Fel-Pro 35489 Engine Coolant Thermostat O-Ring - To Engine Block

Fel-Pro 35489 Thermostat O-Ring Seal

Fel-Pro 35489 is an engine coolant thermostat O-ring made from premium rubber for dependable sealing at the thermostat housing. Built for application-specific fitment, it helps maintain a tight coolant seal on a wide range of Ford, Lincoln, Mercury, Mazda, and Jaguar vehicles.

• Premium rubber construction for coolant sealing performance
• Inside diameter: 48 mm
• Outside diameter: 51.5 mm
• Thickness: 3.5 mm
• Engine coolant thermostat O-ring / O-ring seal
• Fel-Pro application-specific sealing solution

Application Coverage

Compatible with a broad range of vehicles, including Fits 1997-2014 Ford F-150, N/A; Fits 1999-2024 Ford F-250 Super Duty, N/A; Fits 1999-2024 Ford F-350 Super Duty, N/A; Fits 2007-2018 Ford Edge, N/A; and Fits 2007-2016 Lincoln MKZ, N/A. It also fits many other Ford Mustang, Explorer, Taurus, Escape, Expedition, and Lincoln Navigator applications across the listed model years.

This part cross-references MAHLE (e.g., C31302, C32197) for the same application.

Detailed Description

Fel-Pro 35489 is a premium-grade thermostat O-ring used in engine cooling system sealing points where a precise rubber seal is required. The 48 mm inside diameter, 51.5 mm outside diameter, and 3.5 mm thickness support a controlled fit at the thermostat housing or related coolant connection, helping preserve system integrity on vehicles such as the Ford F-150, Ford Explorer, and Lincoln MKZ. Fel-Pro gaskets are known for application-specific materials and vehicle-focused sealing solutions, and this O-ring follows that approach for dependable coolant service.

Common Problems This Seal Can Address

• Coolant seepage at the thermostat housing
• Sealing wear from heat cycling and age
• Loss of coolant seal after thermostat service
• Leak concerns at engine coolant connection points
• Fitment issues when replacing a worn thermostat O-ring

Installation Notes and Tips

Inspect the sealing groove and mating surfaces before installation. Remove old residue, coolant deposits, and any damaged material so the new O-ring seats evenly. Verify the thermostat housing and coolant passage are clean and undamaged, and confirm the dimensions match the original seal before assembly.

Quality Assurance

Fel-Pro focuses on vehicle-specific sealing materials and professional-grade durability for cooling system service. This thermostat O-ring is built to support reliable sealing performance in the listed applications.