Thermostat for Volvo Penta Sterndrive 18-3557 Replaces 21148403 (143° F / 62° C)

Thermostat for Volvo Penta Sterndrive

This thermostat, part number 18-3557, replaces OEM 21148403 and regulates engine coolant temperature for Volvo Penta sterndrive engines, opening at 143°F (62°C) to maintain optimal operating conditions.

Overview

This thermostat is a direct replacement for Volvo Penta sterndrive engines, ensuring the engine reaches and maintains its ideal temperature. The thermostat, which replaces 21148403, opens at 143°F (62°C) to allow coolant flow when the engine warms up. It is built to OE specifications for reliable performance in marine environments.

Built For Performance

• Precision temperature rating of 143°F (62°C) for accurate regulation
• Constructed from corrosion-resistant materials for saltwater use
• Direct replacement for Volvo Penta sterndrive systems
• Includes a wax-pellet element for consistent response
• Meets OEM specifications for a perfect fit

On-The-Job Use

• Replacing a stuck-open or stuck-closed thermostat on a sterndrive engine
• Maintaining proper engine temperature during long cruises
• Restoring cooling system efficiency after overheating
• Installing during routine winterization or summerization

Specs At A Glance

Good To Know

Q: Will this thermostat fit my Volvo Penta 5.0 GXi sterndrive? A: This thermostat is designed for Volvo Penta sterndrive engines, but always verify your engine's specific part number for compatibility.

Q: What is the correct installation torque? A: Refer to your service manual; typical torque is around 15 ft-lbs, but confirm with your engine's specifications.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.