{"product_id":"mitzone-aluminum-thermostat-assembly-with-housing-for-bmw-e46-e39-e60-direct-fit-includes-thermostat-gasket","title":"MITZONE Aluminium Thermostat Assembly with Housing for BMW E46\/E39\/E60 — Direct-Fit, Includes Thermostat \u0026 Gasket","description":"\u003cp\u003e\u003cstrong\u003eMITZONE's upgraded aluminum thermostat assembly with housing is a complete replacement unit that fits many BMW models and replaces part number 11537509227.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThis all-in-one kit combines a metal thermostat housing, a calibrated thermostat, and a gasket to restore coolant control on compatible BMW engines. Built with an aluminum housing for improved longevity over factory plastic pieces, the assembly is designed as a direct-fit replacement for a wide list of BMW chassis and model years. It’s helpful for routine maintenance or when diagnosing coolant leaks and overheating caused by worn plastic housings or failed thermostats.\u003c\/p\u003e\n\n\u003ch3\u003eWhich BMW models does this thermostat assembly fit?\u003c\/h3\u003e\n\u003cp\u003eThe MITZONE assembly is manufactured to match the original mounting points and coolant passages on many BMWs produced around the late 1990s through mid-2000s. Check exact engine and year compatibility before ordering to ensure correct fitment.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFits E46: 323i (1999–2000), 323Ci (2000), 325Ci\/325i\/325xi\/330Ci\/330i\/330xi (2001–2006 for various models).\u003c\/li\u003e\n  \u003cli\u003eFits E39\/E60 series including 525i and 530i (1999–2005 model years where applicable).\u003c\/li\u003e\n  \u003cli\u003eFits SUVs and roadsters like X3 (2004–2006), X5 (2001–2006), Z3 (1999–2002), Z4 (2003–2005).\u003c\/li\u003e\n  \u003cli\u003eReplaces BMW OEM part number 11537509227 for compatible applications.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow is this MITZONE unit different from the original thermostat housing?\u003c\/h3\u003e\n\u003cp\u003eMITZONE uses an aluminum housing instead of the common factory plastic, which reduces the chance of cracks under heat cycling and extends service life. The package delivers a ready-to-install assembly so you don’t need to transfer components from the old unit.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eAluminum housing resists warping and heat-related failure better than plastic.\u003c\/li\u003e\n  \u003cli\u003eIncludes thermostat and gasket for a full, single-item repair.\u003c\/li\u003e\n  \u003cli\u003ePrepared for direct bolt-on installation with OEM-style mounting points.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat should I expect during installation and maintenance?\u003c\/h3\u003e\n\u003cp\u003eInstallation typically involves draining part of the cooling system, removing the old housing, swapping the assembly, and refilling coolant. Basic mechanical skills and common tools are usually sufficient; torque to manufacturer specs and test for leaks after cycling the engine.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eRequires coolant drain to below the housing level to prevent spillage.\u003c\/li\u003e\n  \u003cli\u003eInspect hoses and clamps while replacing the housing for preventive maintenance.\u003c\/li\u003e\n  \u003cli\u003eBleed the cooling system per vehicle procedure to remove air pockets.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWill this part solve coolant leaks or overheating?\u003c\/h3\u003e\n\u003cp\u003eReplacing a damaged housing and a worn thermostat often remedies leaks and incorrect thermostat operation that can cause overheating. However, diagnose the entire cooling system—hoses, water pump, radiator, and sensors—if problems persist.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFixes leaks originating at the housing flange and mating surfaces when installed correctly.\u003c\/li\u003e\n  \u003cli\u003eRestores thermostat opening temperature if the original unit was sticking or failed.\u003c\/li\u003e\n  \u003cli\u003eIf overheating continues, further system diagnostics are recommended.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho this is for: Drivers and independent mechanics who maintain BMW models from the late 1990s through the mid-2000s and need a durable, single-piece replacement for the thermostat and housing. This kit is suited for owners replacing cracked plastic housings, addressing leaks at the thermostat cover, or completing a preventive cooling-system service with a metal upgrade.\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 replace BMW part number 11537509227?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. This MITZONE assembly is designed as a direct replacement for OEM part 11537509227 for listed BMW models.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Is installation complicated for a DIYer?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Basic mechanical skills and common tools are sufficient; you’ll need to drain coolant and follow vehicle-specific torque and bleeding procedures.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"MITZONE","offers":[{"title":"Default Title","offer_id":55167236931927,"sku":"B09YRBZF19","price":46.25,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1050\/1524\/7191\/files\/mitzone-thermostat-front-housing.jpg?v=1790379477","url":"https:\/\/britishgarage.co.uk\/products\/mitzone-aluminum-thermostat-assembly-with-housing-for-bmw-e46-e39-e60-direct-fit-includes-thermostat-gasket","provider":"British Garage","version":"1.0","type":"link"}