🔧 Equinox - Thermostat Replacement

The thermostat on your Equinox sits in a housing on the front of the engine and controls coolant flow and engine temperature. You'll remove some intake parts and coolant hoses, swap the thermostat/housing assembly, then refill and bleed the cooling system.

Difficulty Level: Intermediate | Estimated Time: 2-3 hours

---

⚠️ Safety & Precautions

• ⚠️ Only work on the cooling system when the engine is completely cold; hot coolant can cause serious burns.
• ⚠️ Coolant is toxic to people and animals; catch all coolant in a drain pan and dispose of it properly.
• ⚠️ Support the vehicle with jack stands if you raise it; never rely only on a jack.
• ⚠️ Keep tools and parts clear of the drive belt and fans; they can move unexpectedly.
• ⚠️ Disconnect the negative battery cable if you’re worried about accidentally shorting anything or bumping the starter.

---

🔧 Required Tools

You'll need the following tools for this repair:

• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum, pair)
• Wheel chocks
• Safety glasses
• Mechanic gloves
• 3/8" drive ratchet
• 1/4" drive ratchet
• 3/8" drive extension (6")
• 1/4" drive extension (6")
• 8mm socket
• 10mm socket
• 13mm socket
• E8 external Torx socket
• Torx T20 screwdriver
• 1/4" drive inch-pound torque wrench (30–200 in-lbs range)
• 3/8" drive foot-pound torque wrench (10–80 ft-lbs range)
• Flathead screwdriver (small)
• Hose clamp pliers (specialty)
• Needle nose pliers
• Trim clip removal tool
• Drain pan (at least 3 gallons capacity)
• Small funnel
• Shop towels or rags
• Plastic scraper
• Parts cleaning brush

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Thermostat housing assembly (with thermostat and seal) - Qty: 1
• Upper radiator hose O-ring or gasket - Qty: 1 (if separate from housing)
• Coolant outlet pipe O-ring - Qty: 1
• Engine coolant (Dex-Cool, concentrate) - Qty: 2 gallons
• Distilled water - Qty: 2 gallons
• Replacement hose clamps (spring or worm-gear, correct size) - Qty: 2–4
• Throttle body gasket - Qty: 1 (recommended if removed)
• Shop towels - Qty: 1 pack

---

📋 Before You Begin

• Park the Equinox on level ground, set the parking brake, and let the engine cool completely (ideally several hours).
• Turn off all accessories and remove the key from the ignition.
• Open the hood and support it with the prop rod.
• If you prefer extra safety, disconnect the negative battery cable using a 10mm socket.
• Mix coolant 50/50: equal parts Dex-Cool concentrate and distilled water, unless you buy premixed.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Raise the front and drain some coolant

• Place wheel chocks behind the rear wheels.
• Use the floor jack to lift the front of the Equinox at the front crossmember.
• Support the vehicle with jack stands under the front subframe points.
• Place the drain pan under the radiator drain (petcock) on the lower passenger side of the radiator.
• Use a flathead screwdriver to gently open the drain; drain about 1–1.5 gallons of coolant so the level is below the thermostat.
• Close the drain snugly with the flathead screwdriver when done. Do not overtighten plastic drains

Step 2: Remove engine cover and intake duct

• Pull up on the plastic engine cover to pop it off its grommets and set it aside.
• Loosen the hose clamps on the air intake duct at the air filter box and throttle body using an 8mm socket or flathead screwdriver.
• Disconnect any small breather hoses from the intake duct by squeezing their tabs with needle nose pliers.
• Lift out the intake duct and set it aside. Keep track of all hose connections

Step 3: Gain access to the thermostat housing

• The thermostat housing on the 3.6 sits at the front of the engine, near the passenger side, where the large upper radiator hose connects.
• If the throttle body blocks access, disconnect its electrical connector by lifting the tab with a flathead screwdriver.
• Remove the throttle body bolts using a 10mm socket and 1/4" ratchet, then gently move it aside with hoses still attached if possible.
• Throttle body bolt torque on reassembly: 10 Nm (89 in-lbs)

Step 4: Remove hoses from thermostat housing

• Place the drain pan under the thermostat area to catch any remaining coolant.
• Use hose clamp pliers to compress the spring clamps on the upper radiator hose and any smaller hoses attached to the housing; slide the clamps back on the hose.
• Twist the hose ends gently to break them free, then pull them off the thermostat housing. Use a flathead screwdriver carefully if they are stuck, but avoid cutting the hose.
• Let any coolant drain into the pan.

