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Rein CPE0034 - Engine Coolant Reservoir Cap
Product Overview
The Rein Engine Coolant Reservoir Cap, part number CPE0034, is an essential component designed for BMW vehicles. This premium-grade cap is engineered to meet or exceed OEM standards, ensuring your vehicle's coolant system operates efficiently. Crafted from high-quality materials, it resists wear and tear, providing long-lasting performance and reliability. Replacing your old or worn-out coolant reservoir cap with the Rein CPE0034 guarantees a secure fit that prevents leaks, maintaining the integrity of your BMW's cooling system. With straightforward installation, this part is ideal for DIY enthusiasts and professionals alike. Choose Rein CPE0034 for dependable performance and peace of mind every time you service your vehicle.
Cross Reference Numbers
This Rein CPE0034 is equivalent to or replaces the following part numbers: 17 11 7 639 021, 17117639021.
Vehicle Compatibility
- BMW M8 4.4 V8 (2020–2022)
- BMW M8 Gran Coupe 4.4 V8 (2020–2021)
- BMW X7 4.4 V8 (2020–2021)
- BMW X5 4.4 V8 (2020–2021)
- BMW M850i xDrive 4.4 V8 (2020–2021)
- BMW M5 4.4 V8 (2020–2021)
- BMW M2 3.0 L6 (2019–2020)
- BMW M4 3.0 L6 (2019–2020)
- BMW X6 4.4 V8 (2019–2021)
- BMW 750i 4.4 V8 (2010–2019)
This may also fit other applications. Please use the vehicle selector tool to verify fitment.
Why Shop at eEuroparts.com?
- Proven Expertise: Over 25 years of experience with European vehicles means we know your car inside and out.
- Exclusive Kits That Fitâ„¢ - complete repair solutions with no guesswork
- Fitment Confidence: Our accurate cataloging ensures you get the right part the first time.
- Fast, Reliable Shipping: Orders ship quickly from our U.S.-based warehouses.
- Transparent Pricing: Competitive prices with no hidden fees or surprise charges.
- Established Trust: Serving the European auto community since 2000.
Frequently Asked Questions
What does the Rein CPE0034 Engine Coolant Reservoir Cap do?
The Rein Engine Coolant Reservoir Cap is designed to seal the coolant reservoir, ensuring that the coolant system maintains the proper pressure and prevents leaks. This is crucial for the efficient operation of your engine's cooling system, helping to maintain optimal temperature levels.
How do I know if my Engine Coolant Reservoir Cap needs replacement?
Common signs that the coolant reservoir cap may need replacement include:
- Coolant leaks around the reservoir area.
- Overheating engine due to insufficient pressure.
- Check engine light related to coolant system issues.
Can I install the Rein CPE0034 myself?
Yes, the installation of the Rein CPE0034 is straightforward and can be performed by DIY enthusiasts. Always ensure that you follow proper safety precautions when working on your vehicle.
What are the symptoms of a faulty Engine Coolant Reservoir Cap?
Symptoms of a faulty coolant reservoir cap include coolant leaks, engine overheating, and fluctuating temperature readings. If you see DTCs such as P0118 or P0128, it may indicate a failing coolant reservoir cap.
Why should I choose Rein for my Engine Coolant Reservoir Cap needs?
Rein is known for its commitment to quality and reliability. Order Rein CPE0034 today for a factory-correct replacement that restores safety and performance.
Note: All information on this page and in the FAQ is for general reference only. Verify fitment and consult a professional as needed. eEuroparts.com is not responsible for incorrect part selection or installation.
- BrandRein
- ManufacturerRein
- MPNCPE0034
- Part TypeEngine Coolant Reservoir Cap
- OE Part Numbers17 11 7 639 021, 17117639021
- FeaturesApplication Type : ApplicationSpecific
Bullet Point 1 : Manufactured to strict engineering standards/specifications in materials and tolerances.
Bullet Point 2 : Direct fit.
Bullet Point 3 : Meets or exceeds pressure specifications demanded by the OE manufacturer.
Bullet Point 4 : Produced by an original equipment supplier.
