{"product_id":"thermostat-housing-for-mercruiser-gm-v6-v8-305-350-454-502-cid-closed-cooling-systems-replaces-807074a1-sierra-18-3531","title":"Sierra Thermostat Housing 18-3531 for 7.4L 454 V-8 MIE Closed Cooling Engines, 1996-1997","description":"\u003cp\u003eThe Sierra 18-3531 is a marine engine thermostat housing built to fit MerCruiser 7.4L EFI MIE 454 cubic inch V-8 engines equipped with closed (freshwater) cooling, model years 1996-1997, within the serial number range F874815 to K999999. The thermostat housing is the component that bolts to the engine and holds the thermostat in place, sealing the coolant circuit so the engine's cooling system can regulate operating temperature correctly. Replacing a cracked, corroded, or leaking thermostat housing with a properly fitted unit like the 18-3531 helps prevent coolant loss and overheating on engines running a closed cooling setup.\u003c\/p\u003e\u003cp\u003eThis housing is sold as a standalone replacement part for the applications listed above. Always confirm your engine's model year and serial number fall within the listed range before ordering, since MerCruiser 7.4L applications changed housing part numbers across different cooling configurations and production runs.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-3531\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Thermostat Housing\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 1.41 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine Application:\u003c\/strong\u003e 7.4L EFI MIE 454\/V-8\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCooling System:\u003c\/strong\u003e Closed Cooling (Freshwater Cooling)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eModel Years:\u003c\/strong\u003e 1996-1997\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSerial Number Range:\u003c\/strong\u003e F874815 to K999999\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282183189\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eMerCruiser 7.4L EFI MIE 454\/V-8, Closed Cooling (FWC), model years 1996-1997, serial numbers F874815 to K999999\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-3531 thermostat housing fit?\u003c\/strong\u003e The 18-3531 fits MerCruiser 7.4L EFI MIE 454 cubic inch V-8 engines with closed (freshwater) cooling, model years 1996-1997, within serial number range F874815 to K999999.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-3531 work on standard cooling 7.4L engines?\u003c\/strong\u003e No, the 18-3531 is designated for closed (freshwater) cooling 7.4L EFI MIE 454\/V-8 engines specifically; a different housing part number applies to standard cooling versions of the 7.4L MIE engine.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-3531 thermostat housing weigh?\u003c\/strong\u003e The Sierra 18-3531 thermostat housing weighs 1.41 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow do I know if my engine's serial number is in range for this housing?\u003c\/strong\u003e The 18-3531 covers MerCruiser 7.4L EFI MIE FWC 454\/V-8 engines with serial numbers between F874815 and K999999; check your engine's serial tag against that range before ordering.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-3531 a genuine Sierra part?\u003c\/strong\u003e Yes, 18-3531 is the Sierra manufacturer part number for this thermostat housing, not a generic or unbranded substitute.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat model years does the 18-3531 cover?\u003c\/strong\u003e This housing is specified for 1996-1997 model year MerCruiser 7.4L EFI MIE FWC 454\/V-8 engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included with the 18-3531?\u003c\/strong\u003e The 18-3531 is sold as a standalone thermostat housing; it does not include the thermostat itself unless otherwise noted at purchase.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy replace a thermostat housing instead of just the thermostat?\u003c\/strong\u003e If the housing itself is cracked, corroded, or no longer sealing properly, replacing just the thermostat will not stop coolant leaks or overheating; the 18-3531 replaces the housing component that seals the coolant circuit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the UPC for the 18-3531 thermostat housing 808282183189?\u003c\/strong\u003e Yes, the Sierra 18-3531 thermostat housing carries UPC 808282183189.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan the 18-3531 be used on a 7.4L MIE engine without closed cooling?\u003c\/strong\u003e No; the 18-3531 is built for the closed (freshwater) cooling configuration of the 7.4L EFI MIE 454\/V-8, so it should not be used on a standard raw-water cooled version of that engine.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988150759643,"sku":"SIE-18-3531","price":18.37,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/18-3531__11789.1737885550.500.750.jpg?v=1785188238","url":"https:\/\/www.goodvibesmarina.com\/products\/thermostat-housing-for-mercruiser-gm-v6-v8-305-350-454-502-cid-closed-cooling-systems-replaces-807074a1-sierra-18-3531","provider":"Good Vibes Marina","version":"1.0","type":"link"}