Details

• Brand:

  

• SKU:

  21200-31U1B

• Other Names:

  Engine Thermostat, Coolant Thermostat, Thermostat Assembly, Cooling System Thermostat, OEM Nissan Thermostat

• Description:

  Engine Coolant Thermostat Kit (21200-31U1B)

  OEM Replacement Part for Nissan

  Experiencing engine overheating, fluctuating temperature gauge readings, slow engine warm-up, poor heater performance, or a check engine light related to engine temperature? The Genuine Nissan Engine Coolant Thermostat Kit (21200-31U1B) regulates coolant flow between the engine and radiator, helping your engine reach and maintain its proper operating temperature for optimal performance, fuel efficiency, emissions control, and long-term reliability.

  Engineered to Nissan's exact factory specifications, this OEM thermostat kit opens and closes at the correct operating temperature to provide consistent coolant circulation under all driving conditions. Proper thermostat operation helps protect your engine from overheating while also allowing it to warm up efficiently for maximum performance and reduced engine wear.

  Don't risk ordering the wrong part. Enter your VIN before ordering and a certified Nissan parts specialist will verify the correct thermostat kit for your vehicle before shipment. If another Genuine Nissan part is required for your application, we will contact you before shipping.

  Always verify compatibility by VIN before ordering. Every order is reviewed by a certified Nissan parts specialist before shipping.

  Specifications

  Part Type: Engine Coolant Thermostat Kit

  System: Engine Cooling System

  Function: Regulates coolant flow to maintain proper engine operating temperature

  Construction: Genuine Nissan thermostat with factory-calibrated temperature rating and OEM sealing components

  Location: Engine cooling system

  Included: One (1) Engine Coolant Thermostat Kit

  OEM Type: Genuine Nissan OEM Replacement Part

  VIN Required: Yes

  Compatible Nissan Models

  This Genuine Nissan Engine Coolant Thermostat Kit fits select Nissan vehicles including:

  2004–2027 Nissan Frontier

  2011–2021 Nissan NV

  2012–2021 Nissan NV3500

  2004–2012 Nissan Pathfinder

  2005–2015 Nissan Xterra

  Fitment may vary depending on engine configuration, production date, or cooling system design.

  Enter your VIN before ordering and our Nissan parts specialists will verify the correct thermostat kit for your vehicle prior to shipment.

  Check compatibility here by entering your VIN:

  https://parts.chapmannissan.com

  Key Features

  Genuine Nissan OEM Thermostat Kit Engineered to Nissan factory specifications for precise coolant temperature regulation.

  Maintains Proper Operating Temperature Helps the engine reach and maintain the ideal operating temperature for performance and efficiency.

  Optimizes Cooling System Performance Regulates coolant circulation to help prevent overheating and overcooling.

  Durable OEM Construction Designed to withstand repeated heat cycles for dependable long-term operation.

  Factory-Engineered Fit Designed specifically for compatible Nissan cooling systems.

  Maintenance, Service & Common Symptoms

  • Inspect the thermostat whenever the cooling system is serviced or coolant is replaced.

  • Engine overheating, rapid temperature gauge movement, coolant boil-over, or loss of cabin heat may indicate a thermostat that is stuck closed.

  • Slow engine warm-up, poor heater performance, low operating temperature, or reduced fuel economy may indicate a thermostat that is stuck open.

  • Temperature fluctuations, inconsistent heater output, or recurring cooling system concerns should prompt inspection of the thermostat and related cooling components.

  • Whenever the thermostat is replaced, inspect the engine coolant, radiator hoses, radiator cap, water pump, and cooling fan operation to help ensure complete cooling system reliability.

  Failing to Replace a Faulty Thermostat Can Lead To

  Engine Overheating

  Restricted coolant flow can cause excessive engine temperatures.

  Poor Heater Performance

  Improper coolant circulation can reduce cabin heating.

  Reduced Fuel Economy

  An engine operating below its designed temperature may consume more fuel.

  Engine Performance Issues

  Improper operating temperature can affect emissions, combustion efficiency, and overall engine performance.

  Potential Engine Damage

  Continued overheating may result in cylinder head, head gasket, or internal engine damage.

  Related Components to Inspect or Replace

  Engine Coolant

  Inspect coolant condition and replace if contaminated or due for scheduled maintenance.

  Radiator Cap

  Inspect for proper sealing and pressure retention.

  Upper & Lower Radiator Hoses

  Inspect for leaks, cracking, swelling, or deterioration.

  Water Pump

  Inspect for leaks, bearing noise, or reduced coolant circulation.

  Cooling Fan Assembly

  Verify proper fan operation and radiator airflow.

  Common Symptoms

  Engine overheating

  Temperature gauge running hot

  Temperature gauge fluctuating

  Slow engine warm-up

  Poor cabin heater performance

  Coolant boiling over

  Reduced fuel economy

  Check engine light related to coolant temperature

  Recurring cooling system problems

  Order with Confidence

  Restore proper engine temperature regulation and dependable cooling system performance with the Genuine Nissan Engine Coolant Thermostat Kit (21200-31U1B).

  Enter your VIN before ordering and a certified Nissan parts specialist will verify the correct thermostat kit for your vehicle before shipment. If another Genuine Nissan part is required for your application, we will contact you before shipping.

  All OEM Nissan parts are shipped directly from Chapman Nissan in Philadelphia, PA, and every order is reviewed by a certified Nissan parts specialist before shipping.

  Most OEM Nissan parts ship within 1–3 business days from our certified Nissan warehouse.

  Need assistance before or after ordering?

  https://parts.chapmannissan.com/contact-us

  Phone: 215-492-8900

  Why Buy OEM Nissan Parts from Chapman Nissan?

  Every Genuine Nissan thermostat kit is engineered to factory specifications for precise coolant flow, proper operating temperature, and dependable long-term reliability.

  Unlike some aftermarket thermostats that may open at incorrect temperatures or fail prematurely, Genuine Nissan thermostat kits are designed specifically for Nissan cooling systems to help maximize engine efficiency, heater performance, emissions control, and cooling system durability.

  Our team reviews every order, and VIN verification is available to help ensure you receive the correct Genuine Nissan thermostat kit for your vehicle.

  Fast, secure shipping

  VIN-verified fitment assistance

  Trusted by Nissan owners and professional technicians nationwide

  FAQ

  What does an engine thermostat do?

  The thermostat regulates coolant flow between the engine and radiator to help maintain the proper engine operating temperature.

  What are the symptoms of a bad thermostat?

  Common symptoms include engine overheating, slow warm-up, fluctuating temperature gauge readings, poor heater performance, coolant boil-over, or a check engine light related to engine temperature.

  Can a bad thermostat cause poor heater performance?

  Yes. A thermostat stuck open may prevent the engine from reaching normal operating temperature, reducing cabin heater performance.

  Can a faulty thermostat damage the engine?

  Yes. Continued overheating caused by a thermostat that fails closed can lead to serious engine damage if not corrected promptly.

  Will Chapman Nissan verify the correct thermostat kit for my vehicle?

  Yes. If you provide your VIN when ordering, a certified Nissan parts specialist will verify the correct part before shipment and contact you if another Genuine Nissan part is required.

  Is this a genuine Nissan part?

  Yes. 21200-31U1B is a Genuine Nissan OEM Engine Coolant Thermostat Kit.

• Condition: New
• Applications: 4.0L.
• Replaces:

  2120031u13

• Warranty:

  Warranty Coverage

  This genuine Nissan part is backed by Nissan's nationwide 12-month / 12,000-mile limited replacement parts warranty, subject to Nissan's warranty terms and conditions.

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