Sierra Thermostat Housing 18-3531 for 7.4L 454 V-8 MIE Closed Cooling Engines, 1996-1997
Sierra Thermostat Housing 18-3531 for 7.4L 454 V-8 MIE Closed Cooling Engines, 1996-1997
The 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.
This 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.
Specifications
- Brand: Sierra
- Manufacturer Part Number: 18-3531
- Product Type: Thermostat Housing
- Weight: 1.41 pounds
- Engine Application: 7.4L EFI MIE 454/V-8
- Cooling System: Closed Cooling (Freshwater Cooling)
- Model Years: 1996-1997
- Serial Number Range: F874815 to K999999
- UPC: 808282183189
Fitment
- MerCruiser 7.4L EFI MIE 454/V-8, Closed Cooling (FWC), model years 1996-1997, serial numbers F874815 to K999999
Frequently Asked Questions
What engines does the Sierra 18-3531 thermostat housing fit? 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.
Does the 18-3531 work on standard cooling 7.4L engines? 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.
How much does the 18-3531 thermostat housing weigh? The Sierra 18-3531 thermostat housing weighs 1.41 pounds.
How do I know if my engine's serial number is in range for this housing? 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.
Is the 18-3531 a genuine Sierra part? Yes, 18-3531 is the Sierra manufacturer part number for this thermostat housing, not a generic or unbranded substitute.
What model years does the 18-3531 cover? This housing is specified for 1996-1997 model year MerCruiser 7.4L EFI MIE FWC 454/V-8 engines.
What is included with the 18-3531? The 18-3531 is sold as a standalone thermostat housing; it does not include the thermostat itself unless otherwise noted at purchase.
Why replace a thermostat housing instead of just the thermostat? 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.
Is the UPC for the 18-3531 thermostat housing 808282183189? Yes, the Sierra 18-3531 thermostat housing carries UPC 808282183189.
Can the 18-3531 be used on a 7.4L MIE engine without closed cooling? 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.