Mishimoto misMMTS-4RUN40-03 2003+ Toyota 4Runner 4.0L Low-Temperature Racing Thermostat

A defective thermostat can result in engine overheating and potential internal damage. Improve the reliability of your 2003-2024 Toyota 4Runner 4.0L cooling system with a Mishimoto Low-Temperature Racing Thermostat and housing! This thermostat is designed as a direct-fit replacement for your aged stock unit. The Mishimoto thermostat has a lower activation temperature (71?C/160?F) compared to the factory thermostat (82?C/180?F). The lower activation temperature allows coolant to flow through the engine earlier, which reduces and maintains lower engine temperatures. This thermostat is ideal for use in warmer climates, on vehicles making more power than stock, or under extreme towing/driving conditions. The stock-style housing will provide a proper seal and installs easily. Like all our Toyota Performance parts, this thermostat and housing includes the Mishimoto Lifetime Warranty. Engine coolant thermostat designed to regulate coolant flow and maintain optimal operating temperature. Ensures efficient warm-up, prevents overheating, and supports reliable performance with a precise fit.

• The lower activation temperature allows coolant to flow through the engine earlier, which reduces and maintains lower engine temperatures. (71C/160F compared to the factory thermostat at 82C/180F)
• Ideal for use in hot climates, on modified vehicles, or in extreme towing/driving conditions
• Stock-style housing includes pre-installed low-temperature thermostat for easy install

Brief Description: The Mishimoto misMMTS-4RUN40-03 Low-Temperature Racing Thermostat and housing is designed as a direct-fit replacement for the stock thermostat in 2003–2024 Toyota 4Runner models with the 4.0L engine. Its 71°C/160°F activation temperature allows coolant to flow through the engine earlier than the factory 82°C/180°F thermostat, helping reduce and maintain lower engine temperatures.

Key Features & Performance Benefits:

• Lower Activation Temperature: Opens at 71°C/160°F compared with the factory 82°C/180°F thermostat.
• Earlier Coolant Flow: Helps circulate coolant through the engine earlier to support lower operating temperatures.
• Stock-Style Housing: Provides a proper seal and supports straightforward installation.
• Performance-Oriented Design: Suitable for hot climates, modified vehicles, and extreme towing or driving conditions.

Key Product Specifications & Technical Data:

• Brand: Mishimoto
• Part Number: misMMTS-4RUN40-03
• Product Type: Low-temperature racing thermostat and housing
• Application: Toyota 4Runner 4.0L
• Thermostat Activation Temperature: 71°C/160°F
• Factory Thermostat Comparison: 82°C/180°F
• Housing Style: Stock-style
• Warranty: Mishimoto Lifetime Warranty

What's Included in the Box: One Mishimoto low-temperature thermostat with stock-style housing and pre-installed thermostat.

Fitment: Product data identifies fitment for Toyota 4Runner models from 2003–2024 with the 4.0L engine and lists select Toyota Tacoma and Toyota 4Runner applications, including 2005–2008 Toyota Tacoma and 2010–2011 Toyota 4Runner models. Verify vehicle application before installation.

