BMW Coolant & Radiator Hoses for BMW 3 Series E46 (1999-2005)

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We offer replacement hoses from several OE brands that we trust, along with performance silicone upgrades for those who want increased wear resistance compared to factory rubber.
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Mechanical Thermostat Conversion - M52TU/M54
10X Entries Into Our F80 M3 Sweepstakes
Turner Motorsport - Corporate Logo
T#:20617634
Part#: 008785LA01T
Ships on Nov 11, 2026
Sale - Save 17% $ 376.99

This product was last offered at the strikethrough price on
06-14-2026

Starting at $ 312.37 USD
Free Shipping on orders $49 and up
Sale - Save 17%
$ 376.99

This product was last offered at the strikethrough price on
06-14-2026

Starting at $ 312.37 USD
Free Shipping on orders $49 and up

Replace the Achilles heel of your factory cooling system with a stout and reliable mechanical thermostat setup.

The factory E46 thermostat housing is a combined unit featuring a plastic housing and a built in thermostat that you cannot replace separately. These plastic all-in-one units are commonly know to crack or fail causing a headache, a trip on the tow truck and possible damage to your engine.

Taking cues from the reliable M50 thermostat setup we designed a an assembly that not only converts your plastic housing into a billet aluminum unit but also swaps out the integrated thermostat for a separate replaceable thermostat. The ability to swap out thermostats separately from the whole housing opens up doors to changing thermostats to different temperature ratings based on your application while also providing lower maintenance costs. No longer do you have to replace the whole housing but just the thermostat itself.

The billet housing is designed to be utilized with E46 M3 upper and lower radiator hoses and also features -16 ORB connections for custom radiator hoses. A major upgrade from the factory and aftermarket plastic units. Our thermostat housing kit can be used by the savvy daily driver or the track hero who wants to ensure the durability of their cooling system.

Key benefits:

Uses M50/S50 mechanical thermostat for increased reliability
Option to use aftermarket colder thermostats if desired
Thermostat can be replaced separately for lower maintenance cost
Barbed hose connections for use with E46 M3 hoses or built in -16 ORB connections for custom radiator hoses
Design:

Machined out of a single piece of billet 6061 aluminum, this thermostat housing will withstand higher prolonged temperatures and abuse for performance applications
Black anodized with engraved Turner logo on the front to match the Turner Motorsports Power Steering Reservoir
Viton gasket for superior sealing performance
For use with E46 M3 radiator hoses 11537830715 and 11537830716
Kit contents:

6061 Billet Aluminum Thermostat Housing
Mechanical Thermostat
Thermostat Housing Gasket
Thermostat Harness
Optional Silicone or Rubber E46 M3 coolant hoses
Product Development:

Our Billet Thermostat Housing upgrade was designed, engineered, tested and quality inspected by our Research and Development team at Turner. Nothing but the highest level of precision and quality through leading-edge product development technology including FARO laser scanning for reverse engineering and quality inspection, SolidWorks 3D CAD modeling, rapid prototyping utilizing our in-house 3D printer and rigorous long term product testing.

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OEM Style Hose Clamps
10X Entries Into Our F80 M3 Sweepstakes
Turner Motorsport - Corporate Logo
T#:338927
Part#: HOSE-CLAMPS
In Stock
Sale - Save 3% $ 3.99

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

Starting at $ 3.87 USD
Free Shipping on orders $49 and up
Sale - Save 3%
$ 3.99

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

Starting at $ 3.87 USD
Free Shipping on orders $49 and up
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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OEM Rein Upper Radiator Hose - E46 M3
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:2306
Part#: 11537830716
In Stock
$ 33.99

This product was last offered at the strikethrough price on
05-06-2026

$ 22.99 USD
Free Shipping on orders $49 and up
$ 22.99 USD
Free Shipping on orders $49 and up

Replace your cracked or leaking radiator hose to prevent further leaks and potentially catastrophic failure. This hose replaces the Upper radiator hose that connects the thermostat housing to the radiator.

