leaving the owner stranded. The aftermarket kit offered provides a single stop for water pump and thermostat replacement needs to save the search and get you back on the road. Kit includes: Mahle-Behr thermostat Water pump Genuine BMW coolant thermostat to water pump hose Mounting hardware required for both the thermostat and water pump

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Complete Cooling System Overhaul Package - 2003-4/2004 Z4 2.5 3.0 ...

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T#:339100

Part#: TMS224320

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Starting at $ 454.24 USD

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Starting at $ 454.24 USD

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This is a customizable cooling system overhaul kit, which starts off with the basic radiator and water pump and can be configured to replace all the M54 common cooling system failure parts in one package. This cooling system package is for the 2003-2005 Z4 Roadster.

The Z4 cooling system is much like that of the sister 3 series. Several of the primary cooling components are prone to failure within 60k miles (or less in many cases). A failure in the cooling system can lead to overheating and catastrophic engine failure. Don't gamble your engine! By replacing these core items preventatively, such as the radiator & waterpump, you are defusing what could be a ticking cooling system time bomb. And if you've had a failure of one of these parts, now is the time to refresh your cooling system. Available with our kit is an OEM Behr radiator, an Original BMW water pump (with updated composite impeller), thermostat (complete with housing), radiator cap, new hoses, and other essential cooling parts.

Optional items (which can be added below):

Radiator cap

Major cooling hoses

Original BMW antifreeze

Upgrade the water pump to a Stewart EMP High Performance pump

Add a new coolant expansion tank (known for cracking)

Include a new coolant level sensor (known for failing / throwing "check coolant" messages)

Include a new coolant temp sensor (located in the lower radiator hose) (re-using the old sensor and seal may lead to a leak)

Add a new thermostat for an automatic transmission (located with the expansion tank).
This cooling system overhaul kit fits the following BMWs:
2003-2005 E85 BMW Z4 2.5i Z4 3.0i

Please put a check in the boxes next to the items you wish to order.

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Complete Cooling System Overhaul Package - 4/2004-2005 Z4 2.5 3.0 ...

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T#:339099

Part#: TMS16430

In Stock

Starting at $ 454.24 USD

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Starting at $ 454.24 USD

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This is a customizable cooling system overhaul kit, which starts off with the basic radiator and water pump and can be configured to replace all the M54 common cooling system failure parts in one package. This cooling system package is for the 2003-2005 Z4 Roadster.

The Z4 cooling system is much like that of the sister 3 series. Several of the primary cooling components are prone to failure within 60k miles (or less in many cases). A failure in the cooling system can lead to overheating and catastrophic engine failure. Don't gamble your engine! By replacing these core items preventatively, such as the radiator & waterpump, you are defusing what could be a ticking cooling system time bomb. And if you've had a failure of one of these parts, now is the time to refresh your cooling system. Available with our kit is an OEM Behr radiator, an Original BMW water pump (with updated composite impeller), thermostat (complete with housing), radiator cap, new hoses, and other essential cooling parts.

Optional items (which can be added below):

Radiator cap

Major cooling hoses

Original BMW antifreeze

Upgrade the water pump to a Stewart EMP High Performance pump

Add a new coolant expansion tank (known for cracking)

Include a new coolant level sensor (known for failing / throwing "check coolant" messages)

Include a new coolant temp sensor (located in the lower radiator hose) (re-using the old sensor and seal may lead to a leak)

Add a new thermostat for an automatic transmission (located with the expansion tank).
This cooling system overhaul kit fits the following BMWs:
4/2004-2005 E85 BMW Z4 2.5i Z4 3.0i

Please put a check in the boxes next to the items you wish to order.

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Thermostat

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T#:15511826

Part#: 11537549476

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Sale - Save 18% $ 84.99

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05-03-2026

$ 69.99 USD

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$ 84.99

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$ 69.99 USD

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Overheating your N52 or N54 engine can be detrimental to the longevity of your engine. We also recommend replacing your hardware 07119903851 x2

Genuine BMW Manual Transmission Crossmember

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T#:49465

Part#: 22316760531

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Sale - Save 5% $ 253.99

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 240.71 USD

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$ 253.99

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06-25-2026

$ 240.71 USD

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Genuine BMW Gearbox Support
This item fits the following BMW Chassis:
E85 Z4M,E46,E85 Z4,E86 Z4

Thermostat With Housing

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T#:26494584

Part#: 11537509227

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$ 49.99 USD

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$ 60.99

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$ 49.99 USD

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Genuine BMW Radiator Carrier - Right

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T#:45593

Part#: 17107524914

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Sale - Save 6% $ 68.99

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$ 64.66 USD

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$ 64.66 USD

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Genuine BMW Module Carrier

This item fits the following BMW Chassis:
E82 1M Coupe,E82,E89 Z4,E90,E92,E93

Fits BMW Engines including:
M57,N20,N51,N52,N52N,N54,N54T,N55,S65

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Genuine BMW Water Pump Pulley

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T#:4472

Part#: 11511436590

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Sale - Save 6% $ 73.99

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$ 69.65 USD

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SEE T#337981

Genuine BMW Radiator Mounting Plate for Expansion Tank - Z4

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T#:45825

Part#: 17112248408

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Sale - Save 6% $ 94.99

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$ 89.54 USD

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Genuine BMW Mounting Plate -
This item fits the following BMW Chassis:
E85,E86

Fits BMW Engines including:
M54,N52

Bremmen Parts Water Pipe Connector - E83, Z4

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T#:1195932

Part#: 17112248409

Ships on Jul 24, 2026

Sale - Save 3% $ 31.61

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$ 30.66 USD

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Located underneath the expansion tank

Bremmen Parts O-Ring

Found at the flange end of the upper thermostat hose

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T#:399143

Part#: 11537545278

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$ 4.07 USD

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Seals your cooling system

Bremmen Coolant Bleeder Screw - BMW E30 E36 E38 E39 E46 E83 E90 Z4 ...

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T#:640140

Part#: 17111712788

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$ 2.44 USD

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Plastic bleeder screw for cooling system is used to bleed air that would otherwise create an air pocket and lead to overheating. Includes o-ring seal.

Meyle Expansion Tank Cap

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T#:579357

Part#: 3148009004

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Sale - Save 40% $ 14.99

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$ 8.99 USD

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Replace worn or missing pieces.

Coolant Inlet Pipe

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T#:36032354

Part#: 11537516414

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Sale - Save 23% $ 18.99

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$ 14.68 USD

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$ 18.99

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Bremmen Parts Coolant Hose - E9X N52

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T#:38621425

Part#: 11537521049

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Sale - Save 23% $ 18.99

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$ 14.68 USD

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$ 14.68 USD

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Over the years and with exposure to extremely hot coolant, the coolant hoses in your vehicle can take a beating. Being made of reinforced rubber, these hoses can fail in a number of ways. Splitting at a hose clamp, swelling, cracking, and breaking are just a few of the ways this hose can leave you stranded. Replace it at the first sign of wear to keep your coolant in your engine.

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