🔧 Durango - Thermostat Replacement

The thermostat controls when coolant starts flowing through the radiator to keep engine temperature stable. If it sticks closed you can overheat; if it sticks open you may run cool and get poor heat.

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

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⚠️ Safety & Precautions

• ⚠️ Never open the coolant cap on a hot engine—hot coolant can spray and burn.
• ⚠️ Support the SUV securely if you raise it: use jack stands, not just a jack.
• ⚠️ Keep coolant off belts and electrical connectors; wipe spills immediately.
• ⚠️ Coolant is toxic—catch it in a drain pan and dispose of it properly.
• Disconnecting the battery is not required for this job unless you’ll be unplugging multiple connectors near the throttle body.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• Drain pan (at least 10-liter)
• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks
• Trim clip removal tool
• Flat-blade screwdriver
• 8mm socket
• 10mm socket
• 13mm socket
• 1/4" drive ratchet
• 3/8" drive ratchet
• Socket extension set (3" and 6")
• Hose clamp pliers
• Torque wrench (inch-pound)
• Torque wrench (foot-pound)
• Razor scraper or plastic gasket scraper
• Shop towels
• Funnel
• Spill-free funnel kit (specialty)

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Engine thermostat - Qty: 1
• Thermostat seal / O-ring - Qty: 1
• Engine coolant (OAT, 50/50 premix) - Qty: 2-3 gallons
• Hose clamp (worm-gear or OEM-style) - Qty: 1 Only if clamp is weak/damaged

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📋 Before You Begin

• Park on level ground, set the parking brake, and let the engine cool fully (best: overnight).
• Set HVAC to full hot before you start bleeding later (helps push air out of the heater core).
• Have a drain pan ready. You’ll lose coolant when the hose and housing come off.
• Tool tip: A torque wrench tightens bolts to a set spec.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Make it safe and accessible

• Use wheel chocks behind the rear wheels.
• If you need more room underneath, lift the front with a floor jack (rated 3-ton minimum) and support with jack stands (rated 3-ton minimum).
• Put on safety glasses and nitrile gloves.

Step 2: Drain enough coolant

• Place a drain pan (at least 10-liter) under the radiator drain area.
• Slowly loosen the coolant pressure cap (only if fully cool) by hand.
• Open the radiator drain (if accessible) using a flat-blade screwdriver as needed, and drain until the level is below the thermostat housing height.
• If you can’t access the drain easily, you can drain by removing the lower hose later, but expect a bigger spill.

Step 3: Remove the intake ducting (for access)

• Loosen the intake hose clamps using an 8mm socket (some clamps use 8mm heads).
• Release any clips with a trim clip removal tool, then lift the intake tube/air duct out of the way.
• Set hardware aside in a small tray so nothing gets lost.

Step 4: Locate the thermostat housing and hose

• The thermostat sits in a housing at the front of the engine where a large radiator hose meets the engine.
• Put shop towels under the housing area to catch drips.

Step 5: Remove the radiator hose from the housing

• Use hose clamp pliers to compress the spring clamp and slide it back on the hose.
• Twist the hose to break it free, then pull it off the housing (aim it into the drain pan (at least 10-liter)).
• Tip: Don’t pry hard on plastic fittings.

Step 6: Remove the thermostat housing

• Remove the housing bolts using a 10mm socket and a 1/4" drive ratchet (use socket extension set (3" and 6") if needed).
• Pull the housing straight off. More coolant will spill—keep the drain pan (at least 10-liter) under it.
• Remove the thermostat and the old seal/O-ring.

Step 7: Clean the sealing surface

• Use a razor scraper or plastic gasket scraper to clean the mating surface until it’s smooth.
• Wipe clean with shop towels. Do not leave old seal material behind.

Step 8: Install the new thermostat and seal

• Install the new seal/O-ring on the new thermostat (or into the housing, depending on the design).
• Set the thermostat into position the same way the old one came out.
• Reinstall the housing and start bolts by hand first to avoid cross-threading.
• Tighten housing bolts evenly using a torque wrench (inch-pound): Torque to 12 Nm (106 in-lbs).

Step 9: Reinstall the hose and intake ducting

• Push the hose fully onto the housing.
• Position the clamp back in its original spot using hose clamp pliers.
• Reinstall the intake tube/ducting and tighten clamps using an 8mm socket.

Step 10: Refill and bleed the cooling system

• Refill with Engine coolant (OAT, 50/50 premix) using a funnel.
• Install a spill-free funnel kit (specialty) at the fill point to help purge air.
• Start the engine and let it idle. Set HVAC to hot and medium fan.
• As the engine warms up, watch the funnel level. Add coolant as needed.
• When the thermostat opens, you should see flow in the funnel and the upper hose will get hot.
• Once bubbles stop, shut the engine off, let it cool, then top off to the correct level and reinstall the cap.

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✅ After Repair

• Check carefully for leaks around the thermostat housing and hose connection with the engine running.
• Verify the temperature gauge stays normal on a 10–15 minute drive.
• After the engine fully cools, recheck the coolant level and top off if needed.
• If the check engine light comes on or it still overheats, stop driving and recheck for trapped air or a loose clamp.

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💰 DIY vs Shop Cost

Shop Cost: ₹12,000-₹25,000 (parts + labor)

DIY Cost: ₹3,500-₹9,000 (parts only)

You Save: ₹8,500-₹16,000 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?

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