BMW Cooling System Parts & Accessories for BMW 5 Series E39 (1996-2003)

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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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Basic Cooling System Service Kit - E39 540i (09/1998+)
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T#:557233
Part#: E39540BCKT2
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Just like the rest of your vehicle's major systems, the cooling system must also be addressed periodically to ensure proper cooling and component reliability. Plastic and rubber components become brittle and prone to splitting or cracking after long periods of heating and cooling cycles, especially in colder climates! The coolant itself can degrade or become contaminated, leading to potential corrosion or freezing issues. Finally, thermostats and sensors can fail completely, preventing proper cooling and/or coolant temperature readings to become inaccurate.

To make sure you are not left stranded on the side of the road with an overheated engine, we have put together this Basic Cooling System Service kit. This kit contains all of the most-likely-to-fail components, giving you peace of mind knowing your engine will continue to run cool for another 60,000+ miles.

See kit contents below for all included components.

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Packaged by Turner - Corporate Logo
T#:557232
Part#: E39M5XBCKT
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Just like the rest of your vehicle's major systems, the cooling system must also be addressed periodically to ensure proper cooling and component reliability. Plastic and rubber components become brittle and prone to splitting or cracking after long periods of heating and cooling cycles, especially in colder climates! The coolant itself can degrade or become contaminated, leading to potential corrosion or freezing issues. Finally, thermostats and sensors can fail completely, preventing proper cooling and/or coolant temperature readings to become inaccurate.

To make sure you are not left stranded on the side of the road with an overheated engine, we have put together this Basic Cooling System Service kit. This kit contains all of the most-likely-to-fail components, giving you peace of mind knowing your engine will continue to run cool for another 60,000+ miles.

See kit contents below for all included components.

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T#:557221
Part#: E39528BCKT
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Just like the rest of your vehicle's major systems, the cooling system must also be addressed periodically to ensure proper cooling and component reliability. Plastic and rubber components become brittle and prone to splitting or cracking after long periods of heating and cooling cycles, especially in colder climates! The coolant itself can degrade or become contaminated, leading to potential corrosion or freezing issues. Finally, thermostats and sensors can fail completely, preventing proper cooling and/or coolant temperature readings to become inaccurate.

To make sure you are not left stranded on the side of the road with an overheated engine, we have put together this Basic Cooling System Service kit. This kit contains all of the most-likely-to-fail components, giving you peace of mind knowing your engine will continue to run cool for another 60,000+ miles.

See kit contents below for all included components.

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Packaged by Turner - Corporate Logo
T#:338704
Part#: TMS14417
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This is a compete cooling system overhaul kit, which includes all the common cooling system failure parts bundled into a complete package. This cooling system package is for the 1999-2003 540i with the M62TU VAN0S 4.4-liter engine. This package applies to cars equipped with either the manual or automatic transmission (select the appropriate parts in the menu below).

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 thermostat housing, radiator, and 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 entire cooling system. Our bundled package includes the following:
  • OEM Behr radiator (select for manual or automatic transmission)
  • OEM water pump (choose either the metal or composite impeller)
  • OE BMW coolant temp sensor (located in the water pump housing)
  • OEM Behr thermostat with housing and sensor
  • OEM Behr expansion tank with cap
  • OE BMW upper and lower radiator hoses with expansion tank hose
    Optional items (which can be added below):
    - OE BMW antifreeze
    - Add a new coolant level sensor (known for failing / throwing "check coolant" messages)
    - Replace the heat exchanger coolant lines for the automatic transmission
    - Add a new fan clutch

    Buy as a package and save $$$!

    This cooling system overhaul kit fits the following BMWs:
    1999-2003 E39 BMW 540i
    1999-2001 E38 BMW 740i 740il
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    Packaged by Turner - Corporate Logo
    T#:338705
    Part#: TMS16592
    Ships in 3 Business Days
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    The oil cooler/heat exchanger for the automatic transmission is one of the most overlooked sections of the 540i and 740i cooling system. The cooler (heat exchanger) is a part of the overall cooling system and uses coolant circulated from the regular cooling system to cool the transmission oil running through this small cooling block. Some of the hoses are shared with the rest of the cooling system as well. The E38/E39 heat exchanger is located along the driver's side frame rail and is accessed from the wheel well. We recommend servicing or cleaning the heat exchanger along with any cooling system overhaul. Or if you're having transmission faults (especially for temperature) you may want to clean the transmission cooler anyway and these hoses will be a nice finishing touch.

