Subaru OEM Engine Coolant Thermostat Kit | 21210AA181

Overview

The Genuine Subaru OEM Thermostat (Part #21210AA181) is the factory-original cooling system component designed specifically for 2013–2020 and 2022–2027 Subaru BRZ and 2011–2018 Subaru Forester models. Engineered to maintain optimal engine operating temperature, this thermostat ensures precise coolant flow regulation for peak performance and long-term engine health. If you're replacing a worn or failed thermostat on your BRZ, this is the exact-fit, factory-warranty-backed part Subaru uses at the assembly line.

Key Features & Benefits

• Genuine Subaru OEM Quality – Manufactured to factory specifications, guaranteeing correct fit, function, and durability that aftermarket parts cannot match.
• Exact-Fit Replacement – Designed specifically for compatible Subaru models; installs without modification for a hassle-free repair.
• Optimal Engine Temperature Regulation – Opens and closes at the factory-calibrated temperature to maintain ideal coolant flow, protecting your engine from overheating or running too cool.
• Factory Warranty Coverage – Backed by Subaru's genuine parts warranty, giving you confidence in every mile driven after installation.
• Prevents Costly Engine Damage – A properly functioning thermostat safeguards your BRZ's engine by preventing thermal stress and maintaining fuel efficiency.
• Direct OEM Cross-Reference – Subaru Part Number 21210AA181; matches the original component installed at the factory.

What's Included

• 1x Genuine Subaru Thermostat – Part #21210AA181

Specifications

Fitment & Compatibility

This Genuine Subaru Thermostat (21210AA181) is compatible with the following vehicles:

2013-2020 Subaru BRZ

2022-2027 Subaru BRZ

2011-2018 Subaru Forester

Always verify your vehicle's VIN and model year before ordering. Confirm compatibility using your VIN to ensure exact fit for your specific Subaru application.

Installation

The Subaru BRZ thermostat replacement is an intermediate-level DIY procedure. The thermostat is located within the engine cooling system and requires draining of coolant prior to removal. Torque specifications and coolant refill procedures should be followed per the Subaru BRZ factory service manual. Professional installation by a Subaru-trained technician is recommended if you are unfamiliar with cooling system service. Upon completion, always check for leaks and verify proper engine warm-up cycle before returning the vehicle to normal operation.