Sierra 18-3535 Thermostat 130F, Replaces Mercury 885599004, Fits Mercury/Mariner 200/225/250 HP Outboards

The Sierra 18-3535 is a 130 degree F (54 degree C) thermostat built for Mercury/Mariner outboard engines. It regulates coolant flow through the engine's cooling system, opening at its rated temperature to help the engine reach and hold proper operating temperature. The housing is white with a digital, no-backlight display and push-button/touch control.

This thermostat is a direct replacement for Mercury Marine OEM part 885599004 and is engineered to meet or exceed the original equipment part it replaces. It fits a range of Mercury/Mariner 3.0L DFI DTS and 3.0L EFI outboards spanning the 200, 225, and 250 horsepower lines, including the SeaPro and 250 Long EFI variants, as identified by their serial number breakpoints below. Each unit weighs 0.09 pounds.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3535
• Product Type: Thermostat
• Temperature Rating: 130 degrees F (54 degrees C)
• Replaces (OEM): 885599004
• Color: White
• Display Type: Digital, no backlight
• Control Type: Push-button/touch control
• Weight: 0.09 pounds
• UPC: 808282241216
• Fitment: Mercury/Mariner outboards: 200 3.0L DFI DTS (ALL), 200 3.0L EFI (2003 & Up)(OT750164 & Up), 200 DFI (1997 & Up)(OG386496 & Up), 225 3.0L EFI (1999 & Up)(OG760300 & Up), 225 3.0L EFI SeaPro (2004 & Up)(OT801000 & Up), 225 3.0L DFI DTS (2003 & Up)(OT599000 & Up), 225 DFI (1998 & Up)(OG590000 & Up), 250 3.0L EFI (1999 & Up)(OG760300 & Up), 250 Long 3.0L EFI (OT861319 & Up)

Fitment

• Mercury/Mariner 200 3.0L DFI DTS (ALL)
• Mercury/Mariner 200 3.0L EFI (2003 & Up)(OT750164 & Up)
• Mercury/Mariner 200 DFI (1997 & Up)(OG386496 & Up)
• Mercury/Mariner 225 3.0L EFI (1999 & Up)(OG760300 & Up)
• Mercury/Mariner 225 3.0L EFI SeaPro (2004 & Up)(OT801000 & Up)
• Mercury/Mariner 225 3.0L DFI DTS (2003 & Up)(OT599000 & Up)
• Mercury/Mariner 225 DFI (1998 & Up)(OG590000 & Up)
• Mercury/Mariner 250 3.0L EFI (1999 & Up)(OG760300 & Up)
• Mercury/Mariner 250 Long 3.0L EFI (OT861319 & Up)

Replaces (OEM)

• 885599004

Frequently Asked Questions

What temperature does the Sierra 18-3535 thermostat open at? 130 degrees F (54 degrees C) is the rated opening temperature of the Sierra 18-3535 thermostat, which controls coolant flow in Mercury/Mariner outboard engines.

Which Mercury/Mariner outboards does part number 18-3535 fit? The Sierra 18-3535 fits Mercury/Mariner 200 3.0L DFI DTS (ALL), 200 3.0L EFI (2003 & Up, OT750164 & Up), 200 DFI (1997 & Up, OG386496 & Up), 225 3.0L EFI (1999 & Up), 225 3.0L EFI SeaPro (2004 & Up), 225 3.0L DFI DTS (2003 & Up), 225 DFI (1998 & Up), 250 3.0L EFI (1999 & Up), and 250 Long 3.0L EFI (OT861319 & Up).

Is the 18-3535 a direct replacement for Mercury 885599004? Yes, Sierra 18-3535 directly replaces Mercury Marine OEM part 885599004.

How much does the Sierra 18-3535 thermostat weigh? 0.09 pounds is the weight of the Sierra 18-3535 thermostat.

What color is the Sierra 18-3535 thermostat housing? White is the housing color of the Sierra 18-3535 thermostat.

What is included when I order the 18-3535? One Sierra 18-3535 thermostat is included per unit.

Is the Sierra 18-3535 an OEM or aftermarket part? Sierra 18-3535 is an aftermarket thermostat engineered to meet or exceed the Mercury OEM part 885599004 that it replaces.

Does the 18-3535 have a digital display? Yes, a digital display with no backlight is built into the Sierra 18-3535 thermostat, along with push-button/touch control.

Will the 18-3535 fit both the standard 250 EFI and the 250 Long EFI? Both are covered: the Sierra 18-3535 fits the Mercury/Mariner 250 3.0L EFI (1999 & Up) as well as the 250 Long 3.0L EFI (OT861319 & Up).

What is the UPC for the Sierra 18-3535 thermostat? 808282241216 is the UPC assigned to the Sierra 18-3535 thermostat.