    Replacing or cleaning the heat exchanger components could lead to better shifting of the automatic as the cooler itself can become clogged. If you're experiencing harder or hesitating shifts, and the internal transmission temperature is rising without being regulated, the components in this system are the likely cause. Staying on top of the cooling needs of the transmission will help prevent a very costly transmission repair in the future. These hoses are easily replaced and you can clean the heat exchanger easily with brake cleaner and some brushes.

    Included in this handy package are:
  • 11531711381 - transmission cooling hose from water pump to radiator (with t-connector)
  • 11531711385 - transmission cooling hose from radiator to cooler
  • 11531711384 - transmission cooling hose from cooler to water pump
  • 11537511207 - transmission cooling hose from cooler to chassis
  • hose clamp
  • o-ring


    This hose set fits the following BMWs:
    1999-2003 E39 BMW 540i
    1999-2001 E38 BMW 740i 740il
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    High Performance Metal Water Pump & Pulley Kit - M54
    10X Entries Into Our F80 M3 Sweepstakes
    Packaged by Turner - Corporate Logo
    T#:55749612
    Part#: 888010330KT3
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    Packaged by Turner - Corporate Logo
    T#:557230
    Part#: E39540BCKT
    Ships in 2 Business Days
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    Just like the rest of your vehicle's major systems, the cooling system must also be addressed periodically to ensure proper cooling and component reliability. Plastic and rubber components become brittle and prone to splitting or cracking after long periods of heating and cooling cycles, especially in colder climates! The coolant itself can degrade or become contaminated, leading to potential corrosion or freezing issues. Finally, thermostats and sensors can fail completely, preventing proper cooling and/or coolant temperature readings to become inaccurate.

    To make sure you are not left stranded on the side of the road with an overheated engine, we have put together this Basic Cooling System Service kit. This kit contains all of the most-likely-to-fail components, giving you peace of mind knowing your engine will continue to run cool for another 60,000+ miles.

    See kit contents below for all included components.

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    Cooling System overhaul Kit - E39 528i From 09/1998
    10X Entries Into Our F80 M3 Sweepstakes
    Packaged by Turner - Corporate Logo
    T#:554546
    Part#: 11517527910KT17
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    This is a compete cooling system overhaul kit, which includes all the common cooling system failure parts bundled into a complete package. This cooling system package is for the E39 528i with the M52 engine. 

    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 thermostat housing, radiator, and 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 entire cooling system. Keep on top of the cooling needs of your engine for your own piece of mind. Potential buyers also see the upside of a properly maintained car with receipts. 

     

    This kit fits the following BMWs:

    09/1998 - 2000 E39 528i

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    Thermostat Replacement Kit - E39 540i 1999-2003
    10X Entries Into Our F80 M3 Sweepstakes
    Packaged by Turner - Corporate Logo
    T#:554085
    Part#: 11531436386KT3
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    When it comes time to replace your thermostat, be sure you have everything you need. This kit includes everything you need to replace your thermostat, including the thermostat.

    Kit includes:

    • Rein thermostat
    • Thermostat mounting hardware
    • 1 liter of coolant

     

    This item fits the following BMWs: 
    1999-2003  E39 BMW  540i 
     

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    Thermostat Replacement Kit - E39 540i 1996-1998
    10X Entries Into Our F80 M3 Sweepstakes
    Packaged by Turner - Corporate Logo
    T#:554083
    Part#: 11531437526KT2
    Ships in 2 Business Days
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    When it comes time to replace your thermostat, be sure you have everything you need. This kit includes everything you need to replace your thermostat, including the thermostat.

