Coolant Thermostat SIERRA 118-3621

Compatible Engines

The SIERRA 118-3621 coolant thermostat is a vital component of your engine's cooling system, designed to maintain optimal operating temperatures. This unit opens at 71 °C (160 °F), ensuring rapid engine warm-up and stable performance under all conditions. Since specific compatible model lists are not provided in the source data, always verify fitment using part number 118-3621 or the original OE number. If you have any doubts about selecting the correct part for your vessel, contact our customer support team for assistance.

Installation and Maintenance

Replacing the thermostat is a key procedure that extends engine life. Regularly checking the thermostat's condition prevents overheating, which is especially critical for boats used intensively. We recommend using only original replacement parts, such as this SIERRA brand product, to ensure full compliance with manufacturer specifications.

• Original SIERRA Quality – guarantees durability and reliable operation.
• Precise Regulation – opens at 71 °C to protect the engine from thermal stress.
• Easy Installation – fits standard thermostat housings without modifications.
• Cooling System Protection – prevents failures in the water pump and cylinder head.