Fitments:
2003 Toyota 4Runner Limited
2003 Toyota 4Runner Sport
2003 Toyota 4Runner SR5
2004 Toyota 4Runner Limited
2004 Toyota 4Runner Sport
2004 Toyota 4Runner SR5
2005 Toyota 4Runner Limited
2005 Toyota 4Runner Sport
2005 Toyota 4Runner SR5
2005 Toyota Tacoma Base
2005 Toyota Tacoma Pre Runner
2005 Toyota Tacoma X-Runner
2005 Toyota Tundra Base
2005 Toyota Tundra SR5
2006 Toyota 4Runner Limited
2006 Toyota 4Runner Sport
2006 Toyota 4Runner SR5
2006 Toyota Tacoma Base
2006 Toyota Tacoma Pre Runner
2006 Toyota Tacoma X-Runner
2006 Toyota Tundra Base
2006 Toyota Tundra SR5
2007 Toyota 4Runner Limited
2007 Toyota 4Runner Sport
2007 Toyota 4Runner SR5
2007 Toyota FJ Cruiser Base
2007 Toyota FJ Cruiser TRD Special Edition
2007 Toyota Tacoma Base
2007 Toyota Tacoma Pre Runner
2007 Toyota Tacoma X-Runner
2007 Toyota Tundra Base
2007 Toyota Tundra SR5
2008 Toyota 4Runner Limited
2008 Toyota 4Runner Sport
2008 Toyota 4Runner SR5
2008 Toyota FJ Cruiser Base
2008 Toyota FJ Cruiser Trail Teams Special Edition
2008 Toyota Tacoma Base
2008 Toyota Tacoma Pre Runner
2008 Toyota Tacoma X-Runner
2008 Toyota Tundra Base
2008 Toyota Tundra SR5
2009 Toyota 4Runner Limited
2009 Toyota 4Runner Sport
2009 Toyota 4Runner SR5
2009 Toyota FJ Cruiser Base
2009 Toyota Tacoma Base
2009 Toyota Tacoma Pre Runner
2009 Toyota Tacoma X-Runner
2009 Toyota Tundra Base
2009 Toyota Tundra SR5
2010 Toyota 4Runner Limited
2010 Toyota 4Runner SR5
2010 Toyota 4Runner Trail
2010 Toyota FJ Cruiser Base
2010 Toyota Tacoma Base
2010 Toyota Tacoma Pre Runner
2010 Toyota Tacoma X-Runner
2010 Toyota Tundra Base
2010 Toyota Tundra SR5
2011 Toyota 4Runner Limited
2011 Toyota 4Runner SR5
2011 Toyota 4Runner Trail
2011 Toyota FJ Cruiser Base
2011 Toyota Tacoma Base
2011 Toyota Tacoma Pre Runner
2011 Toyota Tacoma X-Runner
2011 Toyota Tundra Base
2011 Toyota Tundra SR5
2012 Toyota 4Runner Limited
2012 Toyota 4Runner SR5
2012 Toyota 4Runner Trail
2012 Toyota FJ Cruiser Base
2012 Toyota Tacoma Base
2012 Toyota Tacoma Pre Runner
2012 Toyota Tacoma X-Runner
2012 Toyota Tundra Base
2013 Toyota 4Runner Limited
2013 Toyota 4Runner SR5
2013 Toyota 4Runner Trail
2013 Toyota FJ Cruiser Base
2013 Toyota Tacoma Base
2013 Toyota Tacoma Pre Runner
2013 Toyota Tacoma X-Runner
2013 Toyota Tundra Base
2014 Toyota 4Runner Limited
2014 Toyota 4Runner SR5
2014 Toyota 4Runner Trail
2014 Toyota FJ Cruiser Base
2014 Toyota Tacoma Base
2014 Toyota Tacoma Pre Runner
2014 Toyota Tundra SR
2015 Toyota 4Runner Limited
2015 Toyota 4Runner SR5
2015 Toyota 4Runner Trail
2015 Toyota 4Runner TRD Pro
2015 Toyota Tacoma Base
2015 Toyota Tacoma Pre Runner
2015 Toyota Tacoma TRD Pro
2016 Toyota 4Runner Limited
2016 Toyota 4Runner SR5
2016 Toyota 4Runner Trail
2016 Toyota 4Runner TRD Pro
2017 Toyota 4Runner Limited
2017 Toyota 4Runner SR5
2017 Toyota 4Runner TRD Off-Road
2017 Toyota 4Runner TRD Pro
2018 Toyota 4Runner Limited
2018 Toyota 4Runner SR5
2018 Toyota 4Runner SR5 Premium
2018 Toyota 4Runner TRD Off-Road
2018 Toyota 4Runner TRD Off-Road Premium
2018 Toyota 4Runner TRD Pro
2019 Toyota 4Runner Limited
2019 Toyota 4Runner SR5
2019 Toyota 4Runner SR5 Premium
2019 Toyota 4Runner TRD Off-Road
2019 Toyota 4Runner TRD Off-Road Premium
2019 Toyota 4Runner TRD Pro
2020 Toyota 4Runner Limited
2020 Toyota 4Runner Nightshade
2020 Toyota 4Runner SR5
2020 Toyota 4Runner SR5 Premium
2020 Toyota 4Runner TRD Off-Road
2020 Toyota 4Runner TRD Off-Road Premium
2020 Toyota 4Runner TRD Pro
2020 Toyota 4Runner Venture
2021 Toyota 4Runner Limited
2021 Toyota 4Runner Nightshade
2021 Toyota 4Runner SR5
2021 Toyota 4Runner SR5 Premium
2021 Toyota 4Runner Trail
2021 Toyota 4Runner TRD Off-Road
2021 Toyota 4Runner TRD Off-Road Premium
2021 Toyota 4Runner TRD Pro
2021 Toyota 4Runner Venture
2022 Toyota 4Runner Limited
2022 Toyota 4Runner SR5
2022 Toyota 4Runner SR5 Premium
2022 Toyota 4Runner Trail
2022 Toyota 4Runner TRD Off-Road
2022 Toyota 4Runner TRD Off-Road Premium
2022 Toyota 4Runner TRD Pro
2022 Toyota 4Runner TRD Sport
2023 Toyota 4Runner 40th Anniversary Edition
2023 Toyota 4Runner Limited
2023 Toyota 4Runner SR5
2023 Toyota 4Runner SR5 Premium
2023 Toyota 4Runner TRD Off-Road
2023 Toyota 4Runner TRD Off-Road Premium
2023 Toyota 4Runner TRD Pro
2023 Toyota 4Runner TRD Sport
2024 Toyota 4Runner Limited
2024 Toyota 4Runner SR5
2024 Toyota 4Runner SR5 Premium
2024 Toyota 4Runner TRD Off-Road
2024 Toyota 4Runner TRD Off-Road Premium
2024 Toyota 4Runner TRD Pro
2024 Toyota 4Runner TRD Sport

Air Freight Prohibited: false
Not Carb Approved: false
Ltl Freight Required: false
Prop 65: Y
Part Type: automotive
Epa: N/A
Carb Acknowledgement Required: false
Regular Stock: t
Units Per Sku: 1