Many modern cars, trucks, and SUVs rely on a fluid called antifreeze or coolant to keep the engine at optimal temperature. Coolant circulates heat away from the motor and outside of the car. The Engine Coolant Thermostat regulates coolant flow between the engine, where heat begins, and the radiator, where said heat dispels.

Your INFINITI's Engine Coolant Thermostat is a small but strong device that opens and shuts depending on engine temperature. When you first turn your INFINITI on, the Engine Coolant Thermostat stays closed, barring coolant from flowing until the engine heats up to optimal operating temps. Once your engine is sufficiently warm, the Engine Coolant Thermostat opens, allowing antifreeze to circulate, helping prevent engine overheating.

By supporting your engine's ideal temperature your Engine Coolant Thermostat helps reduce engine wear and minimize harmful emissions. Unlike engine oil and brake pads, coolant thermostats don't need regular replacements. Instead, these thermostats only need to be changed if and when they break.

Some signs that your Engine Coolant Thermostat is not working the way it should include: overheating, engine running cool, a breaking cabin air heater, or an illuminated dashboard light, in certain INFINITI models. Additionally, in certain instances, an Engine Coolant Thermostat that needs replacing may cause drastic changes in coolant levels or faster-than-usual coolant or antifreeze deterioration.

Since the signs of a faulty Engine Coolant Thermostat parallel symptoms of separate issues with the cooling system, we suggest getting your INFINITI inspected at an authorized service center. But, if you're certain that a faulty Engine Coolant Thermostat is to blame, replacing it with a reliable OEM part could help get your engine back to its optimal operating temperature.

Normally, replacing an Engine Coolant Thermostat is a job best left to certified INFINITI technicians. But if you are a mechanic, you may be able to do it yourself. Before starting, ensure that you have the right parts and tools for the job: an authentic INFINITI Engine Coolant Thermostat replacement, a sealing compound or gasket, a wire brush, bucket, protective gloves, and a socket wrench.

Whether you decide to DIY your INFINITI Engine Coolant Thermostat replacement or pay a visit to your closest INFINITI technicians, ensure that you always look to the owner's manual as the source of truth for all things related to your vehicle. Additionally, ensure precise fitment and excellent performance by getting an authentic Engine Coolant Thermostat and other parts made by INFINITI for your INFINITI model and year.

This Engine Coolant Thermostat 212306N20A is engineered for INFINITI FX45 2003-2008, INFINITI I30 2000-2001, INFINITI M35 2006-2010, INFINITI M45 2003-2010, INFINITI Q45 2002-2006, or INFINITI QX4 2001-2003. See the What This Fits tab for more details.

Fits FX35, FX45, I30, M45, Q45