Calorstat TH5902.87J Engine Coolant Thermostat

Engine Coolant Thermostat for Audi and Volkswagen

Calorstat TH5902.87J is a standard engine coolant thermostat built for precise coolant flow control in select Audi and Volkswagen applications. It includes an O-ring seal and gasket/seal, plus a jiggle pin weep hole for easier air bleeding during service.

Key Features

• Standard engine coolant thermostat for temperature regulation
• Start to open temperature: 188.0°F
• O-ring seal material with gasket or seal included
• Jiggle pin weep hole for air purge during installation
• By-pass valve diameter: 35.0 mm
• Valve-seat diameter: 67.0 mm
• Sealing flange outside diameter: 2.63 in.
• Height between flanges: 1 in.

Detailed Description

Calorstat TH5902.87J is an engine coolant thermostat for Audi A4, Audi A6 Quattro, Audi Allroad Quattro, and related Volkswagen Passat applications listed below. It opens at 188.0°F to help regulate coolant circulation and maintain proper operating temperature in the cooling system. The included O-ring seal and rubber sealing material support a secure fit at the housing interface, while the jiggle pin weep hole helps trapped air escape during refill and bleeding. This part cross-references Stant 48049 for the same application.

What It Helps Address

• Engine running too cool or too hot due to thermostat control issues
• Delayed warm-up after cold starts
• Temperature fluctuation from a sticking thermostat
• Coolant flow irregularities in the thermostat housing area
• Air pockets during cooling system service

Installation Notes and Tips

• Verify housing condition and sealing surfaces before installation.
• Replace the thermostat only with the correct temperature and dimensions for the application.
• Orient the jiggle pin weep hole as required by the vehicle service procedure.
• Refill and bleed the cooling system carefully to remove trapped air.
• Confirm fitment for the exact Audi or Volkswagen model and year before ordering.

Quality Assurance

Calorstat is listed as an OE supplier to Audi and Volkswagen for the covered applications, supporting confidence in fitment and cooling-system service accuracy. Part number TH5902.87J is referenced for multiple import cooling-system applications, including Audi A4, Audi A6, and Volkswagen Passat coverage shown in the fitment data.

Compatible Vehicles

• Fits 2001-2005 Audi Allroad Quattro, N/A
• Fits 1995-2004 Audi A6 Quattro, N/A
• Fits 2000-2002 Audi S4, N/A
• Fits 1996-1999 Audi A4, N/A
• Fits 1996-1999 Audi A4 Quattro, N/A
• Fits 1995-1999 Audi A6, N/A
• Fits 1997-1999 Audi A8, N/A
• Fits 1997-1999 Audi A8 Quattro, N/A
• Fits 1998-1999 Volkswagen Passat, N/A
• Fits 1994-1998 Audi Cabriolet, N/A
• Fits 1993-1995 Audi 90, N/A
• Fits 1993-1995 Audi 90 Quattro, N/A
• Fits 1992-1994 Audi 100, N/A
• Fits 1992-1994 Audi 100 Quattro, N/A
• Fits 1990-1994 Audi V8 Quattro, N/A