🔧 Murano - Thermostat Replacement

The thermostat regulates engine temperature by controlling coolant flow to the radiator. If it’s stuck open you may get low heat and poor fuel economy; if it’s stuck closed the engine can overheat. This job involves draining coolant, removing the thermostat housing, installing a new thermostat and gasket, then refilling and bleeding the cooling system.

Difficulty Level: Intermediate | Estimated Time: 2-4 hours

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⚠️ Safety & Precautions

• ⚠️ Work on a fully cool engine; hot coolant can cause severe burns.
• ⚠️ Support the Murano with jack stands; never rely on a floor jack alone.
• ⚠️ Keep coolant away from kids/pets; it’s toxic and sweet-smelling.
• ⚠️ Dispose of used coolant properly; don’t pour it on the ground.
• ⚠️ Battery disconnect is recommended if you’ll work near the cooling fans.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks
• Drain pan (2+ gallon)
• Funnel
• Trim clip removal tool
• Flat-blade screwdriver
• Pliers for hose clamps
• 3/8" ratchet
• 3/8" torque wrench (5–60 Nm range)
• Socket set: 8mm, 10mm, 12mm, 14mm
• 3/8" extension set (3" and 6")
• Plastic razor scraper
• Shop rags

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Engine thermostat - Qty: 1
• Thermostat gasket/O-ring (included with thermostat if applicable) - Qty: 1
• Nissan Long Life Antifreeze/Coolant (blue) premix 50/50 - Qty: 2-3 gallons
• Small hose clamp(s) (optional, if originals are weak) - Qty: 1-2

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📋 Before You Begin

• Park on level ground, set the parking brake, and place wheel chocks behind the rear wheels.
• Let the engine cool completely (ideally overnight).
• Open the hood and remove the radiator cap only when cool (it should not hiss).
• If raising the front for access, lift with a floor jack and support with jack stands at the proper lift points.
• Assumption: Procedure shown for the 3.5L V6 thermostat at the lower radiator hose/water inlet housing.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Disconnect the battery (recommended)

• Use a 10mm socket to loosen the negative battery terminal and remove it from the battery post.
• Tuck the cable aside so it can’t spring back to the post.

Step 2: Remove the lower engine splash shield (if equipped)

• Use a trim clip removal tool for plastic clips and a 10mm socket for bolts.
• Set all clips/bolts aside in a small tray.

Step 3: Drain the engine coolant

• Place a drain pan (2+ gallon) under the radiator drain area.
• Slowly remove the radiator cap by hand (cool engine only).
• Use a flat-blade screwdriver to open the radiator drain cock (if accessible) and let coolant drain.
• If the drain cock is hard to access, use pliers for hose clamps to release the lower radiator hose clamp and carefully crack the hose loose to drain into the pan.

Step 4: Create access to the thermostat housing

• Use an 8mm socket or flat-blade screwdriver to loosen the air intake hose clamps as needed.
• Move the intake ducting out of the way enough to reach the lower radiator hose connection at the engine.
• Tip: Take a quick photo before moving hoses.

Step 5: Remove the lower radiator hose from the thermostat housing

• Use pliers for hose clamps to slide the spring clamp back on the hose.
• Twist the hose gently by hand to break it free, then pull it off the housing.
• Catch any remaining coolant with the drain pan and shop rags.

Step 6: Remove the thermostat housing

• Use a 10mm socket with a 3/8" ratchet and extension to remove the thermostat housing bolts.
• Carefully separate the housing; a small amount of coolant will spill.
• Remove the thermostat and gasket/O-ring.

Step 7: Clean the sealing surfaces

• Use a plastic razor scraper to remove old gasket material (if present) from the housing/engine mating surface.
• Wipe clean with shop rags so the surface is dry and smooth.
• Tip: Don’t gouge aluminum surfaces.

Step 8: Install the new thermostat and gasket

• Install the new thermostat in the same orientation as the old one.
• If the thermostat has a small “jiggle valve”/bleed pin, position it at the top (12 o’clock) unless the part’s instructions specify otherwise.
• Install the new gasket/O-ring (dry, unless the part instructions say otherwise).

Step 9: Reinstall the thermostat housing

• Start all housing bolts by hand to avoid cross-threading.
• Tighten evenly using a 10mm socket.
• Final tighten using a 3/8" torque wrench: Torque to 9.8 Nm (87 in-lbs).

Step 10: Reconnect the lower radiator hose

• Push the hose fully onto the housing.
• Use pliers for hose clamps to slide the clamp back into its original position.
• Verify the clamp is centered over the sealing bead on the housing.

Step 11: Reinstall intake ducting and splash shield

• Reposition any intake ducting and tighten clamps with an 8mm socket or flat-blade screwdriver.
• Reinstall the splash shield using a 10mm socket and trim clip removal tool (for clips).

Step 12: Refill and bleed the cooling system

• Insert a funnel at the radiator fill neck.
• Fill with Nissan Long Life Antifreeze/Coolant (blue) premix 50/50 until full.
• Fill the overflow reservoir to the “MAX” line.
• Reconnect the negative battery cable using a 10mm socket.
• Start the engine and set the HVAC to HOT with the fan on low (this helps move coolant through the heater core).
• Let it idle and watch the coolant level; add coolant as it drops.
• When the engine warms up, confirm the upper radiator hose gets hot (thermostat opening) and that cabin heat is steady.
• Shut the engine off, let it cool fully, then top off the radiator and reservoir again.

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✅ After Repair

• Check for leaks around the thermostat housing and lower radiator hose with the engine running and again after a test drive.
• Verify the temperature gauge stays normal and the heater blows hot air.
• Recheck coolant level the next morning (cold engine) and top off the reservoir if needed.
• If it overheats or you hear gurgling behind the dash, shut it down and re-bleed air from the system.

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💰 DIY vs Shop Cost

Shop Cost: $400-$750 (parts + labor)

DIY Cost: $45-$140 (parts only)

You Save: $255-$705 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2-3 hours.

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🎯 Ready to get started?

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