Container Type : BG
Country of Origin : DE
Item Height : 2.7500
Item Length : 3.7500
Item Level GTIN : 843266070611
Item Qty : 1
Item Quantity Size : 1
Item Quantity Size UOM : EA
Item UOM : EA
Item Weight : 0.2350
Item Weight Unit UOM : LB
Item Width : 3.5000
Link to Manufacturer Page : www.reinautomotive.com
Product Desc Extended 240 : Rein OE Quality expansion tank caps are designed to be direct replacements for OE caps. Rein caps are designed to match or exceed the OE materials used and are produced to the highest standards to ensure long service life.
Product Desc Invoice 40 : Rein Expansion Tank Cap
Product Desc Long 80 : Rein OE Quality Expansion Tank Cap
Product Desc Short 20 : Expansion Tank Cap
- Fitment
- Fitment TypeVehicle Specific
| Year | Make | Model | Submodel | Notes |
|---|---|---|---|---|
| 2021 | BMW | X5 | M (4.4 V8 GAS) | |
| 2021 | BMW | X5 | M50i (4.4 V8 GAS) | |
| 2020 | BMW | X5 | M (4.4 V8 GAS) | |
| 2020 | BMW | X5 | M Competition (4.4 V8 GAS) | |
| 2020 | BMW | X5 | M50i (4.4 V8 GAS) | |
| 2020 | BMW | X5 | xDrive50i (4.4 V8 GAS) | |
| 2020 | BMW | M5 | Base (4.4 V8 GAS) | |
| 2020 | BMW | M5 | Competition (4.4 V8 GAS) | |
| 2020 | BMW | M5 | Edition 35 Years (4.4 V8 GAS) | |
| 2019 | BMW | X5 | xDrive50i (4.4 V8 GAS) | |
| 2019 | BMW | M5 | Base (4.4 V8 GAS) | |
| 2019 | BMW | M5 | Competition (4.4 V8 GAS) | |
| 2018 | BMW | X5 | M (4.4 V8 GAS) | |
| 2018 | BMW | M3 | Base (3.0 L6 GAS) | |
| 2018 | BMW | M5 | Base (4.4 V8 GAS) | |
| 2017 | BMW | X5 | M (4.4 V8 GAS) | |
| 2017 | BMW | M3 | Base (3.0 L6 GAS) | |
| 2016 | BMW | X5 | M (4.4 V8 GAS) | |
| 2016 | BMW | M3 | Base (3.0 L6 GAS) | |
| 2015 | BMW | X5 | M (4.4 V8 GAS) | |
| 2015 | BMW | M3 | Base (3.0 L6 GAS) | |
| 2015 | BMW | 760Li | Base (6.0 V12 GAS) | |
| 2013 | BMW | X5 | xDrive35i (3.0 L6 GAS) | |
| 2013 | BMW | X5 | M (4.4 V8 GAS) | |
| 2013 | BMW | X5 | xDrive50i (4.4 V8 GAS) | |
| 2013 | BMW | M3 | Base (4.0 V8 GAS) | |
| 2013 | BMW | 760Li | Base (6.0 V12 GAS) | |
| 2013 | BMW | 550i xDrive | Base (4.4 V8 GAS) | |
| 2013 | BMW | 550i | Base (4.4 V8 GAS) | |
| 2012 | BMW | X5 | xDrive35i (3.0 L6 GAS) | |
| 2012 | BMW | X5 | M (4.4 V8 GAS) | |
| 2012 | BMW | X5 | xDrive50i (4.4 V8 GAS) | |
| 2012 | BMW | 740i | Base (3.0 L6 GAS) | Notes: To 3/12, w/2.0 Bar |
| 2012 | BMW | M3 | Base (4.0 V8 GAS) | |
| 2012 | BMW | 535i | Base (3.0 L6 GAS) | Notes: To 3/12, w/2.0 Bar |
| 2012 | BMW | 535i xDrive | Base (3.0 L6 GAS) | Notes: To 3/12, w/2.0 Bar |
| 2012 | BMW | 760Li | Base (6.0 V12 GAS) | |
| 2012 | BMW | 550i xDrive | Base (4.4 V8 GAS) | |
| 2012 | BMW | 550i | Base (4.4 V8 GAS) | |
| 2011 | BMW | X5 | xDrive35i (3.0 L6 GAS) | |
| 2011 | BMW | X5 | M (4.4 V8 GAS) | |
| 2011 | BMW | X5 | xDrive50i (4.4 V8 GAS) | |
| 2011 | BMW | 740i | Base (3.0 L6 GAS) | Notes: w/2.0 Bar |
