Mishimoto 2003+ Toyota 4Runner 4.0L Low-Temperature Racing Thermostat - MMTS-4RUN40-03 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... $105.16 Add to Cart The item has been added Compare