how to troubleshoot overheating issues in my Toyota Highlander XU70 (2020-Present)

Solution

1. Preparation

• Gather tools and parts before starting the repair.
• Disconnect the negative battery terminal to prevent electrical shock.
• Allow the engine to cool down completely.

2. Inspect and Refill Coolant

• Tools Required: Coolant funnel, container for old coolant.
• Remove the radiator cap (when cool) and inspect coolant level.
• If low, refill with the appropriate type of coolant as specified in the owner’s manual.
• Check for leaks around the radiator and hoses.

3. Replace Thermostat (if faulty)

• Tools Required: Socket set, gasket scraper, new thermostat, gasket sealant.
• Drain coolant from the radiator into a container.
• Remove the thermostat housing by unscrewing the bolts.
• Take out the old thermostat and inspect it for damage.
• Install the new thermostat, ensuring it is oriented correctly.
• Reattach the thermostat housing and tighten bolts to manufacturer torque specifications.

4. Inspect and Replace Water Pump (if necessary)

• Tools Required: Socket set, torque wrench, new water pump, gaskets.
• Drain coolant again if necessary.
• Remove the serpentine belt by loosening the tensioner.
• Unscrew and remove the water pump from the engine block.
• Clean the mounting surface and apply gasket sealant if required.
• Install the new water pump and torque the bolts to the manufacturer's specifications.
• Reattach the serpentine belt.

5. Test Cooling Fans

• Tools Required: Multimeter.
• Start the engine and let it warm up.
• Check if the cooling fans engage as the engine reaches operating temperature.
• If they do not operate, consider replacing the fan relay or the fan motor.