BMW Cooling System Parts & Accessories for BMW E90 M3 S65 4.0L

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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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Goldenwrench Supply Co - Corporate Logo
T#:641289
Part#: FXXCET-R
In Stock
$ 65.00 USD
Free Shipping
$ 65.00 USD
Free Shipping
Give the plain plastic factory coolant caps an upgrade with the brand new BLACKLINE Performance Coolant Expansion Tank Cap Cover from Goldenwrench. Each cap is CNC formed from T6 Aluminum and anodized in a limited release race inspired red color. All logos and decorations are finalized through a precision 3D milling process, machined into each cap for the ultimate premium finish. The BLACKLINE Performance Billet Coolant Expansion Tank Cap Cover will fit most BMW vehicles equipped with the N55, S55, S63, and S65 engine with the large coolant tank found in the following vehicles E90/E91/E92 M3 LCI, F22 M235i, F87 M2/M2 Competition, F80 M3, F82 M4, F10/F90 M5, and more (check your coolant cap ensuring that it is the same shape as seen in the product photos). Each kit comes with a Billet Coolant Expansion Tank Cap Cover, and an Installation Instruction Card. This is a not a full cap replacement. The Billet Cap Cover affixes to the top of your factory coolant cap installing easily in minutes.
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Goldenwrench Supply Co - Corporate Logo
T#:5691129
Part#: FXXCET-B
In Stock
$ 65.00 USD
Free Shipping
$ 65.00 USD
Free Shipping
Give the plain plastic factory coolant caps an upgrade with the brand new BLACKLINE Performance Coolant Expansion Tank Cap Cover from Goldenwrench. Each cap is CNC formed from T6 Aluminum and anodized in a limited release race inspired blue color. All logos and decorations are finalized through a precision 3D milling process, machined into each cap for the ultimate premium finish. The BLACKLINE Performance Billet Coolant Expansion Tank Cap Cover will fit most BMW vehicles equipped with the N55, S55, S63, and S65 engine with the large coolant tank found in a variety of M vehicles(check your coolant cap ensuring that it is the same shape as seen in the product photos). Each kit comes with a Billet Coolant Expansion Tank Cap Cover, and an Installation Instruction Card. This is a not a full cap replacement. The Billet Cap Cover affixes to the top of your factory coolant cap installing easily in minutes.
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Vargas Turbo Technologies - Corporate Logo
T#:7530036
Part#: COOLANTCAPBLUE
In Stock
$ 79.99 USD
Free Shipping
$ 79.99 USD
Free Shipping
VTT is proud to offer their billet replacement for the factory plastic Coolant Reservoir cap. This cap does away with the weak plastic cap while adding some pop, and color to your engine bay. This coolant cap retains ALL of the factory provisions by simply allowing you to snap the factory pressure-relief into the new Billet Cap. VTT also designed these caps to complement their N5X Billet Oil caps, N5XBillet Oil filter housing caps, and Billet Power Steering cap, so all 4 will have the same design. These caps are offered in 4 colors – Red, Black, Blue, and Clear anodized Replaces Genuine BMW Reservoir Cap # 17117639020 Note: Fitment includes 99% of all BMW with a coolant Reservoir tank from the E series forward, meaning then fit even the brand New G8X M3/4 with the S58, all B58, etc. If your BMW is an E90 or newer this cap most likely will fit
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Do88 - BigPack BMW M3 E90/E92 DKG DCT
For BMW M3 E90 and E92 models with DKG/DCT transmission
DO88 - Corporate Logo
T#:34885395
Part#: BIG-M3-DCT
In Stock
$ 3,041.99

This product was last offered at the strikethrough price on
10-03-2026

$ 2,799.99 USD
Free Shipping
$ 2,799.99 USD
Free Shipping

Do88 - BigPack BMW M3 E90/E92 DKG DCT offers a premium solution for BMW enthusiasts seeking optimal cooling performance for their high-performance M3 models. Designed specifically for the BMW M3 E90 and E92 equipped with the DKG/DCT transmission, this complete cooling package by Do88 provides significant improvements in engine and transmission temperatures, ensuring peak performance and reliability under extreme conditions. Ideal for both street and track applications, this package offers unparalleled benefits for any driver looking to enhance their BMW’s performance.