This Upper Radiator Hose fits the following BMWs:
2001-2006 E46 3 Series M3, M3 Convertible

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Rein Radiator Hose - Upper - E46
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:379786
Part#: 17127510952
In Stock
$ 25.09

This product was last offered at the strikethrough price on
06-22-2026

$ 24.95 USD
Free Shipping on orders $49 and up
$ 24.95 USD
Free Shipping on orders $49 and up
A common source of cooling system failure

BMW M52 M54 Water Pipe
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:594294
Part#: 11537502525
In Stock
$ 55.99 USD
Free Shipping on orders $49 and up

BMW M52 M54 Water Pipe is an essential replacement part designed to ensure long-term reliability and optimal performance for your BMW's cooling system. Engineered to replace cracked or broken coolant pipes, this high-quality water pipe from Turner Motorsport guarantees a perfect fit and dependable service. Investing in this replacement pipe helps prevent overheating and potential engine damage, maintaining your vehicle's performance and longevity.

  • Reliable replacement: Designed to replace cracked or broken coolant pipes for improved engine cooling.
  • Optimal fitment: Engineered to ensure a perfect fit and seamless installation.
  • Durable construction: Built with high-quality materials to withstand engine temperatures and environmental conditions.
  • Preventative maintenance: Helps avoid overheating and potential engine damage by ensuring a reliable coolant flow.
  • Vehicle compatibility: Specifically designed for BMW M52 and M54 engine models.

Upgrade your BMW’s cooling system with the BMW M52 M54 Water Pipe from Turner Motorsport for enhanced reliability and performance.

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Heater Inlet Pipe
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:594330
Part#: 11531705210
In Stock
$ 42.39 USD
Free Shipping on orders $49 and up
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.
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Rein Radiator Hose - Lower - E46
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:379779
Part#: 11531436408
In Stock
$ 31.99 USD
Free Shipping on orders $49 and up
A common source of cooling system failure
E46 M3 Radiator Hose - Upper And Lower
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:20617632
Part#: 11537830715KT
In Stock
$ 53.98 USD
Free Shipping on orders $49 and up

Both thermostat housing hoses to replace your worn out rubber and brittle plastic connections.

Over the years and with exposure to extremely hot coolant, the coolant hoses in your vehicle can take a beating. Being made of reinforced rubber, these hoses can fail in a number of ways. Splitting at a hose clamp, swelling, cracking, and breaking are just a few of the ways this hose can leave you stranded. Replace it at the first sign of wear to keep your coolant in your engine.

Comes with both upper and lower thermostat hoses: 11537830715 Lower + 11537830716 Upper

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OEM Rein Lower Radiator Hose - E46 M3
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:2674
Part#: 11537830715
In Stock
$ 23.99 USD
Free Shipping on orders $49 and up

Replace your cracked or leaking radiator hose to prevent further leaks and potentially catastrophic failure. This hose replaces the lower radiator hose that connects the radiator to the thermostat housing.

This Lower Radiator Hose fits the following BMWs:
2001-2006 E46 3 Series M3, M3 Convertible

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OEM Rein Expansion Tank Hose - E46 3-Series
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:363453
Part#: 64218376153
In Stock
$ 82.99