    Kit includes:

    • Behr thermostat with O-ring
    • Thermostat mounting hardware
    • 1 Gallon BMW coolant

     

    This item fits the following BMWs: 

    1997-1998  E39 BMW  540i

     

     

    When it comes time to replace your thermostat, be sure you have everything you need. This kit includes everything you need to replace your thermostat, including the thermostat.

    Kit includes:

    • Behr thermostat with O-ring
    • Thermostat mounting hardware
    • 1 Gallon BMW coolant
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    Packaged by Turner - Corporate Logo
    T#:338706
    Part#: TMS14416
    Back Ordered
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    This is a compete cooling system overhaul kit, which includes all the common cooling system failure parts bundled into a complete package. This cooling system package is for the 1997-1998 540i with the M62 4.4-liter engine (non-VAN0S). This package applies to cars equipped with either the manual or automatic transmission (select the appropriate parts in the menu below).

    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 thermostat housing, radiator, and 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 entire cooling system.

    Basic Kit Contents:
    1711702969, radiator (OEM Behr)
    11510393340, water pump (OEM)
    13621703993, coolant temp sensor (located in the water pump housing)
    11531437526, thermostat with housing and sensor (OEM Behr/Hella)
    11531745595, upper radiator hose (OEM)
    11531741409, lower radiator hose (OEM)
    11531741404, expansion tank hose (OEM)
    17111741167, expansion tank (OEM Behr)
    17111742231, expansion tank cap (OEM Behr)

    Cooling Kit Options:
    540 Water Pump Options
    (click to expand)
    There are three versions of the water pump for the early 1997-1998 540i: OEM plastic impeller, updated metal impeller, and the more recently updated composite impeller. We recommend either the metal or composite impeller. These are what we use the most in our shop and what our technicians are comfortable with. On more recent models, BMW has used the composite impeller as original. There doesn't seem to be evidence of the plastic failing on this design (it did on the E36 3-series) but we feel most comfortable with the other options. Both the metal and composite manufacturers are OEM for BMW.

    Use the options below to build your cooling package.

    Buy as a package and save $$$!

    This cooling system overhaul kit fits the following BMWs:
    1997-1998 E39 BMW 540i
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    Bav Auto Thermostat With Aluminum Housing - M52TU M54
    For vehicles with production date from 09/1998
    10X Entries Into Our F80 M3 Sweepstakes
    Bavarian Autosport - Corporate Logo
    T#:12544802
    Part#: 11531437040
    In Stock
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    $ 84.99 USD
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    The plastic thermostat cover in your BMW is a known point of failure. Throughout years of repeated contact with hot coolant, the plastic can crack and cause massive coolant leaks and potential overheating. Eliminate one of the weak links in your cooling system with a replacement aluminum thermostat housing. By installing this aluminum unit, you have no worries as far as plastic housing cracks go
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    Bav Auto Coolant Expansion Tank - E36 E39 Z3 M50 M52 S50 S52 ...
    For vehicles with production date up to 08/1998
    10X Entries Into Our F80 M3 Sweepstakes
    Bavarian Autosport - Corporate Logo
    T#:638094
    Part#: 17111723520
    In Stock
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    Replace your old expansion tank to prevent potential failure or leaks. Includes a brand new coolant level sensor. 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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    Thermostat With Housing - 90C
    For vehicles with a production date from 09/1998
    10X Entries Into Our F80 M3 Sweepstakes
    Bremmen Parts - Corporate Logo
    T#:598978
    Part#: 11531436386
    In Stock
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    A thermostat that opens sooner promotes better cooling in your vehicle. Running a lower temperature thermostat will keep everything much cooler. Keeping the engine cooler will help reduce and improve the life of the seals in your engine, saving you time and money, while also help increase engine performance. A tune might be required to gain the most from this modification, as well as to get your car's ECU accustomed to seeing lower temperatures.
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    Bavarian Autosport Water Pipe - E46 E39 Z4 Z3 (M52TU, M54)
    10X Entries Into Our F80 M3 Sweepstakes
    Bavarian Autosport - Corporate Logo
    T#:638085
    Part#: 11537502525
    In Stock
    Sale - Save 20% $ 50.99

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    This plastic water pipe is positioned directly underneath your intake manifold. Due to its plastic construction, it is notorious for catastrophic failure. Rapid cooling loss and overheating are both direct results of this failure, posing permanent and lasting damage to the engine.

