Thermostat Housing

Replace the thermostat housing assembly on a 2017 Maserati Levante 3.0L V6 Twin Turbo, including coolant drain, housing removal, and system refill with proper bleeding procedure.

Warnings

Tools required

Parts

• Thermostat housing assembly × 1 — Use OEM Maserati part
• Thermostat housing gasket/O-ring kit × 1 — Usually included with housing
• Hose clamps (if corroded) × 4 — 20-32mm stainless steel
• Coolant drain plug seal × 1 — Use OEM specification

Fluids

• Maserati OAT Coolant — 10 qt

Preparation

1. Ensure engine is completely cold to the touch
2. Park vehicle on level surface and engage parking brake
3. Place wheel chocks behind rear wheels
4. Open hood and secure in raised position
5. Remove engine cover by pulling upward on front clips and lifting off mounting grommets
6. Place coolant drain pan under front of vehicle beneath radiator drain location
7. Remove belly pan screws if equipped to access radiator drain plug

Procedure

1. 1

   Drain cooling system
   Slowly remove radiator cap to release any residual pressure. Locate the coolant drain plug at the bottom of the radiator on the driver side. Using appropriate socket, carefully loosen and remove drain plug, allowing coolant to drain completely into catch pan. If vehicle has drain petcock instead of plug, open petcock by turning counterclockwise. Allow at least 15 minutes for complete drainage.
   Torque spec

   Coolant Drain Plug15 Nm (11 lb-ft)

   Drain Petcock7 Nm (5 lb-ft)
2. 2

   Disconnect battery negative terminal
   Using 10mm socket, loosen and disconnect the negative battery terminal to prevent electrical issues while working near sensors. Secure cable away from battery post.
   ℹ️Disconnecting battery will reset radio presets and may require idle relearn procedure after completion.
3. 3

   Remove upper radiator hose and coolant hoses
   Locate the thermostat housing on the front passenger side of the engine. Using hose clamp pliers or flathead screwdriver, loosen the hose clamps on the upper radiator hose where it connects to the thermostat housing. Twist and pull hose off housing outlet. Similarly, disconnect any smaller coolant bypass hoses connected to the housing, noting their positions for reinstallation. Have shop towels ready to catch residual coolant.
   Torque spec

   Coolant Hose Clamps4 Nm (3 lb-ft)
4. 4

   Disconnect electrical connectors and sensors
   Identify the coolant temperature sensor mounted on or near the thermostat housing. Press the release tab and carefully disconnect the electrical connector. If housing has multiple sensors, label each connector for correct reinstallation. Inspect connectors for corrosion or damage.
   ⚠Do not pull on wires themselves; only grip the connector body to avoid damaging terminals.
5. 5

   Remove thermostat housing mounting bolts
   Using appropriate socket (typically 10mm or 12mm), remove the thermostat housing bolts in a criss-cross pattern to prevent warping. The 3.0L V6 typically has 3-4 bolts securing the housing. Keep bolts organized for reinstallation. Carefully pull housing away from engine block, twisting gently if gasket has sealed to surface. Remove old gasket or O-ring completely.
   Torque spec

   Housing Bolts14 Nm (11 lb-ft)
6. 6

   Clean mating surfaces
   Using plastic gasket scraper, carefully remove all traces of old gasket material from both the engine block mating surface and thermostat housing mounting face. Do not use metal scrapers that could damage aluminum surfaces. Clean surfaces with brake cleaner and wipe with clean shop towels. Inspect surfaces for gouges, corrosion, or warping. Ensure no debris falls into coolant passages.
   ⚠Cover open coolant passages with clean shop towels to prevent debris from entering the cooling system.
7. 7

   Prepare new thermostat housing
   Remove new thermostat housing from packaging and verify it matches the old unit. Install new O-rings or gaskets in the proper grooves on the housing. Lightly lubricate O-rings with fresh coolant to aid installation. If thermostat is separate from housing, ensure it is correctly oriented with the spring side facing into the engine block. Verify bleed valve or jiggle pin is at the highest point when installed.
   ℹ️Do not use oil or grease on O-rings as this can degrade rubber and contaminate coolant.
8. 8

   Install new thermostat housing
   Carefully position new thermostat housing onto engine block, aligning all bolt holes and ensuring gasket/O-rings remain properly seated. Start all mounting bolts by hand to ensure proper thread engagement. Once all bolts are started, tighten in a criss-cross pattern to specified torque. Do not overtighten as this can crack the housing or warp mating surfaces.
   Torque spec

   Housing Bolts14 Nm (11 lb-ft)
9. 9

   Reconnect coolant hoses and sensors
   Reconnect all coolant hoses to the thermostat housing in their original positions. Slide hose clamps into position and tighten to specification. Ensure hoses are fully seated on their barbs with no gaps. Reconnect coolant temperature sensor electrical connector(s) until you hear a positive click. Verify all connections are secure.
   Torque spec

   Coolant Hose Clamps4 Nm (3 lb-ft)
10. 10

    Close drain and refill cooling system
    Install new drain plug seal and reinstall radiator drain plug, or close drain petcock, to specified torque. Reconnect battery negative terminal. Using a funnel at the radiator fill neck, slowly pour Maserati OAT coolant into system. Fill until coolant reaches the fill neck. If available, use vacuum fill tool for faster, more complete fill. Start engine with radiator cap off and allow to idle. Add coolant as level drops. Squeeze upper radiator hose several times to help purge air bubbles.
    ⚠Monitor engine temperature gauge closely during bleeding. Do not allow engine to overheat.
    Torque spec

    Coolant Drain Plug15 Nm (11 lb-ft)

    Drain Petcock7 Nm (5 lb-ft)
11. 11

    Bleed cooling system and check for leaks
    With engine running at idle, turn climate control to maximum heat to open heater core passages. Allow engine to reach operating temperature (thermostat opens around 90°C/194°F). Watch for coolant circulation in radiator and feel upper radiator hose to confirm hot coolant flow. Top off coolant as needed. Once at operating temperature, increase engine speed to 2500-3000 RPM for 30 seconds, then return to idle. Repeat 2-3 times to purge remaining air. Carefully inspect thermostat housing and all hose connections for leaks. Shut off engine and install radiator cap once coolant level is stable.
    ⚠️Keep hands and tools clear of cooling fan which may activate at any time once engine reaches temperature.

Reassembly

1. Verify coolant level in reservoir is between MIN and MAX marks when engine is cold
2. Reinstall engine cover by aligning grommets and pressing firmly until clips engage
3. Reinstall belly pan if removed, ensuring all clips and screws are secure
4. Dispose of used coolant properly at approved recycling facility - do not pour down drains

Verification

• Start engine and verify no coolant leaks at thermostat housing or hose connections
• Confirm engine reaches normal operating temperature (middle of gauge) within 5-10 minutes
• Verify cooling fans activate when engine reaches operating temperature
• Check that heater produces hot air when climate control is set to maximum heat
• After first drive cycle (20-30 minutes), recheck coolant level when engine is cold and top off if necessary
• Monitor engine temperature gauge over next several drives to ensure normal operation
• Verify no coolant temperature warning lights or messages appear on instrument cluster

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