Thermostat

Replace the engine thermostat and housing assembly on a 2017 Maserati Levante 3.0L V6 Twin Turbo to restore proper engine temperature regulation.

Warnings

Tools required

Parts

• Thermostat assembly with housing × 1 — Use OEM specification
• Thermostat housing gasket/O-ring × 1 — Usually included with thermostat
• Coolant temperature sensor O-ring × 1 — Use OEM specification

Fluids

• Maserati OAT Coolant — 2 qt

Preparation

1. Ensure the engine is completely cold (minimum 2 hours after last operation)
2. Park vehicle on level surface and apply parking brake
3. Remove engine cover by pulling upward on front edge to release clips
4. Place coolant drain pan under vehicle beneath radiator drain location
5. Locate the thermostat housing on the front of the engine block near the water pump

Procedure

1. 1

   Drain cooling system
   Open the radiator drain cock at the lower driver's side of the radiator. Allow coolant to drain into the collection pan. If the thermostat is stuck closed, only partial drainage will occur initially. Remove the coolant reservoir cap to improve drainage flow. Collect and properly dispose of old coolant according to local regulations.
2. 2

   Remove air intake components
   Disconnect the air intake ducting from the throttle body by loosening the hose clamp. Remove the intake air box upper section and filter element to gain access to the thermostat housing area. Set aside components in a clean area.
3. 3

   Disconnect coolant hoses from thermostat housing
   Using hose clamp pliers, reposition the hose clamps on both the upper radiator hose and the bypass hose connected to the thermostat housing. Twist and pull the hoses off the housing connections. Be prepared for residual coolant spillage. If hoses are stuck, use a gentle twisting motion while pulling to break the seal.
4. 4

   Remove coolant temperature sensor
   Disconnect the electrical connector from the coolant temperature sensor located on the thermostat housing. Using a 22mm deep socket or wrench, carefully unthread the sensor from the housing. Remove and inspect the sensor O-ring. If reusing the sensor, keep it clean and protected.
5. 5

   Remove thermostat housing bolts
   Locate the thermostat housing mounting bolts (typically 3-4 bolts securing the housing to the engine block). Using a 10mm socket, remove all mounting bolts in a cross pattern. Keep track of bolt locations as lengths may vary. Note the position of any brackets or ground wires attached to the bolts.
   Torque spec

   Thermostat Housing Bolts15 Nm (11 lb-ft)
6. 6

   Remove thermostat housing assembly
   Carefully pull the thermostat housing away from the engine block. The thermostat is integrated into the housing on this engine. Inspect the mating surface on the engine block for damage or excessive corrosion. If the housing is stuck, gently tap with a rubber mallet to break the gasket seal. Do not pry between aluminum surfaces.
7. 7

   Clean mating surfaces
   Thoroughly clean all gasket material from the engine block mating surface using a plastic scraper. Do not use metal scrapers on aluminum surfaces. Wipe clean with a lint-free cloth. Ensure no debris falls into the coolant passages. Clean the thermostat housing bolt holes in the block with compressed air if available.
8. 8

   Prepare new thermostat assembly
   Remove the new thermostat housing from packaging and verify it matches the original. Install the new gasket or O-ring onto the housing, ensuring it seats properly in the groove. Verify the thermostat valve moves freely and is in the closed position. Do not apply silicone sealant unless specifically required by the replacement part instructions.
9. 9

   Install new thermostat housing
   Position the new thermostat housing onto the engine block, aligning the mounting bolt holes. Ensure the gasket remains properly seated. Insert all mounting bolts by hand, starting threads carefully to avoid cross-threading. Thread in any brackets or ground wires in their original positions.
   Torque spec

   Thermostat Housing Bolts15 Nm (11 lb-ft)
10. 10

    Torque thermostat housing bolts
    Using a torque wrench, tighten the thermostat housing bolts in a cross pattern to 15.0 Nm (11.0 lb-ft). Start with finger-tight, then torque in two stages: first to 8 Nm, then final to 15 Nm. This ensures even gasket compression and prevents warping.
    Torque spec

    Thermostat Housing Bolts15 Nm (11 lb-ft)
11. 11

    Install coolant temperature sensor
    Install a new O-ring onto the coolant temperature sensor if provided. Apply a small amount of thread sealant to the sensor threads as specified. Thread the sensor into the thermostat housing by hand until seated, then torque to 20.0 Nm (15.0 lb-ft). Reconnect the electrical connector ensuring it clicks into place.
    Torque spec

    Coolant Temperature Sensor20 Nm (15 lb-ft)
12. 12

    Reconnect coolant hoses
    Push the upper radiator hose and bypass hose firmly onto the thermostat housing connections until fully seated. Reposition the hose clamps to their proper locations approximately 1/4 inch from the hose ends. Ensure clamps are tight and positioned over the bead on the housing nipples.
13. 13

    Refill cooling system
    Close the radiator drain cock. Using Maserati OAT coolant mixed to manufacturer specifications, slowly fill the cooling system through the coolant reservoir. Fill until coolant reaches the MAX mark. If available, use a vacuum fill tool to eliminate air pockets. Squeeze the upper radiator hose several times to help purge air bubbles. Add coolant as level drops.
14. 14

    Bleed cooling system
    With the coolant reservoir cap still open, start the engine and allow it to idle. Monitor coolant level and add as necessary as air bleeds from the system. Allow engine to reach operating temperature (thermostat opens, cooling fans cycle). Watch for leaks around the thermostat housing. Once fans cycle, shut off engine and allow to cool briefly. Recheck coolant level and top off to MAX mark. Install reservoir cap.

Reassembly

1. Reinstall air intake components in reverse order of removal
2. Reinstall engine cover by aligning clips and pressing down firmly until latched
3. Wipe down any coolant spills from engine bay and undercarriage
4. Check for proper coolant level after the first drive cycle and top off if necessary

Verification

• Start engine and verify no coolant leaks from thermostat housing or sensor
• Allow engine to reach full operating temperature and confirm both radiator cooling fans activate
• Verify temperature gauge reads normal operating range (approximately 190-200°F)
• Check for proper heater operation at idle and under load
• Recheck coolant level after first heat cycle when engine is cold; top off if needed
• Clear any diagnostic trouble codes if present and verify no new codes set after test drive

Related trouble codes on this vehicle

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