Motorad 274-174 Engine Coolant Thermostat

Engine Coolant Thermostat for BMW Cooling Systems

Motorad Standard 274-174 is an engine coolant thermostat built for BMW cooling systems that need precise temperature control. This 170 degree F thermostat uses OEM-quality materials and OE-supplier manufacturing processes to support consistent coolant flow and stable operating temperature.

Compatible With BMW Z3, 323is, 323ti, 328i, 328is, M3, 323i, 850Ci, 320i, 325i, 525i, 325is, 535i, M5, 735i, 735iL, 325iX, 635CSi, 528e, 535is, M6, and 325e applications across the listed model years. Part number 274-174 is also cross-referenced to Gates 34760 for the same application.

Key Features

• 170 degree F opening temperature for controlled coolant regulation
• Copper case and wax compound for quick response to coolant temperature changes
• Manufactured to OEM specifications and processes
• OE-supplier quality materials and safety standards
• Offset design with air relief valve and OEM-style seals where applicable
• Sealing flange outside diameter: 2.64 in
• Bypass diameter: 1.30 in
• Bypass length: 1.02 in
• Flange thickness: 0.05 in

Detailed Description

Motorad Standard 274-174 is an engine coolant thermostat for BMW models that require a 170 degree F thermostat setting. The copper case and wax compound are engineered for fast reaction to coolant temperature changes, helping the cooling system maintain the correct operating range during daily driving and demanding conditions. The offset design and air relief valve support proper coolant movement during service, while OEM-style sealing features are used where applicable. This part number 274-174 is a direct-fit style replacement for a wide range of BMW cooling system applications, including BMW M3, 325i, 525i, and 735i models.

What It Helps Address

• Engine running too cool or too warm due to thermostat wear
• Delayed coolant circulation after startup
• Temperature fluctuation in BMW cooling systems
• Cooling system service on older BMW 3 Series, 5 Series, 7 Series, and M models
• Replacement of a thermostat with incorrect opening temperature

Installation Notes and Tips

Verify the 170 degree F temperature rating and compare the sealing flange, bypass dimensions, and housing style before installation. This thermostat does not include a gasket or seal, and no installation tool is included. Clean the mating surfaces thoroughly and inspect the housing and coolant passages before reassembly. Confirm vehicle-specific fitment for your BMW Z3, M3, 328i, or other listed application before service.

Quality Assurance

Motorad Standard thermostats are manufactured to OEM-quality materials and safety standards by an OE supplier. The Standard line focuses on OE-style replacement parts built to match factory specifications for cooling system service.