Calorstat TH6587.87J Engine Coolant Thermostat - Lower

Engine Coolant Thermostat for Mitsubishi and Subaru

Calorstat TH6587.87J is a standard engine coolant thermostat built for precise coolant flow control and stable operating temperature. It opens at 188°F (87°C) and includes a gasket seal for a direct replacement on select Mitsubishi, Subaru, and Scion applications.

Use this thermostat for Mitsubishi Outlander Sport, RVR, and Outlander PHEV coverage, as well as Subaru BRZ, Forester, Impreza, Legacy, Outback, and XV Crosstrek applications listed below. The TH6587.87J part number is also referenced in OE-style cooling system service for multiple Asian vehicles.

Key Features

• Standard engine coolant thermostat for cooling system temperature regulation
• Start-to-open temperature: 188°F / 87°C
• Gasket included for sealing at installation
• Rubber seal material
• Sealing flange outside diameter: 2.2
• Height between flanges: 1.33
• Calorstat TH6587.87J replacement thermostat for select Mitsubishi and Subaru vehicles

Detailed Description

Calorstat TH6587.87J is an engine coolant thermostat engineered to open at 188°F and help maintain the correct operating range in the cooling system. Its standard design, gasket seal, and rubber sealing material support a proper fit in applications that call for this temperature specification. This thermostat is listed for 2025 Mitsubishi Outlander PHEV, 2025 Mitsubishi Outlander Sport, 2025 Mitsubishi RVR, and 2025 Subaru BRZ, along with earlier Mitsubishi and Subaru coverage including Outlander, Lancer, Forester, Impreza, Legacy, Outback, XV Crosstrek, and Scion FR-S. This part cross-references Gates 34817 for the same application.

What It Helps Address

• Engine running too cool or taking too long to reach operating temperature
• Temperature fluctuation caused by a worn thermostat
• Cooling system service on Mitsubishi Outlander Sport, RVR, and Outlander PHEV models
• Cooling system maintenance on Subaru BRZ, Forester, Impreza, Legacy, Outback, and XV Crosstrek models
• Replacement of a thermostat that no longer opens at the specified 188°F / 87°C rating

Installation Notes and Tips

Verify the thermostat housing and engine application before installation, since this part is listed for both N/A and Lower positions depending on vehicle. Confirm the required opening temperature of 188°F / 87°C and match the gasket seal orientation during assembly. Clean the sealing surfaces thoroughly before installing the included gasket to help prevent coolant leaks.

Quality Assurance

Calorstat is listed as an OE supplier to Mitsubishi for several of the covered applications, including Outlander, Outlander Sport, RVR, and Lancer coverage. That OE-supplier background supports the use of this thermostat in service work where the original temperature specification and sealing design must be maintained.