🔧 Fusion - Thermostat Replacement

On your Fusion, the thermostat controls engine coolant flow to help the engine warm up quickly and maintain proper operating temperature. Replacing it usually involves draining some engine coolant, removing the thermostat/housing, installing a new seal, then refilling and bleeding air from the system.

Difficulty Level: Intermediate | Estimated Time: 1.5-3.0 hours

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⚠️ Safety & Precautions

• 🛑 Work on a cold engine only; hot coolant can cause severe burns.
• 🛑 Your Fusion is a hybrid; do not touch any orange high-voltage cables or connectors.
• 🛑 Use jack stands; never rely on a jack alone.
• 🛑 Coolant is toxic; catch it in a drain pan and keep away from pets/kids.

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🔧 Required Tools

You'll need the following tools for this repair:

• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks
• Safety glasses
• Nitrile gloves
• Drain pan (at least 2-gallon)
• 8mm socket
• 10mm socket
• 1/4" drive ratchet
• 3" extension (1/4")
• Torque wrench (inch-pound or low Nm range)
• Hose clamp pliers
• Trim clip remover
• Flat-blade screwdriver
• Funnel
• Shop rags

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Engine coolant thermostat (or thermostat housing assembly) - Qty: 1
• Thermostat seal / O-ring - Qty: 1
• Engine coolant (Motorcraft yellow equivalent, pre-mixed 50/50) - Qty: 1-2 gallons

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📋 Before You Begin

• 🧩 I need one quick detail so the steps match your Fusion exactly: are you replacing the complete thermostat housing assembly or a thermostat insert + O-ring?
• 🧩 Can you tell me what symptom/code you’re fixing (for example P0128, overheating, no cabin heat, coolant leak at housing)?
• Park on level ground, set the parking brake, and let the engine cool completely.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Once you answer the 2 questions above, I’ll give you the exact thermostat location steps and the correct torque specs for your Fusion’s configuration.

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✅ After Repair

• Verify the coolant level after the first full warm-up and again after a short drive.
• Confirm the heater blows hot and the temperature gauge behaves normally.
• Check for leaks around the thermostat/housing and hose connections.

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💰 DIY vs Shop Cost

Shop Cost: $350-$750 (parts + labor)

DIY Cost: $60-$220 (parts only)

You Save: $290-$530 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5-3.0 hours.

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🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.