Step 5: Remove thermostat housing assembly

• Locate the bolts holding the thermostat housing to the engine block (usually 3 bolts).
• Use a 10mm socket, extension, and 1/4" ratchet to remove the housing bolts in a crisscross pattern.
• If any bolts are external Torx, use an E8 external Torx socket instead.
• Carefully pull the thermostat housing away from the engine; a little coolant will spill.
• Note the orientation of the old thermostat and housing before removal. Match new part orientation
• Thermostat housing bolt torque on reassembly: 10 Nm (89 in-lbs)

Step 6: Clean the sealing surface

• Use a plastic scraper to gently clean the old gasket material or seal from the engine mating surface.
• Wipe the surface with a clean rag; make sure it is smooth and free of debris.
• Do not use metal scrapers that can gouge the aluminum.
• Ensure no debris falls into the coolant passages; stuff a clean rag in the opening while scraping, then remove it after.

Step 7: Install new thermostat housing assembly

• Verify the new thermostat is correctly installed in the new housing with the seal in place.
• Position the new thermostat housing onto the engine, aligning bolt holes.
• Start all housing bolts by hand to avoid cross-threading.
• Tighten the bolts evenly using a 10mm socket and 1/4" ratchet.
• Use the inch-pound torque wrench with a 10mm socket to torque each housing bolt to 10 Nm (89 in-lbs).

Step 8: Reinstall hoses and clamps

• Inspect the ends of all hoses; if they are cracked or swollen, replace them.
• Install new O-rings or gaskets on any pipe connections as needed.
• Push the hoses fully onto the thermostat housing fittings.
• Use hose clamp pliers to slide the clamps back into position over the hose and fitting.
• Make sure clamps sit on the raised bead of the fitting for a good seal.

Step 9: Reinstall throttle body and intake duct

• If removed, place a new throttle body gasket if required.
• Reinstall the throttle body using a 10mm socket and 1/4" ratchet.
• Torque throttle body bolts to 10 Nm (89 in-lbs) with the inch-pound torque wrench.
• Reconnect the throttle body electrical connector until it clicks.
• Reinstall the intake duct, sliding it onto the air box and throttle body.
• Tighten the intake duct clamps using an 8mm socket or flathead screwdriver.
• Reconnect any small breather hoses.
• Press the engine cover back onto its mounting points until it snaps in.

Step 10: Refill cooling system

• Lower the Equinox off the jack stands using the floor jack and remove the stands.
• Remove the coolant reservoir cap by turning it counterclockwise.
• Using a funnel, slowly fill the reservoir with your 50/50 coolant mix up to the “COLD” mark.
• Squeeze the upper radiator hose by hand to help push air out.
• Top off the coolant as the level drops.

Step 11: Bleed air from the system

• With the reservoir cap still off, start the engine and let it idle.
• Turn the heater to maximum temperature and fan to low to open the heater core.
• Watch the coolant level in the reservoir; add more as it drops.
• As the engine warms up, the thermostat will open and the upper hose will get hot.
• When you see a steady coolant level and no more big air bubbles, install the reservoir cap snugly.
• Let the engine reach normal operating temperature and make sure the cabin heater blows hot air.
• Turn off the engine and let it cool completely, then recheck coolant level and top off to the “COLD” mark if needed.

Step 12: Final checks for leaks

• With the engine warm and running, inspect around the thermostat housing, hose connections, and radiator drain for any leaks.
• Tighten loose clamps using hose clamp pliers or a flathead screwdriver as needed.
• Check under the vehicle for dripping coolant.
• Clean any spilled coolant using shop towels.

---

✅ After Repair

• Start the engine from cold and watch the temperature gauge; it should rise to normal and stay there, not overheat or stay very low.
• Confirm the heater works properly and blows hot air once the engine is warm.
• After your first 15–20 minute drive, park the Equinox, let it cool fully, and recheck the coolant level; top off to the “COLD” mark if needed.
• Over the next few drives, keep an eye out for any warning lights, temperature issues, or coolant smells.

---

💰 DIY vs Shop Cost

Shop Cost: $350-$550 (parts + labor)

DIY Cost: $120-$200 (parts + coolant + supplies)

You Save: $230-$350 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5–2.0 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 above to add everything to your cart.