Fel-Pro 35717 Engine Coolant Thermostat O-Ring

Fel-Pro Engine Coolant Thermostat O-Ring

Fel-Pro 35717 is a premium engine coolant thermostat O-ring built for direct sealing performance in the cooling system. It uses application-specific materials to help maintain a reliable seal where the thermostat housing meets the engine, supporting consistent coolant control on select Ford, Mercury, Pontiac, and Toyota vehicles.

Compatible With 2000-2004 Ford Focus, 1998-2003 Ford Escort, 1998-2000 Ford Contour, 1998-2000 Mercury Mystique, 1999-2002 Mercury Cougar, 2000-2005 Toyota Celica, 2003-2006 Toyota Matrix, 2005-2006 Toyota Corolla, and 2003-2006 Pontiac Vibe. Fel-Pro 35717 is a premium-grade O-ring for cooling system sealing service.

• Premium-grade thermostat O-ring for engine coolant sealing
• Application-specific material selection for the listed vehicle applications
• Supports a tight seal at the thermostat housing interface
• Direct replacement part for cooling system maintenance
• Cross-references K31714 and WP9726 for the same application

Detailed Product Overview

This Fel-Pro engine coolant thermostat O-ring is used to restore the seal between the thermostat and its housing, helping maintain proper coolant flow and reduce leakage at the cooling system connection point. It is a practical service part for cooling repairs on Ford Focus, Ford Escort, Toyota Corolla, Toyota Matrix, and related applications listed in the fitment data. The Fel-Pro 35717 part number is commonly searched by technicians and DIY buyers looking for a thermostat O-ring that matches the vehicle-specific sealing requirement.

Common Problems This Part Can Address

• Coolant seepage around the thermostat housing
• Visible coolant residue near the thermostat seal
• Loss of sealing after thermostat service
• Cooling system leaks traced to the O-ring interface
• Improper sealing from a worn or flattened thermostat O-ring

Installation Notes and Tips

Inspect the thermostat housing and mating surfaces before installation. Clean away old coolant residue, remove any debris, and verify the replacement O-ring seats evenly in the groove before reassembly. Use the correct coolant service procedure for the vehicle and confirm there are no leaks after the system is refilled and bled.

Quality Assurance

Fel-Pro is known for sealing solutions that use application-specific materials and vehicle-focused engineering to support dependable sealing performance. Part number 35717 is a premium thermostat O-ring built for the listed applications and cooling system service requirements.