This product was last offered at the strikethrough price on
05-06-2026

$ 34.99 USD
Free Shipping on orders $49 and up
$ 34.99 USD
Free Shipping on orders $49 and up
Expansion tank to heater core
BMW Radiator Hose - 11531436408
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:46719183
Part#: CHK0002
In Stock
$ 46.99 USD
Free Shipping on orders $49 and up
Keep your cooling system leak-free and ready for anything with this Rein radiator hose. Over time, heat cycles, pressure, and age take their toll on rubber, leading to soft spots, cracks, or swelling that can quickly turn into a coolant geyser. Rein hoses are built to meet or exceed OEM specs, using premium materials designed to handle extreme temps and high system pressure without breaking a sweat. Each hose features factory-correct fittings, bends, and diameters for a perfect fit—no trimming, stretching, or wrestling required. Whether you’re refreshing your cooling system during a maintenance overhaul or stopping a slow coolant leak before it becomes a major headache, this Rein radiator hose is what you need to get the job done right.
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Water Pipe
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:594365
Part#: 11537502000
In Stock
$ 39.99 USD
Free Shipping on orders $49 and up
Water pipes are essential for proper cooling. If they are cracked, they are going to need to be replaced as soon as possible to avoid overheating your engine. This water pipe runs from the back of the water pump housing to the expansion tank hose. Includes all required seals, needed for the install.
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Heater Inlet Pipe
We Price Match - Give Us A Call or Chat!
Febi - Corporate Logo
T#:594084
Part#: 11531705210
Ships on Sep 16, 2026
$ 47.46 USD
Free Shipping on orders $49 and up
Runs from the front left side of the engine to the heater inlet
Rein Coolant Bleeder Screw CHW1575 - Priced Each
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:591955
Part#: 17111712788
In Stock
$ 4.99 USD
Free Shipping on orders $49 and up
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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Rein Heater Hose - E46 BMW
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:362531
Part#: 64218363198
Ships in 3 Business Days
$ 9.58 USD
Free Shipping on orders $49 and up
Over time, coolant hoses begin to get brittle and are susceptible to cracking and splitting. Replace your cracked or leaking coolant hose to prevent further leaks and potentially catastrophic failure.
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Coolant Hose With Quick Connectors
We Price Match - Give Us A Call or Chat!
Febi - Corporate Logo
T#:17339415
Part#: 11531436410
Special Order: No Guaranteed ETA
$ 28.99 USD
$ 28.99 USD
Over the years and with exposure to extremely hot coolant, the coolant hoses in your vehicle can take a beating. Being made of reinforced rubber, these hoses can fail in a number of ways. Splitting at a hose clamp, swelling, cracking, and breaking are just a few of the ways this hose can leave you stranded. Replace it at the first sign of wear to keep your coolant in your engine.
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BMW Coolant Flange
We Price Match - Give Us A Call or Chat!
Febi - Corporate Logo
T#:17339423
Part#: 17111707817
Special Order: No Guaranteed ETA
$ 47.99 USD
$ 47.99 USD
Water distribution pipe that connects the expansion tank to the radiator
Meyle - Coolant Hose - Lower Right E46
5X Entries Into Our F80 M3 Sweepstakes
Meyle - Corporate Logo
T#:40478120
Part#: 11531436408
Ships on Sep 16, 2026
$ 32.99 USD
Free Shipping on orders $49 and up
Upgrade your BMW’s cooling system with a dependable solution that meets or exceeds OEM quality.

Coolant Flange - Rear/Engine Block
Fits European models only
5X Entries Into Our F80 M3 Sweepstakes
Meyle - Corporate Logo
T#:55533481
Part#: 11531708808
Ships on Sep 16, 2026
New Item
$ 9.99 USD
Free Shipping on orders $49 and up
$ 9.99 USD
Free Shipping on orders $49 and up
This Meyle Original-grade replacement coolant flange is the perfect solution for refreshing your BMW’s cooling plumbing back to factory-fresh operation.
BMW Radiator Hose Kit - 11537830715
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:46719180
Part#: CHK0376R
Ships in 3 Business Days
$ 43.99 USD
Free Shipping on orders $49 and up
Keep your cooling system sealed, strong, and ready for anything with this Rein radiator hose kit—your all-in-one fix for cracked, leaking, or worn factory hoses. Years of heat, pressure, and age can cause rubber to weaken, split, or swell, setting the stage for coolant leaks and potential overheating. Rein hoses are engineered to meet or exceed OEM standards, built from premium, heat-resistant materials that can take on extreme temperatures and system pressures without faltering. Each hose features factory-correct bends, fittings, and diameters for an exact, hassle-free installation—no cutting or forcing required. Whether you’re tackling a full cooling system refresh or chasing down a small coolant leak, this Rein kit provides everything needed to restore confidence and performance under the hood. Why choose this Rein radiator hose kit: Factory-level precision – Direct-fit replacements that deliver OEM-quality reliability. Built to last – Resists cracking, swelling, and chemical damage from daily heat cycling. Confidence restored – Prevents coolant loss, overheating, and on-road breakdowns. All-in-one upgrade – Includes upper and lower hoses for a complete system refresh. If keeping your BMW’s cooling system running tight and trouble-free is the goal, Rein brings the dependable quality and fitment you can count on—engineered to perform just like factory, mile after mile.
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