Sierra 18-3606 Thermostat Kit 130F for Mercury/Mariner V-135 DFI, V-150 DFI, V-175 DFI Outboards

The Sierra 18-3606 Thermostat Kit is a marine engine cooling component built for Mercury/Mariner outboard motors, supplying a 130F thermostat in a white housing to regulate engine operating temperature. Maintaining the correct thermostat rating keeps the engine within its intended temperature range, which protects against overheating and supports consistent cooling system performance in the harsh marine environment. This kit is designed to install into the cooling passage of the outboard powerhead in place of a worn, stuck, or failed thermostat, restoring proper temperature regulation and helping the engine reach and hold its designed operating range.

Sierra manufactures marine parts engineered to meet the demands of high-horsepower engines while standing up to saltwater and freshwater marine conditions, and supplies OEM engine manufacturers and boat builders with parts on a daily basis. The 18-3606 kit fits specific Mercury/Mariner DFI outboard models, so confirming the exact engine designation before ordering ensures the correct thermostat rating and fit for the cooling system.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3606
• Product Type: Thermostat Kit
• Temperature Rating: 130 degrees F
• Color: White
• Weight: 0.1 pounds
• UPC: 808282256784

Fitment

• Mercury/Mariner V-135 DFI (2.5L), 1998 and up
• Mercury/Mariner V-150 DFI (2.5L), 1998 and up
• Mercury/Mariner V-175 DFI (2.5L), 2000 and up

Frequently Asked Questions

What engines does the Sierra 18-3606 thermostat kit fit? The Sierra 18-3606 fits Mercury/Mariner V-135 DFI (2.5L) outboards from 1998 and up, V-150 DFI (2.5L) outboards from 1998 and up, and V-175 DFI (2.5L) outboards from 2000 and up.

What temperature is the 18-3606 thermostat rated for? It opens at 130 degrees F, which is the rating built into the Sierra 18-3606 Thermostat Kit for these Mercury/Mariner DFI outboards.

What color is the thermostat housing? The Sierra 18-3606 kit has a white housing.

How much does the 18-3606 thermostat kit weigh? This Sierra thermostat kit weighs 0.1 pounds.

Is the Sierra 18-3606 an OEM-equivalent part? Sierra engineers the 18-3606 Thermostat Kit to meet or exceed the original equipment part it replaces, and Sierra supplies parts to OEM engine manufacturers and boat builders.

Will this thermostat work on any Mercury outboard? No, the Sierra 18-3606 is designed specifically for the Mercury/Mariner V-135 DFI, V-150 DFI, and V-175 DFI (2.5L) outboards listed in its fitment; it is not a universal-fit thermostat.

Does the 18-3606 kit include a gasket or just the thermostat? The Sierra 18-3606 is sold as a Thermostat Kit rather than a standalone thermostat, packaged as a single unit under UPC 808282256784.

How do I know if my outboard needs a new thermostat? An outboard running hotter than normal, overheating, or showing erratic temperature gauge readings often points to a stuck or failed thermostat, which the Sierra 18-3606 is designed to replace on compatible V-135, V-150, and V-175 DFI engines.

Is the Sierra 18-3606 genuine Sierra or a generic aftermarket part? It is a genuine Sierra-branded part, part number 18-3606, manufactured by Sierra rather than a third-party generic substitute.

What is the difference between the V-135, V-150, and V-175 DFI fitment for this thermostat? All three engines use the same Sierra 18-3606 130F thermostat kit, but each engine has a different model-year starting point in the fitment: V-135 DFI and V-150 DFI from 1998 and up, and V-175 DFI from 2000 and up.