Key Features:

Comprehensive cooling solution designed for BMW M3 E90 and E92 models with DKG/DCT transmission Includes - M3 engine oil cooler, M3 DCT / DKG oil cooler, M3 power steering cooler, M3 radiator Significantly reduces heat levels, allowing for sustained performance in intense driving scenarios Direct-fit design for straightforward installation without extensive modifications Engineered to withstand high-performance demands for both street and track use The Do88 BigPack BMW M3 E90/E92 DKG DCT cooling kit is a top choice for enthusiasts and professional drivers who need reliable and robust performance. Designed with precision and superior materials, this package ensures your BMW M3 remains cool under pressure, making it an essential upgrade for any Turner Motorsport enthusiast aiming to achieve the ultimate driving experience.

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DO88 - Corporate Logo
T#:13891856
Part#: OC100
In Stock at Vendor
$ 782.99 USD
Free Shipping
$ 782.99 USD
Free Shipping
The Beloved S65 V8 from BMW is well known and claimed to be one of the best engines ever introduced by the brand, but just like any other powertrain, it comes with its own set of issues. One of these issues is cooling issues. The team at DO88 took this opportunity to create and engineer a newly upgraded oil cooler to eliminate all of the previous issues. Boasting a 65% increase in core volume, a 59% larger active cooling area, and a 13.9% higher oil volume, this cooler definitely outperforms its OE counterpart. Nonetheless, this oil cooler is the perfect upgrade to your E9X M3!
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DO88 - Corporate Logo
T#:13891817
Part#: WC190
In Stock at Vendor
$ 712.00 USD
Free Shipping
$ 712.00 USD
Free Shipping
The team at DO88 has vigorously tested this radiator to deliver peak performance with the peace of mind of quality for your N55 engine. They guarantee reliability and endurance in all situations to let your car breathe better than before! Boasting a 14% increase in core volume and 8% lower coolant temps, this upgrade is a no-brainer for petrol heads like us. Keeping core temperatures low eliminates the risk of heat soak leading to overheating giving you max performance at any given moment. no compromise has been made at DO88 leaving you with one of the best radiator options on the market!
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Vargas Turbo Technologies - Corporate Logo
T#:7530034
Part#: COOLANTCAPRED
In Stock
$ 79.99 USD
Free Shipping
$ 79.99 USD
Free Shipping
VTT is proud to offer their billet replacement for the factory plastic Coolant Reservoir cap. This cap does away with the weak plastic cap while adding some pop, and color to your engine bay. This coolant cap retains ALL of the factory provisions by simply allowing you to snap the factory pressure-relief into the new Billet Cap. VTT also designed these caps to complement their N5X Billet Oil caps, N5XBillet Oil filter housing caps, and Billet Power Steering cap, so all 4 will have the same design. These caps are offered in 4 colors – Red, Black, Blue, and Clear anodized Replaces Genuine BMW Reservoir Cap # 17117639020 Note: Fitment includes 99% of all BMW with a coolant Reservoir tank from the E series forward, meaning then fit even the brand New G8X M3/4 with the S58, all B58, etc. If your BMW is an E90 or newer this cap most likely will fit
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Goldenwrench Supply Co - Corporate Logo
T#:641288
Part#: FXXCET
In Stock
$ 65.00 USD
Free Shipping
$ 65.00 USD
Free Shipping
Give the plain plastic factory coolant caps an upgrade with the brand new BLACKLINE Performance Coolant Expansion Tank Cap Cover from Goldenwrench. Each cap is CNC formed from T6 Aluminum and anodized with an Anthracite Gray color to compliment the factory engine cover. All logos and decorations are finalized through a precision 3D milling process, machined into each cap for the ultimate premium finish. The BLACKLINE Performance Billet Coolant Expansion Tank Cap Cover will fit most BMW vehicles equipped with the N55, S55, S63, and S65 engine with the large coolant tank found in the following vehicles E90/E91/E92 M3 LCI, F22 M235i, F87 M2/M2 Competition, F80 M3, F82 M4, F10/F90 M5, and more (check your coolant cap ensuring that it is the same shape as seen in the product photos). Each kit comes with a Billet Coolant Expansion Tank Cap Cover, and an Installation Instruction Card. This is a not a full cap replacement. The Billet Cap Cover affixes to the top of your factory coolant cap installing easily in minutes.
