BMW Cooling System Parts & Accessories for BMW 5 Series E34 (1987-1995)

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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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Aluminum Thermostat Housing Kit - M50
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Active Autowerke - Corporate Logo
T#:397222
Part#: 14-009
In Stock
$ 56.99

This product was last offered at the strikethrough price on
06-18-2026

$ 52.99 USD
Limited Qty Sale
Free Shipping on orders $49 and up
$ 56.99

This product was last offered at the strikethrough price on
06-18-2026

$ 52.99 USD
Limited Qty Sale
Free Shipping on orders $49 and up
Plastic thermostat housing cracked on your M50?

Here are your choices: you can wait for the plastic factory thermostat housing cover to break and cause major overheating. (Even with a new stock cover, it won’t take long.) Or you can install a thoughtfully engineered all-aluminum thermostat housing cover from Active Autowerke and never experience this type of failure again. Currently there is no factory upgraded part to this problem. This is an aluminum extruded part that has all of the openings machine properly to fit like factory; from the mounting bolt holes, the seating of the thermostat to the sealing opening for the ORANGE gasket. Forged to exact factory tolerances, everything fits and this unit is a true easy bolt-on – especially suited for racing or load conditions like heavy traffic, where engine temp can rise rapidly. The housing is guaranteed never to break from overheating or over-tightening, and its CNC machined surface ensures a precise seat.

Unit comes complete with a new ORANGE sealing gasket; a new thermostat is recommended but not included.
For hotter climates, a 71 degree thermostat is recommended over the 82 degree unit.

Anything and everything BMW is the mantra at Active Autowerke. Since 1981 they have been serving the BMW community with custom turbocharger kits to a myriad of other innovative and inspiring performance parts.
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Bav Auto Expansion Tank Cap - E36 E46 E34 E39 E32 E38 E65 X3 X5 Z4 ...
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Bavarian Autosport - Corporate Logo
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
Free Shipping on orders $49 and up
Sale - Save 15%
$ 13.99

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

$ 11.89 USD
Free Shipping on orders $49 and up
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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Water Temperature Sensor
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Beru - Corporate Logo
T#:596874
Part#: 12621288158
Ships in 1-2 days
$ 44.99 USD
Free Shipping on orders $49 and up
$ 44.99 USD
Free Shipping on orders $49 and up
M14x1.5 Thread. Your vehicle is equipped with numerous gauges to allow you to have a better idea of what is going on under the hood. By monitoring these gauges, you can prevent premature engine damage due to low oil pressure or high coolant temperatures. If one isn't functional though, you are in the dark as far as that system goes. One of the most vital is coolant temperature. Replace the sensor to get your gauge working properly again.
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