🔧 Thermostat - Replacement

The thermostat controls coolant flow so your engine reaches and holds the correct temperature. On your RAV4, replacing it usually means draining some coolant, removing the thermostat housing, and installing the new thermostat and seal before refilling and bleeding the cooling system.

Difficulty Level: Intermediate | Estimated Time: 1.5-3 hours

---

⚠️ Safety & Precautions

• Let the engine and coolant cool fully before opening the cooling system. Hot coolant can cause severe burns.
• Your RAV4 is a hybrid, so the engine can start by itself in READY mode. Keep the vehicle OFF and out of READY unless a step tells you otherwise.
• Use caution around the serpentine belt area and cooling fan. Keep hands and tools clear.
• Disconnect the 12V battery negative terminal before starting. This helps prevent accidental engine start and electrical faults.
• Wear safety glasses and gloves. Coolant is slippery and harmful if spilled.

---

🔧 Required Tools

You'll need the following tools for this repair:

• Ratchet
• 10mm socket
• 12mm socket
• Torque wrench
• Flat-blade screwdriver
• Drain pan
• Funnel
• Trim clip tool
• Needle-nose pliers
• Floor jack (rated 3-ton minimum)
• Jack stands
• Safety glasses
• Nitrile gloves

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Thermostat - Qty: 1
• Thermostat gasket or O-ring - Qty: 1
• Engine coolant, Super Long Life type - Qty: 1-2 gallons
• Replacement hose clamp - Qty: 1 if needed

---

📋 Before You Begin

• Park on level ground and set the parking brake.
• Make sure the engine is completely cold.
• Turn the vehicle OFF and keep the key fob away from the vehicle.
• Disconnect the 12V negative battery cable before starting.
• Have a drain pan ready before opening the cooling system.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Disconnect power

• Use a 10mm socket to disconnect the negative terminal on the 12V battery.
• Set the cable aside so it cannot touch the terminal.

Step 2: Drain coolant

• Place a drain pan under the radiator.
• Use a flat-blade screwdriver or your fingers to open the radiator drain cock, if equipped.
• Drain enough coolant so the level drops below the thermostat housing.

Step 3: Remove access parts

• Use a 10mm socket and trim clip tool to remove the engine cover and any intake ducting that blocks access.
• If needed, raise the front of the vehicle with a floor jack (rated 3-ton minimum) and support it on jack stands.
• Remove the lower splash shield with a 10mm socket and trim clip tool if it blocks access from below.

Step 4: Remove hoses and housing

• Use needle-nose pliers to release the hose clamp on the thermostat housing hose.
• Twist and pull the hose free. Catch any remaining coolant with the drain pan.
• Use a 10mm socket to remove the thermostat housing bolts.
• Lift the housing off carefully. Do not pry on aluminum surfaces.

Step 5: Replace the thermostat

• Remove the old thermostat and gasket or O-ring.
• Install the new thermostat in the same orientation as the old one.
• Install the new gasket or O-ring.
• Reinstall the housing by hand first, then snug the bolts evenly.
• Torque to 9 Nm (80 in-lbs).

Step 6: Reconnect hose and reassemble

• Push the hose fully onto the housing.
• Use needle-nose pliers to position the clamp in the original spot.
• Reinstall the splash shield, intake ducting, and engine cover with a 10mm socket and trim clip tool.

Step 7: Refill coolant

• Use a funnel to refill with the correct engine coolant.
• Fill the reservoir to the proper line.
• Leave the cap off at first so trapped air can escape.

Step 8: Bleed air from the system

• Reconnect the 12V battery negative terminal with a 10mm socket.
• Start the vehicle and let it reach operating temperature.
• Set the heater to HOT and the fan to low.
• Watch the coolant level and add more as air purges out.
• When bubbling stops and heat is steady, install the cap.
• Top off again after the first full heat cycle.

---

✅ After Repair

• Check for leaks at the housing, hose, and drain cock.
• Verify the engine reaches normal temperature and the cabin heat works.
• Recheck coolant level after a full drive and again after the next cool-down.
• If the check engine light returns, scan for coolant temperature or thermostat codes.

---

💰 DIY vs Shop Cost

Shop Cost: $350-$650 (parts + labor)

DIY Cost: $60-$140 (parts only)

You Save: $290-$510 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5-3 hours.

---

🎯 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.