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VTT Billet Coolant Reservoir Cap - Anodized Clear - Most BMWs 2006+ (...
This coolant cap retains ALL of the factory provisions by simply allowing you to snap t...
2X Entries Into Our F80 M3 Sweepstakes
Vargas Turbo Technologies - Corporate Logo
T#:7530035
Part#: COOLANTCAPRAW
Ships in 4 Business Days
$ 78.99 USD
Free Shipping
$ 78.99 USD
Free Shipping
VTT is proud to offer their billet replacement for the factory plastic Coolant Reservoir cap. This cap does away with the weak plastic cap while adding some pop, and color to your engine bay. This coolant cap retains ALL of the factory provisions by simply allowing you to snap the factory pressure-relief into the new Billet Cap. VTT also designed these caps to complement their N5X Billet Oil caps, N5XBillet Oil filter housing caps, and Billet Power Steering cap, so all 4 will have the same design. These caps are offered in 4 colors – Red, Black, Blue, and Clear anodized Replaces Genuine BMW Reservoir Cap # 17117639020 Note: Fitment includes 99% of all BMW with a coolant Reservoir tank from the E series forward, meaning then fit even the brand New G8X M3/4 with the S58, all B58, etc. If your BMW is an E90 or newer this cap most likely will fit
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DO88 - Corporate Logo
T#:13891852
Part#: OC120
In Stock at Vendor
$ 646.99 USD
Free Shipping
$ 646.99 USD
Free Shipping
Boasting a 261% increase in core volume, a 100% increase in active cooling area, and a 100% larger oil volume, this power steering oil cooler is an absolute no-brainer. The second one installs wider wheels or stickier tires, the steering servo motor will start getting a run for its money, leaving the opportunity for heat soak. With our of development and rigorous testing, this oil cooler suits track use just as much as street use and is the perfect upgrade for your vehicle!
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Active Autowerke - Corporate Logo
T#:2302749
Part#: 14-016
Ships on Oct 23, 2026
$ 141.99 USD
Free Shipping
$ 141.99 USD
Free Shipping
CNC machined coolant/water thermostat bypass tube to improve flow on and off the track. Easy plug and play installation and a durable anodized coating make this a simple and reliable temperature control solution.
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DO88 - Corporate Logo
T#:13891855
Part#: OC110
In Stock at Vendor
$ 1,299.99 USD
Free Shipping
$ 1,299.99 USD
Free Shipping
With a 217% bigger core volume, 178% bigger cooling area, and a 110% higher oil volume, this oil cooler compensates on no fronts. Built for the track but just as capable on the road, DO88's upgraded oil cooler for the E90/E92 M3 gives you maximum performance and compromises nowhere.
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Vargas Turbo Technologies - Corporate Logo
T#:7530033
Part#: COOLANTCAPBLK
In Stock
$ 79.99 USD
Free Shipping
$ 79.99 USD
Free Shipping
VTT is proud to offer their billet replacement for the factory plastic Coolant Reservoir cap. This cap does away with the weak plastic cap while adding some pop, and color to your engine bay. This coolant cap retains ALL of the factory provisions by simply allowing you to snap the factory pressure-relief into the new Billet Cap. VTT also designed these caps to complement their N5X Billet Oil caps, N5XBillet Oil filter housing caps, and Billet Power Steering cap, so all 4 will have the same design. These caps are offered in 4 colors – Red, Black, Blue, and Clear anodized Replaces Genuine BMW Reservoir Cap # 17117639020 Note: Fitment includes 99% of all BMW with a coolant Reservoir tank from the E series forward, meaning then fit even the brand New G8X M3/4 with the S58, all B58, etc. If your BMW is an E90 or newer this cap most likely will fit
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Vargas Turbo Technologies - Corporate Logo
T#:52164954
Part#: S65COOLHEATBLK
Ships on Oct 23, 2026
New Item
$ 127.99 USD
Free Shipping
$ 127.99 USD
Free Shipping
Upgrade your BMW M3’s engine bay while simultaneously reinforcing your cooling system with the VTT Billet/Silicone Heater Return Pipe Hose.
Vargas Radiator Hose Kit - Black - BMW E9X M3
2X Entries Into Our F80 M3 Sweepstakes
Vargas Turbo Technologies - Corporate Logo
T#:52164958
Part#: S65RHKBLK
Back Ordered
New Item
$ 314.99 USD
Free Shipping
$ 314.99 USD
Free Shipping
The VTT S65 Radiator Hose Kit is the premier cooling system upgrade for the BMW E9X M3.

