Thermostat: Service and Repair

Thermostat - 3.5L













Removal and Installation

1. Drain the cooling system. For additional information, refer to Cooling System Draining, Filling and Bleeding Service and Repair.

2. Remove the air cleaner and outlet pipe.

3. Disconnect the lower radiator hose from the thermostat housing cover and position it aside.

4. Remove the 2 bolts, thermostat housing cover, O-ring seal and thermostat.
- Clean and inspect the O-ring seal. Install a new seal if necessary.

- To install, tighten to 10 Nm (89 lb-in).


5. NOTICE: Use Motorcraft(R) Specialty Green Engine Coolant or Motorcraft(R) Specialty Orange Engine Coolant. Use the same type of coolant that was originally used to fill the cooling system. Do not mix coolant types. Mixing coolant types degrades the coolant corrosion protection and may damage the engine or cooling system.

NOTICE: Motorcraft(R) Specialty Green Engine Coolant is very sensitive to light. Do NOT allow this product to be exposed to ANY LIGHT for more than a day or two. Extended light exposure causes this product to degrade.

To install, reverse the removal procedure.
- Lubricate the thermostat O-ring seal with clean engine coolant.


6. Fill and bleed the cooling system. For additional information, refer to Cooling System Draining, Filling and Bleeding Service and Repair.