    Replace your cracked/broken coolant pipe with this high-quality Bavarian Autosport component to ensure long-term reliability and perfect fitment.

    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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    Bav Auto Heater Inlet Pipe - E46 E39 E53 E83 E85 Z3
    10X Entries Into Our F80 M3 Sweepstakes
    Bavarian Autosport - Corporate Logo
    T#:638080
    Part#: 11531705210
    In Stock
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    This is the plastic heater inlet pipe that connects the cylinder head to the heater inlet on cars with the M52 or M54 engine. The plastic on this hose becomes brittle over time and eventually leads to failure. Replace yours with a brand new Bav Auto Heater inlet pipe to prevent catastrophic failure.
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    Thermostat With Housing
    10X Entries Into Our F80 M3 Sweepstakes
    Bremmen Parts - Corporate Logo
    T#:26494584
    Part#: 11537509227
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    Coolant Expansion Tank
    10X Entries Into Our F80 M3 Sweepstakes
    Bremmen Parts - Corporate Logo
    T#:36032353
    Part#: 17111741167
    In Stock
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    Coolant Expansion Tank - 17111436381
    For vehicles with production date from 09/1998
    10X Entries Into Our F80 M3 Sweepstakes
    Bremmen Parts - Corporate Logo
    T#:36303285
    Part#: 17111436381
    In Stock
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    BMW E39 Coolant Expansion Tank is an essential component designed to maintain the proper coolant level in your vehicle's cooling system. Manufactured with high-quality materials, this expansion tank ensures reliable performance and durability, preventing engine overheating by accommodating the expansion of coolant as it heats up. The kit includes a level sensor and cap, providing everything needed for a seamless installation. This expansion tank is specifically engineered to meet the exact specifications of your BMW E39, offering a perfect fit and optimal functionality.

    Complete Kit: Includes level sensor and cap for easy installation. High-Quality Construction: Built with durable materials for long-lasting performance. Prevents Overheating: Helps manage coolant expansion, ensuring engine protection. Exact Fit: Designed to meet the precise specifications of your BMW E39. Enhanced Reliability: Ensures proper coolant level maintenance for optimal cooling system function.

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    E39 Upper Radiator Hose - 11531705223
    For vehicles with production date from 09/1998
    10X Entries Into Our F80 M3 Sweepstakes
    Bremmen Parts - Corporate Logo
    T#:36100154
    Part#: 11531705223
    In Stock
    Sale - Save 50% $ 46.99

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    Over time, prolonged exposure to high-temperature coolant can take a toll on your vehicle's hoses. Made from reinforced rubber, these hoses are prone to wear and failure in various ways, including splitting at hose clamps, swelling, cracking, or breaking. Any of these issues can lead to coolant loss and potentially leave you stranded. Replacing your hoses at the first sign of wear is essential to maintaining a properly functioning cooling system.

    This replacement hose is designed with the correct diameter, bends, and length for a precise fit, making it an ideal solution for swelled or damaged hoses. With straightforward installation, this hose provides peace of mind, whether you're embarking on a long road trip or simply commuting to work.

    When replacing your radiator hose, some coolant loss is unavoidable. Browse our website to find the exact replacement coolant and other parts for your vehicle, delivered straight to your door. Don’t forget to order a new thermostat housing as well—factory plastic units often crack or warp during removal, and replacing them ensures a complete and reliable repair.

