Motorad 288-185 Engine Coolant Thermostat

Engine Coolant Thermostat for BMW Cooling Systems

Motorad Standard 288-185 is an engine coolant thermostat built to OE specifications for BMW cooling system service. It uses a copper case and wax compound for quick reaction to coolant temperature changes, and it includes an O-ring seal, jiggle pin weep hole, and OEM-style sealing details where applicable.

Compatible With BMW 850Ci, 840Ci, 530i, 540i, 740i, 740iL, 850CSi, 750iL, and 850i applications across the listed model years, this thermostat is specified at 180 degrees F for controlled engine warm-up and stable operating temperature. Motorad 288-185 is a direct-fit service part for select BMW cooling system repairs.

Key Features

• 180 degree F start-to-open temperature
• OE supplier construction with OEM quality materials and processes
• Copper case and wax compound for responsive temperature control
• Offset design with air relief valve and OEM-style seals where applicable
• O-ring seal included with rubber sealing material
• Jiggle pin weep hole for air bleeding during service
• Standard type thermostat for select BMW cooling systems

Detailed Description

This Motorad Standard thermostat is engineered for BMW engines that require precise coolant regulation. The 180 degree F calibration helps the cooling system reach and maintain the intended operating range, while the copper case and wax element respond quickly to coolant temperature changes. Dimensions such as the 3.31 in sealing flange outside diameter, 2.23 in height, and 1.56 in height between flanges support OE-style fitment in the listed applications. This part cross-references BMW OE-style applications such as 172286 and 182286 for the same application.

Fits 1997-1998 BMW 850Ci, N/A; Fits 1993-1995 BMW 850Ci, N/A; Fits 1994-1997 BMW 840Ci, N/A; Fits 1994-1995 BMW 530i, N/A; Fits 1994-1995 BMW 540i, N/A; Fits 1993-1995 BMW 740i, N/A; Fits 1993-1995 BMW 740iL, N/A; Fits 1994-1995 BMW 850CSi, N/A; Fits 1988-1994 BMW 750iL, N/A; