Why Replace Your Thermostat Assembly?

Over time, thermostat assemblies can fail due to heat cycles, corrosion, or internal wear—especially in high-mileage vehicles.

Common Symptoms of a Bad Thermostat:

• Engine overheating
• Engine running too cold
• Fluctuating temperature gauge
• Poor heater performance
• Coolant leaks

Replacing the thermostat assembly helps restore proper cooling system function and protects your engine.

Product Overview: HiSport Thermostat Assembly

This HiSport thermostat assembly is designed as a direct OEM replacement for a wide range of Infiniti, Nissan, and Suzuki vehicles. Learn how to service the 350Z Thermostat using our guide.

Key Features:

• Complete thermostat assembly (ready to install)
• Direct-fit OEM replacement
• Durable, heat-resistant construction
• Ensures accurate temperature regulation
• Helps prevent overheating and engine damage

【Applicability】The part compatible with INFINITI M35 2006-2009 FX35 2003-2008 G35 2003-2007 M45 2007 QX4 2001-2003 Q45 2002.Compatible with Nissan NV1500 2012-2021 NV2500 2012-2021 NV3500 2012-2021 Frontier 2005-2020 Pathfinder 2001-2015 Xterra 2005-2015 350Z 2003-2007.Compatible with Suzuki Equator 2009-2012.Please moderately check your vehicle year/make/model by the usage of the part finder/compatibility

【Part Number】Replaces 21200-31U1B 2120031U1B.pls check the part components number whether match

Compatible Vehicles

Infiniti Models:

• M35
• FX35
• G35
• M45
• QX4
• Q45

Nissan Models:

• NV1500
• NV2500
• NV3500
• Frontier
• Pathfinder
• Xterra
• 350Z

Suzuki Models:

• Equator

(Always verify compatibility by year, engine, and trim level.)

【Advantage】These parts have the similar functions as OE parts, please use them with confidence

Replaces OEM Part Number

• 21200-31U1B

Designed to meet or exceed OEM specifications for fit, performance, and reliability.

Why Replace the Entire Assembly?

Replacing the full thermostat assembly instead of just the thermostat can:

• Prevent future coolant leaks
• Ensure proper sealing
• Reduce installation time
• Improve long-term reliability

【Note】Please check your part pictures with our pictures, it should be completely same. Or It’s going to no longer suit your car. It’s going to save a while and cost
【Service】 When you have any questions or the items you received with problems, contact us right away

Installation Notes

• Located at the engine coolant outlet
• Requires draining coolant before installation
• Replace seals/gaskets if needed
• Basic tools required
• Professional installation recommended if unsure

Performance Benefits

Replacing your thermostat assembly can:

• Maintain proper engine temperature
• Prevent overheating or overcooling
• Improve heater performance
• Protect engine components from damage

Frequently Asked Questions

What happens if the thermostat fails?

It can cause overheating or prevent the engine from reaching optimal temperature, affecting performance and efficiency.

Should I replace the thermostat housing with the thermostat?

Yes, replacing the full assembly ensures proper sealing and reliability.

Is installation difficult?

It varies by vehicle, but many DIYers can complete the installation with basic tools.