Home
Cooling
Expansion Tanks

Rein BMW Coolant Expansion Tanks for BMW 5 Series G30 (2017+)

On certain models, namely E36, E46, and E90, the factory BMW expansion tank is prone to either breaking at connection points or blowing apart altogether. If you're starting to feel like your expansion tank is on borrowed time, it's probably time to replace with either a direct OE replacement, or strengthen your cooling setup with an aluminum expansion tank - we offer numerous performance upgrades for your expansion tank. Especially if you're someone who likes to track your BMW, we recommend upgrading your expansion tank to avoid ruining your track day.

Sort By:

OEM Rein Expansion Tank w/ Cap - G30 540iX, G32 640iX, G11 740i ...

affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!

T#:33946948

Part#: 17139846642

In Stock

Sale - Save 5% $ 99.65

This product was last offered at the strikethrough price on
06-29-2026

$ 94.67 USD

Add to Wish List

Qty

Sale - Save 5%

$ 99.65

This product was last offered at the strikethrough price on
06-29-2026

$ 94.67 USD

Add to Wish List

The Expansion Tank is an essential part of your vehicle’s cooling system, designed to accommodate the expansion of coolant as it heats up during engine operation. This high-quality tank helps regulate coolant pressure, preventing overheating and ensuring optimal engine performance. Built to meet or exceed OEM standards, this expansion tank is crafted from durable, heat-resistant materials to provide long-lasting reliability. It offers a direct fit for a wide range of European vehicles, ensuring easy installation.

Prevents Overheating: Manages coolant expansion to maintain consistent engine temperature.
Durable Construction: Made from premium, heat-resistant materials to ensure long-term durability.
OEM Quality Fit: Designed for a precise fit, meeting or exceeding original equipment specifications.
Leak-Proof Design: Provides a secure seal to prevent coolant loss and maintain system efficiency.
Easy Installation: Direct replacement part, compatible with a variety of European vehicle models.

Find the Rein Expansion Tank at Turner Motorsport for top-quality replacement parts and reliable performance.

Show More Show Less

Intercooler Expansion Tank

affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!

T#:584477

Part#: 17137647281

Ships in 3 Business Days

Sale - Save 5% $ 71.99

This product was last offered at the strikethrough price on
06-29-2026

$ 68.39 USD

Add to Wish List

Qty

Sale - Save 5%

$ 71.99

This product was last offered at the strikethrough price on
06-29-2026

$ 68.39 USD

Add to Wish List

Rein Expansion Tank Cap

affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!

T#:384807

Part#: 17117639021

Ships in 1-2 days

Sale - Save 5% $ 16.99

This product was last offered at the strikethrough price on
06-29-2026

$ 16.14 USD

Add to Wish List

Qty

Sale - Save 5%

$ 16.99

This product was last offered at the strikethrough price on
06-29-2026

$ 16.14 USD

Add to Wish List

Cap for plastic expansion tank

BMW Coolant Expansion Tank - 17139485733

affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

T#:45791753

Part#: 17139485733

Ships in 3 Business Days

Sale - Save 23% $ 64.99

This product was last offered at the strikethrough price on
04-28-2026

$ 50.03 USD

Add to Wish List

Qty

Sale - Save 23%

$ 64.99

This product was last offered at the strikethrough price on
04-28-2026

$ 50.03 USD

Add to Wish List

Expansion tanks take constant abuse from high heat and harsh coolant, making them prone to cracking or failure over time. A damaged tank can quickly lead to overheating and serious engine damage, so replacement is critical at the first sign of trouble. Features: Direct fitment for hassle-free installation Precision-molded to OE specs for perfect sensor and hose connections Durable construction stands up to extreme heat and coolant chemicals Factory pressure-tested for reliable performance

Show More Show Less

OEM Rein Coolant Expansion Tank Overflow Hose - BMW G30 530e, G12 740...

For Pre-LCI models only

affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

T#:45757471

Part#: 17125A02485

Ships in 3 Business Days

Sale - Save 5% $ 41.99

This product was last offered at the strikethrough price on
06-29-2026

$ 39.89 USD

Add to Wish List

Qty

Sale - Save 5%

$ 41.99

This product was last offered at the strikethrough price on
06-29-2026

$ 39.89 USD

Add to Wish List

This hose connects the expansion tank to the radiator. If your coolant expansion tank hose is cracked or leaking, replace it early to prevent further coolant loss and eventual overheating.