Calorstat THS16965.79 Engine Coolant Thermostat

Engine Coolant Thermostat for BMW M5 and Z8

Calorstat THS16965.79 is a standard engine coolant thermostat built for precise coolant flow control in select BMW applications. It opens at 174.0°F and uses OE-style dimensions to support proper fit in the thermostat and housing assembly.

Compatible with BMW M5 and BMW Z8 applications, this thermostat is a direct-fit cooling system service part for 1991-1993 and 2000-2003 vehicles listed below. Calorstat THS16965.79 also cross-references 11531315063 and 11531407772 for the same application.

Key Features

• Standard engine coolant thermostat for the cooling system
• Start-to-open temperature: 174.0°F
• Sealing flange outside diameter: 2.87 in.
• Height between flanges: 1.45 in.
• By-pass valve diameter: 57.6 mm
• Valve-seat diameter: 73.0 mm
• Height, by-pass side: 37.0 mm
• OE supplier context for BMW applications

Detailed Description

Calorstat THS16965.79 is an engine coolant thermostat designed for BMW cooling system service where accurate temperature regulation matters. The thermostat’s 174.0°F opening point helps manage coolant circulation through the engine and radiator circuit, while the listed flange and valve dimensions support correct housing fitment. This part number is used in BMW M5 and BMW Z8 applications, including 1991-1993 BMW M5 and 2000-2003 BMW M5 and BMW Z8.

This part cross-references 11531315063 and 11531407772 for the same application. Calorstat THS16965.79 is a practical replacement choice when servicing a thermostat that no longer regulates coolant flow correctly in BMW M5 or BMW Z8 cooling systems.

What It Helps Fix

• Engine running too cool or too hot due to thermostat control issues
• Delayed warm-up after cold starts
• Temperature fluctuation from inconsistent coolant flow
• Cooling system service needs tied to thermostat wear
• Fitment concerns when replacing an OE-style BMW thermostat

Installation Notes and Tips

Verify the thermostat housing dimensions and compare the listed measurements before installation. Replace the thermostat only after confirming the cooling system is clean and free of trapped air, and inspect the housing sealing surfaces for damage or corrosion. This part does not include a gasket or seal, so confirm the required sealing components for your application before service.

Fits 1991-1993 BMW M5, N/A. Fits 2000-2003 BMW M5, N/A. Fits 2000-2003 BMW Z8, N/A.

Quality Assurance

Calorstat is identified as an OE supplier to BMW, which supports confidence in application-specific fitment for the listed vehicles. Part number THS16965.79 is built to the stated dimensions and temperature specification for BMW cooling system maintenance.