{"product_id":"x4xz-coolant-overflow-reservoir-with-sensor-for-2012-2019-bmw-120i-520i-complete-tank-cap-included","title":"X4XZ Coolant Overflow Reservoir with Sensor for 2012–2019 BMW 120i–520i | Complete Tank, Cap Included","description":"\u003cp\u003e\u003cstrong\u003eReplacement coolant overflow reservoir with integrated sensor designed to restore proper coolant level monitoring and expansion capacity on select 2012–2019 BMW 120i through 520i models.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWhen an aging or cracked surge tank causes coolant loss, dashboard warnings, or cooling-system imbalance, fitment of a correctly matched reservoir brings back reliable coolant expansion capacity and sensor feedback. The X4XZ 603-880 reservoir is molded and tested to match the specified BMW applications and replaces OE numbers 17137642158 and 17137609469. It ships as a complete tank with cap and sensor-ready connections so you can restore coolant containment and level detection without guessing on compatibility.\u003c\/p\u003e\n\n\u003ch3\u003eWhich BMW models will this reservoir fit?\u003c\/h3\u003e\n\u003cp\u003eThis tank is engineered for a range of BMW 2-, 3-, 4- and 5-series cars with 2.0L four-cylinder engines produced between 2012 and 2019. Confirm your VIN and engine code against the listed applications before ordering to ensure a direct fit.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eCompatible models include: 120i (F20), 220i\/228i (F22\/F23), 320i\/320i xDrive\/328i (F30\/F31), 420i\/428i variants (F32\/F33\/F36), and 520i (F10\/F18 similar years).\u003c\/li\u003e\n  \u003cli\u003eReplaces OE numbers: 17137642158 and 17137609469.\u003c\/li\u003e\n  \u003cli\u003eFits 2.0L L4 engines from model years 2012–2019 where listed.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow does this reservoir help my cooling system perform?\u003c\/h3\u003e\n\u003cp\u003eThe reservoir provides a dedicated expansion space for coolant as temperatures change, preventing air entry and maintaining appropriate radiator pressure cycles. Its sensor-ready design restores accurate level monitoring so warning lights and ECU inputs behave correctly.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eContains expansion and contraction of coolant during heat cycles.\u003c\/li\u003e\n  \u003cli\u003ePrevents overflow and coolant loss from a failing tank.\u003c\/li\u003e\n  \u003cli\u003eSupports level sensor function to keep dashboard indicators accurate.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat are the build quality and included parts?\u003c\/h3\u003e\n\u003cp\u003eThis replacement reservoir is made from durable automotive-grade plastic and is produced to meet fitment and durability expectations for the specified BMW models. The package includes a complete coolant reservoir; mounting hardware and cap are included as fitted to the tank, but no printed manual is provided.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eDurable molded plastic construction designed for long service life.\u003c\/li\u003e\n  \u003cli\u003eFactory-style connections for hoses and level sensor port.\u003c\/li\u003e\n  \u003cli\u003ePackage includes 1 coolant reservoir; easy to install for technicians and DIYers.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow do I install it and what after-sales support is available?\u003c\/h3\u003e\n\u003cp\u003eInstallation is straightforward for anyone familiar with basic cooling-system service: drain coolant to safe level, disconnect hoses and electrical connector, remove old tank, install new reservoir and refill with correct coolant. X4XZ offers customer support and a one-year product service if you encounter fitment or quality issues.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eSimple swap procedure for competent DIY mechanics or professional shops.\u003c\/li\u003e\n  \u003cli\u003eAlways refill with manufacturer-recommended coolant and bleed air per BMW procedure.\u003c\/li\u003e\n  \u003cli\u003eX4XZ provides 24-hour customer service and a one-year product warranty.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: drivers and mechanics who own compatible BMW 120i, 220i, 228i, 320i, 328i, 420i, 428i or 520i models from 2012–2019 and need a direct-fit replacement for a leaking, cracked, or sensor-failing coolant reservoir. Choose this tank when you want an OE-replacement part number match (603-880 \/ 17137642158 \/ 17137609469) with durable construction and responsive after-sales support to return cooling-system function quickly and reliably.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Does this reservoir include the cap and sensor?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: The tank includes the cap and is sensor-ready; check that your vehicle's sensor connector matches before installation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Will this fit my 2015 320i xDrive?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes — the 603-880 reservoir lists compatibility with 2013–2018 320i xDrive L4 2.0L models.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"X4XZ","offers":[{"title":"Default Title","offer_id":55168985235799,"sku":"B0F5Q54S6H","price":74.97,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1050\/1524\/7191\/files\/x4xz-coolant-reservoir-front-view_11a6dda2-e134-4ecd-ac04-e821ceb92c31.jpg?v=1790416249","url":"https:\/\/britishgarage.co.uk\/products\/x4xz-coolant-overflow-reservoir-with-sensor-for-2012-2019-bmw-120i-520i-complete-tank-cap-included","provider":"British Garage","version":"1.0","type":"link"}