Vargas Lower Radiator Hose - Black - BMW E9X M3
2X Entries Into Our F80 M3 Sweepstakes
Vargas Turbo Technologies - Corporate Logo
T#:52164955
Part#: S65COLLOWBLK
Ships on Oct 23, 2026
New Item
$ 179.99 USD
Free Shipping
$ 179.99 USD
Free Shipping
Designed for the S65 V8 engine, the VTT Lower Radiator Hose upgrade addresses the common maintenance headaches associated with aging BMW cooling systems.

Vargas Upper Vent Hose - Black - BMW E9X M3
2X Entries Into Our F80 M3 Sweepstakes
Vargas Turbo Technologies - Corporate Logo
T#:52164960
Part#: S65COUVHBLK
Ships on Oct 23, 2026
New Item
$ 74.99 USD
Free Shipping
$ 74.99 USD
Free Shipping
This VTT kit provides a permanent fix by utilizing heavy-duty silicone and anodized billet aluminum ends.
Vargas Water Pump Vent Hose - Black - BMW E9X M3
2X Entries Into Our F80 M3 Sweepstakes
Vargas Turbo Technologies - Corporate Logo
T#:52164956
Part#: S65COPUBLK
Ships on Oct 23, 2026
New Item
$ 104.99 USD
Free Shipping
$ 104.99 USD
Free Shipping
Prevent a roadside breakdown with the VTT Billet/Silicone S65 Water Pump Vent Hose, the ultimate maintenance upgrade for your BMW E9X M3.

Vargas Coolant Hose Upgrade Kit - Black - BMW E9X M3
2X Entries Into Our F80 M3 Sweepstakes
Vargas Turbo Technologies - Corporate Logo
T#:52164951
Part#: S65COOLFULLBLK
Ships on Oct 23, 2026
New Item
$ 524.99 USD
Free Shipping
$ 524.99 USD
Free Shipping
Upgrade your BMW E9X M3’s engine bay and cooling reliability simultaneously with the Vargas Turbo Technologies S65 Billet/Silicone Full Hose Kit.
Vargas Upper Radiator Hose - Black - BMW E9X M3
2X Entries Into Our F80 M3 Sweepstakes
Vargas Turbo Technologies - Corporate Logo
T#:52164959
Part#: S65COUPRABLK
Ships on Oct 23, 2026
New Item
$ 179.99 USD
Free Shipping
$ 179.99 USD
Free Shipping
The VTT Billet/Silicone Upper Radiator Hose is the only solution on the market that addresses both the hose material and the connector integrity simultaneously.