Rein BMW Cooling System Parts & Accessories for BMW 7 Series E65 (2002-2008)

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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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Rein - Corporate Logo
T#:362446
Part#: 11531710048
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$ 4.07 USD
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Seals the rear of the water transfer pipe to the block
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T#:340541
Part#: 17111742231
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$ 17.99 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.
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T#:592006
Part#: 17127541146
In Stock at Vendor
$ 36.99 USD
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$ 36.99 USD
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Replace your leaking hose

Coolant Hose
For vehicles with production date from 09/2003
Rein - Corporate Logo
T#:379683
Part#: 17127568246
Ships in 3 Business Days
$ 37.99 USD
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$ 37.99 USD
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This is the return hose that attaches from the water pump to the radiator

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T#:591999
Part#: 17127534527
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$ 30.99 USD
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$ 30.99 USD
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Connects the radiator to the expansion tank
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T#:379749
Part#: 17127535742
Ships in 3 Business Days
$ 89.99 USD
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A common source of cooling system failure

Rein - Corporate Logo
T#:379672
Part#: 17127508013
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$ 60.99 USD
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A commonly leaking hose
Rein - Corporate Logo
T#:379713
Part#: 17127540666
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$ 80.99 USD
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Connects to the radiator

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T#:593077
Part#: 17137647713
Ships in 3 Business Days
$ 99.99 USD
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Replace your cracked or faded tank

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T#:375746
Part#: 17127508011
In Stock at Vendor
$ 75.99 USD
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This hose runs from the lower radiator port on the passenger side of the radiator to the water pump on the engine. Rubber hoses can crack over time, leading to coolant loss. Replace your hose with this OEM Rein hose to eliminate leaks and prevent overheating.
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T#:46719179
Part#: CHK0009P
Ships in 3 Business Days
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$ 67.99 USD
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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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Rein - Corporate Logo
T#:45791754
Part#: 17127508011R
Ships in 3 Business Days
$ 35.99 USD
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This hose runs from the lower radiator port on the passenger side of the radiator to the water pump on the engine. Rubber hoses can crack over time, leading to coolant loss. Replace your hose with this OEM Rein hose to eliminate leaks and prevent overheating.
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Rein - Corporate Logo
T#:386411
Part#: 11511439976
Back Ordered
$ 14.99

This product was last offered at the strikethrough price on
08-12-2026

$ 13.99 USD
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This is the coolant return pipe on the back of the water pump on the N62 and N73 engines used in the E53 X5, E60 545/550, E63 645/650, E65 745/750, E70 X5, and F02 750. This pipe connects the water pump to the valley pan and it's a compression fitting (no o-rings). Whenever the water pump or valley pan are replaced this tube should also be replaced. This is one area where you don't want to go back and re-do your work because of a leaking fitting! In German, Rein means Pure. In the automotive industry the Rein name has quickly come to represent quality. With fitments for some of the worldaEURtms finest automobiles including BMW and Mini and guaranteed OE quality, Rein is a name you can trust.
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Rein - Corporate Logo
T#:375750
Part#: 17127508015
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Attaches from the bottom fitting on the expansion tank to the supply hose. 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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OEM Rein Coolant Supply Hose - E65 E66
For vehicles with production date up to 09/2003
Rein - Corporate Logo
T#:375745
Part#: 17127508010
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$ 134.99 USD
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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.

Coolant Hose
For vehicles with production date up to 09/2003
Rein - Corporate Logo
T#:379702
Part#: 17127508014
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$ 25.99 USD
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This is the return hose that attaches from the water pump to the radiator

Rein - Corporate Logo
T#:14122755
Part#: 17117514402
Back Ordered
$ 8.99

This product was last offered at the strikethrough price on
08-12-2026

$ 8.24 USD
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Mounts to top of radiator bracket, 2 per vehicle.