How to replace thermostat infiniti G37 G35 370Z Q50 3.7 FAST

Introduction

This tutorial provides a step-by-step guide on how to replace the thermostat in an Infiniti G37, G35, 370Z, or Q50 with a 3.7-liter engine. A faulty thermostat can lead to overheating issues, so replacing it is essential for maintaining your vehicle's performance. Follow these instructions to complete the task efficiently and effectively.

Step 1: Gather Necessary Tools and Materials

Before starting, ensure you have the following tools and materials ready:

• New thermostat
• Thermostat gasket
• Socket set (including a 10mm and 12mm socket)
• Ratchet and extensions
• Torque wrench
• Coolant
• Drain pan
• Pliers
• Screwdrivers
• Funnel
• Shop towels or rags

Tip

Make sure the engine is cool to avoid burns, and work in a well-ventilated area.

Step 2: Drain the Coolant

1. Locate the drain plug on the radiator.
2. Place a drain pan under the radiator.
3. Open the drain plug and allow the coolant to drain completely.

Common Pitfall

Ensure you close the drain plug securely after draining to prevent leaks when refilling.

Step 3: Remove the Engine Cover

1. Use a socket to remove the bolts securing the engine cover.
2. Carefully lift off the engine cover and set it aside.

Step 4: Access the Thermostat

1. Locate the thermostat housing, which is typically near the engine's upper hose.
2. Disconnect the upper radiator hose by loosening the clamp with pliers and pulling it off.

Step 5: Remove the Old Thermostat

1. Unscrew the bolts holding the thermostat housing in place using a socket.
2. Carefully lift the housing to reveal the old thermostat.
3. Remove the old thermostat and gasket from the housing.

Step 6: Install the New Thermostat

1. Place the new thermostat in the housing, ensuring it is oriented correctly.
2. Apply a new gasket to the housing or clean the surface thoroughly if reusing the old gasket.
3. Reattach the thermostat housing and torque the bolts to the manufacturer's specifications.

Step 7: Reconnect the Upper Radiator Hose

1. Position the upper radiator hose back onto the thermostat housing.
2. Secure it with the hose clamp using pliers.

Step 8: Refill the Coolant

1. Use a funnel to refill the radiator with fresh coolant.
2. Ensure the coolant reservoir is also filled to the appropriate level.

Practical Tip

Check your vehicle’s manual for the recommended type of coolant and capacity.

Step 9: Bleed the Cooling System

1. Start the engine and allow it to reach operating temperature.
2. Open the bleed valve (if equipped) to release any trapped air.
3. Monitor the coolant level and add more if needed.

Step 10: Test the Installation

1. After the engine has cooled, check for any leaks around the thermostat housing and hoses.
2. Ensure the engine reaches the proper operating temperature and that the thermostat is functioning correctly.

Conclusion

Replacing the thermostat in your Infiniti G37, G35, 370Z, or Q50 is a straightforward task that can be done with basic tools. By following these steps, you ensure your vehicle operates efficiently and avoid the risk of overheating. After completing the installation, remember to monitor your coolant levels and check for leaks periodically. If you're comfortable with this task, consider other maintenance projects to keep your vehicle in top shape.