| 2011 | BMW | M3 | Base (4.0 V8 GAS) | |
| 2011 | BMW | 528i | Base (3.0 L6 GAS) | |
| 2011 | BMW | 535i | Base (3.0 L6 GAS) | Notes: w/2.0 Bar |
| 2011 | BMW | 535i xDrive | Base (3.0 L6 GAS) | Notes: w/2.0 Bar |
| 2011 | BMW | 760Li | Base (6.0 V12 GAS) | |
| 2011 | BMW | 550i xDrive | Base (4.4 V8 GAS) | |
| 2011 | BMW | 550i | Base (4.4 V8 GAS) | |
| 2010 | BMW | X5 | xDrive30i (3.0 L6 GAS) | |
| 2010 | BMW | X5 | M (4.4 V8 GAS) | |
| 2010 | BMW | X5 | xDrive48i (4.8 V8 GAS) | |
| 2010 | BMW | M3 | Base (4.0 V8 GAS) | |
| 2010 | BMW | 528i | Base (3.0 L6 GAS) | |
| 2010 | BMW | 528i xDrive | Base (3.0 L6 GAS) | |
| 2010 | BMW | M6 | Base (5.0 V10 GAS) | |
| 2010 | BMW | M5 | Base (5.0 V10 GAS) | |
| 2010 | BMW | 535i | Base (3.0 L6 GAS) | |
| 2010 | BMW | 535i xDrive | Base (3.0 L6 GAS) | |
| 2010 | BMW | 760Li | Base (6.0 V12 GAS) | |
| 2010 | BMW | 550i | Base (4.8 V8 GAS) | |
| 2009 | BMW | X5 | xDrive30i (3.0 L6 GAS) | |
| 2009 | BMW | X5 | xDrive48i (4.8 V8 GAS) | |
| 2009 | BMW | M3 | Base (4.0 V8 GAS) | |
| 2009 | BMW | 528i | Base (3.0 L6 GAS) | |
| 2009 | BMW | 528i xDrive | Base (3.0 L6 GAS) | |
| 2009 | BMW | M6 | Base (5.0 V10 GAS) | |
| 2009 | BMW | M5 | Base (5.0 V10 GAS) | |
| 2009 | BMW | 535i | Base (3.0 L6 GAS) | |
| 2009 | BMW | 535i xDrive | Base (3.0 L6 GAS) | |
| 2009 | BMW | 550i | Base (4.8 V8 GAS) | |
| 2008 | BMW | X5 | 3.0si (3.0 L6 GAS) | |
| 2008 | BMW | X5 | 4.8i (4.8 V8 GAS) | |
| 2008 | BMW | M3 | Base (4.0 V8 GAS) | |
| 2008 | BMW | 528i | Base (3.0 L6 GAS) | |
| 2008 | BMW | M6 | Base (5.0 V10 GAS) | |
| 2008 | BMW | M5 | Base (5.0 V10 GAS) | |
| 2008 | BMW | 535i | Base (3.0 L6 GAS) | |
| 2008 | BMW | 550i | Base (4.8 V8 GAS) | |
| 2007 | BMW | X5 | 3.0si (3.0 L6 GAS) | |
| 2007 | BMW | X5 | 4.8i (4.8 V8 GAS) | |
| 2007 | BMW | 525i | Base (3.0 L6 GAS) | |
| 2007 | BMW | 530i | Base (3.0 L6 GAS) | |
| 2007 | BMW | M6 | Base (5.0 V10 GAS) | |
| 2007 | BMW | M5 | Base (5.0 V10 GAS) | |
| 2007 | BMW | 550i | Base (4.8 V8 GAS) | |
| 2006 | BMW | 525i | Base (3.0 L6 GAS) | |
| 2006 | BMW | 530i | Base (3.0 L6 GAS) | |
| 2006 | BMW | M6 | Base (5.0 V10 GAS) | |
| 2006 | BMW | M5 | Base (5.0 V10 GAS) | |
| 2006 | BMW | 550i | Base (4.8 V8 GAS) | |
| 2005 | BMW | 525i | Base (2.5 L6 GAS) | |
| 2005 | BMW | 530i | Base (3.0 L6 GAS) | |
| 2005 | BMW | 545i | Base (4.4 V8 GAS) | |
| 2005 | BMW | 645Ci | Base (4.4 V8 GAS) | |
| 2004 | BMW | 525i | Base (2.5 L6 GAS) | |
| 2004 | BMW | 530i | Base (3.0 L6 GAS) | |
| 2004 | BMW | 545i | Base (4.4 V8 GAS) | |
| 2004 | BMW | 645Ci | Base (4.4 V8 GAS) |
Warranty Overview
At eEuroparts, we stand behind the quality of the products we sell. Every part we offer is backed by a warranty designed to give you peace of mind and protect your investment.
