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BMW Cooling System Parts & Accessories for BMW Z4 M Roadster S54 (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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OEM Style Hose Clamps

T#:338927

Part#: HOSE-CLAMPS

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This product was last offered at the strikethrough price on
06-13-2026

Starting at $ 3.87 USD

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$ 3.99

This product was last offered at the strikethrough price on
06-13-2026

Starting at $ 3.87 USD

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Hose clamps for radiator hoses, coolant hoses, vacuum hoses, or intake hoses. These hose clamps are the same style as your OEM hoses with a smooth inside band to prevent cutting into the hose material.

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Water Pump & Thermostat Kit - BMW Z3 Z4 S54 3.2L

T#:48194755

Part#: ZS54WPTKT2

Ships on Dec 3, 2026

$ 1,022.99

This product was last offered at the strikethrough price on
07-16-2026

$ 968.99 USD

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$ 968.99 USD

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It is important that your coolant system is serviced at regular intervals to ensure a long life. Over time, coolant systems are exposed to high temperatures and repeated thermal cycling, which causes warping, cracking, and hardening of plastics and rubber components in the coolant system. This can lead to coolant leaks and overheating, which can result in extensive engine damage if not resolved in a timely manner. This Water Pump & Thermostat kit helps to address a few of the most problematic parts, replacing these items entirely to keep your cooling system running optimally and efficiently.

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OEM Rein Expansion Tank Cap - BMW E32 E34 E36 E38 E39 E46 & More ...

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T#:340541

Part#: 17111742231

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$ 17.99 USD

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$ 17.99 USD

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This radiator expansion tank cap is used most BMW's from 1991-2006. It is a common failure item. When this item fails, it cannot hold pressure which results in your BMW overheating. If you are overhauling your coolant system, now is the time to consider preventative replacing this cap. It is also referred to as the coolant reservoir cap.

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Rein Coolant Bleeder Screw CHW1575 - Priced Each

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T#:591955

Part#: 17111712788

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$ 4.99 USD

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$ 4.99 USD

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Coolant Bleeder Screw is a critical component for maintaining your BMW’s cooling system. Designed to release trapped air from the coolant lines, this screw ensures efficient coolant flow and prevents overheating. Specifically engineered for BMW models, it enhances the overall performance and longevity of your engine by maintaining proper temperature regulation. Comes with O-Ring.

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Bav Auto Expansion Tank Cap - E36 E46 E34 E39 E32 E38 E65 X3 X5 Z4 ...

T#:640208

Part#: 17117639022

In Stock

Sale - Save 15% $ 13.99

This product was last offered at the strikethrough price on
06-03-2026

$ 11.89 USD

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Sale - Save 15%

$ 13.99

This product was last offered at the strikethrough price on
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$ 11.89 USD

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This radiator expansion tank cap is used most BMW's from 1991-2006. It is a common failure item. When this item fails, it cannot hold pressure which results in your BMW overheating. If you are overhauling your coolant system, now is the time to consider preventative replacing this cap. It is also referred to as the coolant reservoir cap. From 1974 to 2019, Bavarian Autosport was one of the premier vendors for BMW and MINI auto parts. We are happy to preserve the Bav Auto legacy by continuing to carry their high-quality products into the future. All Bav Auto parts will remain unchanged in design and sourced from the same OEM suppliers to ensure long-lasting reliability. We trust these parts, accessories, and upgrades so confidently that we back every Bavarian Autosport branded component with a 2-year warranty.

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BMW Brass Coolant Bleeder Screw - Priced Each

2X Entries For Our G87 M2 Sweepstakes!

T#:587673

Part#: 17111712788PRM

In Stock

$ 5.75

This product was last offered at the strikethrough price on
02-25-2026

$ 5.35 USD

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$ 5.35 USD

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Having an operational bleeder screw for your coolant system assures that when service is performed, all air pockets are removed. Having air pockets in your coolant system prevents your system from functioning properly. Your heat may not work as well and there is the potential for engine overheating if the air pocket is trapped behind the thermostat. Be sure that all of the air is bled out of your system with a new bleeder screw.

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Aluminum Screws for N52 N54 Water Pump

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T#:2253

Part#: 11510392553

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$ 7.13 USD

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$ 7.13 USD

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These aluminum water pump screws are single use and must be replaced each time they are removed. These are used on all 325i, 328i, and 330i with the BMW N51 N52 and N53 engines. They were also used on some early N54 engines that have rubber mounts on the water pump housing. Do not use these bolts if your N54 water pump has been replaced with a housing that does not have the rubber mounts.

In German, Rein means Pure. In the automotive industry the Rein name has quickly come to represent quality. With fitments for some of the world’s finest automobiles including BMW and Mini and guaranteed OE quality, Rein is a name you can trust.

This item fits the following BMWs:
2008+ E82 BMW 128i 135i
2007+ E9X BMW 325i 325xi 328i 328xi 330i 335i 335xi
2006+ E60 BMW 525i 525xi 528i 528xi 530i 530xi 535i 535xi
2006+ X3 BMW X3 3.0i X3 3.0si
2006+ Z4 BMW Z4 3.0i Z4 3.0si

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Bav Auto Temperature Sensor - BMW E39 E46 E9X E60 F01/02

T#:639833

Part#: 13621433076

In Stock

Sale - Save 20% $ 14.99

This product was last offered at the strikethrough price on
05-03-2026

$ 11.99 USD

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Sale - Save 20%

$ 14.99

This product was last offered at the strikethrough price on
05-03-2026

$ 11.99 USD

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This is the coolant temperature sensor used in many BMW models from the late-1990s to the mid-2010s. The engine computer relies on the coolant temp to set the fuel mapping for the engine. As the car warms up the computer changes the fuel mixture. If your car is running a bit rich (too much fuel) it could be because this sensor is failing and not sending the correct info to the computer. This sensor is located in a variety of places depending on the engine. But it's one of those easy replacement items 'while you're in there' when doing a water pump or thermostat replacement. From 1974 to 2019, Bavarian Autosport was one of the premier vendors for BMW and MINI auto parts. We are happy to preserve the Bav Auto legacy by continuing to carry their high-quality products into the future. All Bav Auto parts will remain unchanged in design and sourced from the same OEM suppliers to ensure long-lasting reliability. We trust these parts, accessories, and upgrades so confidently that we back every Bavarian Autosport branded component with a 2-year warranty.

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Radiator Support Bracket

2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!

T#:14122755

Part#: 17117514402

Special Order: No Guaranteed ETA

$ 8.99 USD

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$ 8.99 USD

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Mounts to top of radiator bracket, 2 per vehicle.

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