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OEM Behr Coolant Expansion Tank Cap 2.0 Bar - E36 E46 E34 E39 E32 E38...

T#:2766

Part#: 17111742231

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$ 20.99

This product was last offered at the strikethrough price on
09-10-2026

$ 19.99 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.

Hailing from Stuttgart, Mahle-Behr specializes in automotive cooling systems. From air conditioning to engine cooling M-B has you covered with OE-quality replacement parts.

This item fits the following BMWs:
1990-1991 E30 BMW 318i 318is 318ic
1992-1998 E36 BMW 318i 318is 318ic 323is 323ic 325i 325is 325ic 328i 328is M3
1999-2005 E46 BMW 323i 323ci 325i 325ci 325xi 328i 328ci 330i 330ci 330xi M3
1989-1995 E34 BMW 530i 535i 540i M5
1991-1995 E34 BMW 525i
1997-2003 E39 BMW 525i 528i 530i 540i M5
1989-1994 E32 BMW 735i 735il 740i 740il 750il
1995-2001 E38 BMW 740i 740il 750il
2002-2008 E65 BMW 745i 745li 750i 750li 760i 760li
1990-1998 E31 BMW 840i 840ci 850i 850ci 850csi
2004-2011 E83 BMW X3 2.5i X3 3.0i X3 3.0si
2000-2006 E53 BMW X5 30.0i X5 4.4i X5 4.6is X5 4.8is
1996-2002 Z3 BMW Z3 1.9 Z3 2.3 Z3 2.5i Z3 2.8 Z3 3.0i M Coupe M Roadster
2003-2008 E85 BMW Z4 2.5i Z4 3.0i Z4 3.0si M Roadster M Coupe
2000-2003 E52 BMW Z8 Z8 Alpina
2007+ E90 BMW 335i & 335xi

Coolant Expansion Tank - E85 E86 Z4

T#:7457

Part#: 17117573751

Ships in 3 Business Days

$ 289.99

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 189.99 USD

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This high quality Genuine BMW brand expansion tank is used on M54 and N52 engines, and is a common failure item on all E85 Z4's. Be leary of competitors selling this part for less -- is it a Genuine BMW? Probably not.

If you are overhauling your coolant system, now is the time to consider preventative replacing this expansion tank. These are known to go bad, causing a leak which can leave you stranded. We have found that the expansion tanks should be replaced based on age as well as condition. Expansion tanks seem to have a lifespan of less than six years before they show signs of fatigue and wear. Pre-emptively replacing the expansion tank as part of an overall maintenance plan can prevent you from getting stranded from a sudden failure later on.

When doing any sort of repair or maintenance there is no replacement for genuine factory parts. Turner Motorsport carries the Genuine BMW brand with pride and has the parts you need to complete your next project with confidence.

This item fits the following BMWs:
2003-2008 E85 BMW Z4 2.5i Z4 3.0i Z4 3.0si

Coolant Expansion Tank

2X Entries Into Our F80 M3 Sweepstakes

T#:363421

Part#: 17117573751

Ships in 2 Business Days

$ 64.99 USD

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MMX 90mm Billet Coolant Expansion Tank Cap | BMW

T#:29002094

Part#: MMR03-1502

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$ 127.99 USD

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The MMX Performance 90mm billet coolant expansion cap for BMWs has been designed from the ground up in the UK, from a solid piece of billet aluminum. Each cap was designed to directly replace the OE cap, not merely stuck in place. Fitment is for models with the matching OE (17 11 7 639 021) part number.

ECS Tuning Aluminum Coolant Bleeder Screw

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T#:363070

Part#: 003530ECS01A

In Stock

Sale - Save 25% $ 35.99

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

$ 26.99 USD

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Sale - Save 25%

$ 35.99

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

$ 26.99 USD

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Replace the flimsy plastic bleeder screw used in the coolant expansion tank or in one of the cooling system hoses with this high quality, durable, aluminum bleeder screw. The stock plastic screw can deform over time due to heat or even regular use. We have even seen the head of the screw snap off, leaving the threaded body stuck in the expansion tank. This aluminum screw will help to prevent sudden failure of the bleeder screw, which can result in immediate overheating of the car.

ECS Tuning's Aluminum Coolant Bleeder Screw replaces Genuine BMW Part Number 17111712788

Bremmen Coolant Bleeder Screw - BMW E30 E36 E38 E39 E46 E83 E90 Z4 ...

10X Entries Into Our F80 M3 Sweepstakes

T#:640140

Part#: 17111712788

Ships on Dec 10, 2026

Sale - Save 39% $ 3.99

This product was last offered at the strikethrough price on
09-02-2026

$ 2.44 USD

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Sale - Save 39%

$ 3.99

This product was last offered at the strikethrough price on
09-02-2026

$ 2.44 USD

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VTT Billet Coolant Reservoir Cap - Anodized Blue - Most BMWs 2006+ (E...

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T#:7530036

Part#: COOLANTCAPBLUE

In Stock

$ 79.99 USD

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$ 79.99 USD

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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

VTT Billet Coolant Reservoir Cap - Anodized Red - Most BMWs 2006+ (E/...

2X Entries Into Our F80 M3 Sweepstakes

T#:7530034

Part#: COOLANTCAPRED

Ships in 2 Business Days

$ 79.99 USD

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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

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

T#:7530035

Part#: COOLANTCAPRAW

Back Ordered

$ 78.99 USD

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$ 78.99 USD

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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

Water Connector - Expansion Tank To Trans Oil Cooler - E83 Z4 ...

2X Entries Into Our F80 M3 Sweepstakes

T#:50031879

Part#: 17112248409

Ships in 2 Business Days

$ 40.99 USD

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$ 40.99 USD

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Plastic cooling system components degrade and become brittle with age and heat exposure. This particular part is especially prone to damage during expansion tank removal. Always inspect it whenever the expansion tank is removed and replace it if any cracking or wear is found.

VTT Billet Coolant Reservoir Cap - Anodized Black - Most BMWs 2006+ (...

2X Entries Into Our F80 M3 Sweepstakes

T#:7530033

Part#: COOLANTCAPBLK

In Stock

$ 79.99 USD

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Qty

$ 79.99 USD

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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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Showing 11 results for "coolant expansion tank"

OEM Behr Coolant Expansion Tank Cap 2.0 Bar - E36 E46 E34 E39 E32 E38...

Coolant Expansion Tank - E85 E86 Z4

Coolant Expansion Tank

MMX 90mm Billet Coolant Expansion Tank Cap | BMW

ECS Tuning Aluminum Coolant Bleeder Screw

Bremmen Coolant Bleeder Screw - BMW E30 E36 E38 E39 E46 E83 E90 Z4 ...

VTT Billet Coolant Reservoir Cap - Anodized Blue - Most BMWs 2006+ (E...

VTT Billet Coolant Reservoir Cap - Anodized Red - Most BMWs 2006+ (E/...

VTT Billet Coolant Reservoir Cap - Anodized Clear - Most BMWs 2006+ (...

Water Connector - Expansion Tank To Trans Oil Cooler - E83 Z4 ...

VTT Billet Coolant Reservoir Cap - Anodized Black - Most BMWs 2006+ (...

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