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    Radiator Hose - Lower
    10X Entries Into Our F80 M3 Sweepstakes
    Bremmen Parts - Corporate Logo
    T#:39768309
    Part#: 11531741409
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    Bav Auto Coolant Temperature Sensor - M52/S52, M62, M73, M54, S62 ...
    Located on water pump housing For vehicles with production date from 09/1998
    10X Entries Into Our F80 M3 Sweepstakes
    Bavarian Autosport - Corporate Logo
    T#:639828
    Part#: 13621703993
    Ships on Sep 28, 2026
    Sale - Save 20% $ 20.99

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    This is the coolant temperature sensor used in many BMW models from the mid-1990s to the mid-2000s. 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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    Bremmen Auxiliary Fan Temperature Switch - E46 E39 E9X E60 E70 E53 ...
    For vehicles with production date from 09/1998
    10X Entries Into Our F80 M3 Sweepstakes
    Bremmen Parts - Corporate Logo
    T#:640141
    Part#: 13621433077
    In Stock
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    The auxiliary fan switch activates the auxiliary cooling fan to provide additional cooling under high heat loads, and when the car is stationary
    E39 Lower Radiator Hose - 11531705224
    For vehicles with production date from 09/1998
    10X Entries Into Our F80 M3 Sweepstakes
    Bremmen Parts - Corporate Logo
    T#:36100127
    Part#: 11531705224
    In Stock
    Sale - Save 50% $ 36.99

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

    $ 18.50 USD
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    $ 36.99

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

    $ 18.50 USD
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    Over time, and with prolonged exposure to high-temperature coolant, the hoses in your vehicle's cooling system endure significant wear and tear. Made from reinforced rubber, these hoses can fail in various ways, including splitting near hose clamps, swelling, cracking, or even rupturing completely. Any of these failures can lead to coolant loss and leave you stranded. Replace your coolant hoses at the first sign of wear to ensure your engine stays properly cooled and running reliably.
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    Bav Auto Coolant Level Sensor - BMW E36 E39 M50/52 S50/52
    For vehicles with production date up to 09/1998
    10X Entries Into Our F80 M3 Sweepstakes
    Bavarian Autosport - Corporate Logo
    T#:639793
    Part#: 61318360855
    In Stock
    Sale - Save 19% $ 20.99

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

    $ 16.99 USD
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    $ 20.99

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

    $ 16.99 USD
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    This is the sensor / sending unit that notifies the computer if your coolant level is low. When this fails, it can give a false indication of low coolant -- or worse, not inform you of a low coolant situation that could potentially cause overheating. 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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    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
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    $ 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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    Meyle Expansion Tank Cap
    5X Entries Into Our F80 M3 Sweepstakes
    We Price Match - Give Us A Call or Chat!
    Meyle - Corporate Logo
    T#:579357
    Part#: 3148009004
    In Stock
    Sale - Save 40% $ 14.99

    This product was last offered at the strikethrough price on
    05-15-2026

    $ 8.99 USD
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    $ 14.99

    This product was last offered at the strikethrough price on
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    $ 8.99 USD
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    Replace worn or missing pieces.

    Thermostat With Housing - 105C
    10X Entries Into Our F80 M3 Sweepstakes
    Bremmen Parts - Corporate Logo
    T#:15511816
    Part#: 11531436386
    Ships in 8 Business Days
    Sale - Save 4% $ 30.99

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

    $ 29.67 USD
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    Sale - Save 4%
    $ 30.99

    This product was last offered at the strikethrough price on
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    A thermostat that opens sooner promotes better cooling in your vehicle. Running a lower temperature thermostat will keep everything much cooler. Keeping the engine cooler will help reduce and improve the life of the seals in your engine, saving you time and money, while also help increase engine performance. A tune might be required to gain the most from this modification, as well as to get your car's ECU accustomed to seeing lower temperatures.
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    Bremmen Parts - Corporate Logo
    T#:640149
    Part#: 11521712058
    In Stock
    Sale - Save 22% $ 23.99

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

    $ 18.76 USD
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    $ 23.99

    This product was last offered at the strikethrough price on
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    $ 18.76 USD
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    This fan is driven by the serpentine belt, engaged by the fan clutch. If you have bad motor mounts, it's quite common for the blades of this fan to make contact with the radiator or radiator shroud, essentially self-destructing the fan into many pieces. Be sure to get a new fan clutch, while you are replacing this.
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