Calorstat TH6578.87J Engine Coolant Thermostat

Engine Cooling Control for Ford, Mazda, and GM Applications

The Calorstat TH6578.87J engine coolant thermostat is a standard replacement thermostat built for precise coolant flow control in a wide range of Ford, Mazda, Mercury, Jaguar, Chevrolet, GMC, Lincoln, Cadillac, and Oldsmobile applications. With an 188°F opening temperature, it supports stable operating temperature for vehicles such as the Ford Escape, Ford Fusion, and Mazda Tribute.

• Standard engine coolant thermostat for OE-style temperature regulation
• Start to open temperature: 188.0°F / 87°C
• Gasket or seal included for a cleaner service installation
• O-ring seal type with rubber seal material
• Jiggle pin weep hole for air bleeding during coolant service
• Sealing flange outside diameter: 2.12 in.
• Height between flanges: 1.57 in.
• By-pass valve diameter: 35.0 mm
• Valve-seat diameter: 54.0 mm

Detailed Product Overview

Calorstat TH6578.87J is an engine coolant thermostat designed around the listed dimensions and 188°F opening point to help maintain proper coolant circulation once the engine reaches operating temperature. The included O-ring seal and gasket/seal support a direct-fit service replacement, while the jiggle pin weep hole helps purge trapped air from the cooling system during refill. This part cross-references Gates 33248 and Motorad 354-192 for the same application.

Compatible vehicle coverage includes long-tail search applications such as 2005-2012 Ford Escape thermostat replacement, 2006-2012 Ford Fusion coolant thermostat, and 2001-2004 Mazda Tribute engine thermostat service. It also appears in applications for Ford F-150, Ford Mustang, Mercury Mariner, Jaguar S-Type, and Chevrolet Astro cooling system repairs.

Common Problems This Part Can Address

• Engine running too cool or taking too long to reach operating temperature
• Temperature fluctuation caused by a worn thermostat
• Coolant flow issues after cooling system service
• Air pockets in the cooling system during refill
• Thermostat housing service requiring a new seal

Installation Notes and Tips

Verify the thermostat dimensions, bypass valve diameter, and valve-seat diameter against the original part before installation. Clean the housing sealing surfaces thoroughly, install the included seal correctly, and refill the cooling system with the proper coolant mixture. After installation, bleed air from the system and confirm normal operating temperature during a road test.

Quality Assurance

Calorstat is listed as an OE supplier to Ford and GM in the provided fitment data, and this thermostat is specified with application-matched dimensions for the vehicles shown. Confirm fitment by year, make, model, and cooling system configuration before ordering. Fits 2005-2012 Ford Escape, 2006-2012 Ford Fusion, and other listed Ford, Mazda, Mercury, Jaguar, Chevrolet, GMC, Lincoln, Cadillac, and Oldsmobile applications.