Sierra 18-3681 Volvo Penta Marine Engine Thermostat

The Sierra 18-3681 is a direct-replacement marine engine thermostat engineered for Volvo Penta diesel inboard engines, including the D4, D6, and D12 series. Operating at a rated temperature of 180°F (82°C), this thermostat helps maintain optimal engine operating temperature for reliable, efficient performance on the water.

Sierra designs this thermostat to meet or exceed OEM specifications, providing a dependable, cost-effective alternative to the factory part. It is a direct interchange for Volvo Penta OEM part number 8149182, as well as cross-references 1303061, 1676306, 1544683, and 1661277.

Key Features:

• Temperature rating: 180°F / 82°C
• Direct OEM replacement — interchangeable with Volvo Penta 8149182
• Also cross-references: 1303061, 1676306, 1544683, 1661277
• Designed for Volvo Penta D4, D6, and D12 diesel inboard engines
• Meets or exceeds OEM specifications for fit, form, and function
• Manufactured by Sierra International, a trusted name in marine engine parts

Sierra International has decades of experience producing high-quality marine engine and drive components. The 18-3681 thermostat is built to withstand the demanding conditions of marine environments, ensuring accurate temperature regulation that is critical for long engine life and peak performance.