BMW Cooling System Parts & Accessories for BMW Z3 (1996-2002)

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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 Wahler Thermostat With Housing - E46 E53 E60 E83 M54
For vehicles with production date from 09/1998
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Wahler - Corporate Logo
T#:341054
Part#: 11537509227
In Stock
$ 69.99 USD
Free Shipping on orders $49 and up
$ 69.99 USD
Free Shipping on orders $49 and up
Stop leaks before they start with this new Thermostat With Housing from Wahler. Despite the fact that most BMW models are brilliant, most have common issues that can plague you during your ownership of the car. This part is one of those issues, as they are known to crack over time. This replacement part is perfect stop a crack and possibly a leak before it starts.
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OEM Wahler 80 Degree Thermostat - E46 M3, MZ3 S54, Z4 M
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Wahler - Corporate Logo
T#:360524
Part#: 11531318274
In Stock at Vendor
$ 105.59

This product was last offered at the strikethrough price on
06-25-2026

$ 80.99 USD
Free Shipping
$ 80.99 USD
Free Shipping
Replacement 80* Celcius thermostat for E46 M3, Z3M w S54 engine, Z4M. The thermostat can be replaced on the E46 M3 without removing the water pump. This can save you money if the pump still has life left on it but the thermostat needs to be done now. Symptoms of a bad thermostat include an erratic temp gauge and a fault code. When replacing the thermostat, there are three o-rings that will likely need to be replaced between the thermostat and the water pump housing, and two on the coolant tube going to the head. We also recommend new hoses, clamps, and BMW coolant. Replacement should take about one hour.
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Wahler Thermostat - 88�C - E30, E34, E36, Z3
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Wahler - Corporate Logo
T#:369466
Part#: 11537511580
In Stock
$ 52.99

This product was last offered at the strikethrough price on
06-19-2026

$ 51.99 USD
Free Shipping on orders $49 and up
$ 51.99 USD
Free Shipping on orders $49 and up
Common point of failure in the cooling system.

Moroso Performance Aluminum Expansion Tank - E36, Z3
For vehicles with a production date before 09/1998
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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Wahler Thermostat O-Ring - E46, Z3, Z4
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Wahler - Corporate Logo
T#:362366
Part#: 11531318402
Ships in 4 Business Days
$ 6.17 USD
Free Shipping on orders $49 and up
BMW does not include a o-ring with their new thermostats
Wahler Performance Thermostat - 75*C - M42, M50, M52, S50, S52 ...
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Wahler - Corporate Logo
T#:54388511
Part#: 11537511580
In Stock at Vendor
New Item
$ 59.99 USD
Free Shipping on orders $49 and up
75°C variant is specifically calibrated for track racing, forced-induction builds, or hot-climate competitive environments