Standard Warranty – Most Parts
Coverage: 2 years or 24,000 miles (whichever comes first) from purchase date.
Protection: Defects in materials or workmanship under normal personal use.
Eligibility: Applies only to the original purchaser and the vehicle where the part was first installed.
Exclusions:
Wear-and-tear items (brake pads, filters, bulbs, wipers, etc.)
Commercial, fleet, rideshare, off-road, or racing use
Improper installation, misuse, accidents, or modifications
Not Covered: Labor, shipping, towing, or incidental costs.
Bison Performance Warranty – Our House Brand
Coverage: Limited Lifetime Warranty for as long as you own your vehicle.
Applies To: All products sold under the Bison Performance label.
Premium Protection: Goes beyond our standard warranty — if it’s a Bison product, the 2-year/24k mile limit is replaced with lifetime coverage.
Exclusions: Same as the standard warranty (normal wear, commercial use, improper installation, etc.).
What’s Included: Replacement of the defective product (labor and shipping excluded).
Warranty Claim Requirements
To keep claims fast and fair, we require:
Proof of purchase (invoice or order confirmation).
Photos or videos showing the defective part, order number, date, VIN, and odometer reading.
Diagnostic reports or part returns for non-visible issues may be requested.
Claims must be truthful, properly documented, and reflect normal consumer use.
Buy With Confidence: We back our products because we believe in their quality, with a transparent, customer-first warranty process you can trust. And with Bison Performance products, you’ll enjoy Limited Lifetime protection—an assurance few brands can match.
For full details and exclusions, please see our complete Warranty Terms & Conditions.
This summary is for convenience only. For full warranty coverage details, exclusions, and requirements, see our official Warranty Terms & Conditions. In case of conflict, the full policy governs.
Return Policy Overview
Most parts can be returned within 30 days of delivery if unused, uninstalled, and in original packaging.
To start a return, contact customer support via Chat or Contact Us.
Restocking fee: Up to 20% may apply for certain orders (buyer’s remorse, order errors, or special-order items)
Refunds: Issued to your original payment method within 3–5 business days after inspection
Exchanges: Not automatic — please return and reorder
Replacements: May be approved for incorrect or defective items reported within 7 days
Not returnable:
Used or installed parts
Electrical components
Opened filter kits, gaskets, or contaminated items
Final sale or custom orders
Important Notes:
Return shipping is your responsibility unless we made a verified error
Fitment is the customer’s responsibility (we can assist, but do not guarantee)
Country of origin may vary and is not grounds for return
For complete details, please see our full Return Policy.
This Returns summary is provided for convenience only. All returns, refunds, and exchanges are subject to the complete Returns Policy. In the event of any conflict, the full policy governs.
Fast, Reliable Shipping — Straight to Your Door
We ship most orders the same day when placed before 2 PM CST (Monday–Friday). Our main warehouse is just east of Nashville, TN, and we also ship from multiple locations nationwide to get your order to you as quickly as possible.
We use trusted carriers like UPS, FedEx, and USPS.
Tracking info is emailed to you as soon as your order ships.
Delivery estimates at checkout are based on carrier data, but not guaranteed.
Need help with a shipment?
If your order is missing, damaged, or incorrect, just let us know within 5 days of delivery. We’ll walk you through the quick claim process — including a few photos to help us make things right.
For complete details, please see our full Shipping Policy.
This Shipping summary is provided for convenience only. Delivery times, carrier terms, fees, restrictions, risk of loss, and other details are governed by our complete Shipping Policy. In the event of any conflict, the full policy governs.










