Parts for your 2020 Nissan Pathfinder-Thermostat

2020 Nissan Pathfinder Thermostat — Purpose, Replacement and Maintenance

Based on technical sources like the Nissan Pathfinder (R52, MY2020) Factory Service Manual – Cooling System (CO) section – and the Nissan Electronic Parts Catalogue for the VQ35DE 3.5‑litre V6, this model is equipped with a wax‑type engine coolant thermostat. It’s a standard, serviceable component in the cooling system, designed to manage warm‑up and operating temperature. So yes, a thermostat is fitted and very much relevant to the 2020 Pathfinder.

The thermostat regulates coolant flow between the engine and radiator. When the engine is cold it stays closed to help the V6 warm up quickly. As coolant reaches its specified opening temperature (typically around the high‑70s °C per Nissan specs), the valve opens and allows flow through the radiator to hold a stable operating temperature. This keeps fuel economy, heater performance, and emissions in check, while protecting the engine from overheating under load — whether that’s school runs or towing the boat.

For owners, the thermostat is usually a “replace on condition” item rather than scheduled maintenance. Tell‑tale signs of trouble include slow warm‑up, fluctuating temp gauge, poor heater output, a sudden overheat, or a diagnostic code like P0128. If there’s any doubt, inspection and testing per the FSM is the right move.

When replacement is needed on a 2020 Pathfinder, best practice is to use a quality OEM‑spec thermostat with a new seal/O‑ring. The unit is housed near the front of the engine by the lower radiator hose connection. A proper job also means fresh coolant to Nissan specification (correct long‑life premix), new clamps if needed, and bleeding the system to purge air. Always follow torque values and procedures in the factory manual, and check for leaks once it’s heat‑cycled.

To keep the cooling system healthy in Aussie and Kiwi conditions, pair thermostat care with timely coolant changes to the correct spec, inspect hoses and the water pump area for crusting or seepage, and make sure the radiator fans and cap are doing their bit. Look after the cooling system and the Pathfinder’s V6 will stay happy on long hauls and hot days alike.

• Watch for symptoms: erratic temp gauge, heater issues, P0128, or overheating.
• Use OEM‑spec parts and correct coolant, bleed air thoroughly after service.
• Follow the Nissan FSM for procedures and torque settings.

Popular Questions

Where is the thermostat on a 2020 Nissan Pathfinder?

It’s mounted in the thermostat housing at the front of the engine, typically where the lower radiator hose meets the engine. Access is under the bonnet, removal requires draining some coolant and disconnecting the hose and housing before swapping the unit and seal.

What are the signs the thermostat needs replacing?

Common giveaways include the temp gauge taking ages to reach normal, fluctuating temperature, weak cabin heat, or a sudden overheat. The engine computer may log P0128 (coolant temp below thermostat regulating temperature). Any of these warrant testing and, if confirmed, replacement.

Do you need to bleed the cooling system after changing the thermostat?

Yes. Air gets trapped whenever the system is opened. Bleeding per the Nissan service procedure — using the bleed points, correct fill rate, and warm‑up cycles — prevents hot spots and avoids false overheating. Top up once cooled and recheck for leaks.