Sierra Thermostat Kit 18-3677 for Volvo Penta Engines, 160 Degree F, Replaces 3856961-2

The Sierra 18-3677 Thermostat Kit is a complete marine engine cooling system replacement kit designed for Volvo Penta engines. It is built around a 160 degree F (71 degree C) opening thermostat with an adjustable ring-style controller, and it includes everything needed to complete the job in one purchase: an 18-7170 O-ring, an 18-0398 thermostat gasket, and an 18-3554 component. The thermostat body is finished in bronze, a material choice suited to withstanding the corrosive marine cooling environment.

This kit keeps your engine's cooling system operating within its designed temperature range, which protects against overheating and helps the engine run efficiently. Because it ships as a complete kit rather than a bare thermostat, installers avoid the extra step of separately sourcing a matching gasket and O-ring, reducing the chance of a mismatched seal during replacement. Sierra backs the 18-3677 with a limited warranty.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3677
• Product Type: Thermostat Kit
• Temperature Rating: 160 degrees F / 71 degrees C
• Included Components: 18-7170 O-Ring, 18-0398 Thermostat Gasket, 18-3554
• Color/Finish: Bronze
• Controller Type: Ring, Adjustable
• Weight: 0.1 pounds
• Unit Count: 1
• UPC: 808282146351

Fitment

The Sierra 18-3677 Thermostat Kit is designed for Volvo Penta marine engines. Specific engine models are not specified in available records, so confirm compatibility with your engine's existing thermostat before ordering.

Replaces (OEM)

• VOLVO 3856961-2

Frequently Asked Questions

What temperature does the Sierra 18-3677 thermostat open at? The Sierra 18-3677 Thermostat Kit opens at 160 degrees F (71 degrees C), which regulates coolant flow to keep the engine within its designed operating temperature.

Does the 18-3677 kit include the gasket and O-ring? Yes, the 18-3677 kit is complete and includes an 18-7170 O-ring, an 18-0398 thermostat gasket, and an 18-3554 component, so no separate seals need to be sourced.

What OEM part does the Sierra 18-3677 replace? This kit is a cross-reference match for Volvo OEM part number 3856961-2.

Is the Sierra 18-3677 an OEM or aftermarket part? The 18-3677 is a Sierra aftermarket thermostat kit manufactured as a cross-reference replacement for Volvo OEM part 3856961-2, not a Volvo-branded part.

What engines is the 18-3677 thermostat kit designed for? The Sierra 18-3677 Thermostat Kit is designed for Volvo Penta marine engines; specific engine models are not listed, so match it against your existing thermostat before ordering.

How much does the 18-3677 thermostat kit weigh? The Sierra 18-3677 Thermostat Kit weighs 0.1 pounds.

What material is the 18-3677 thermostat housing? The Sierra 18-3677 Thermostat Kit has a bronze finish, a material well suited to marine cooling system environments.

Is the thermostat in the 18-3677 kit adjustable? Yes, the 18-3677 uses a ring-style adjustable controller.

Does the Sierra 18-3677 come with a warranty? The Sierra 18-3677 Thermostat Kit is backed by Sierra's limited warranty.

How many thermostats are included in the 18-3677 kit? The 18-3677 kit ships as a single-unit count, containing one thermostat along with its matching O-ring and gasket.

What is the UPC for the Sierra 18-3677 Thermostat Kit? The UPC for the Sierra 18-3677 Thermostat Kit is 808282146351.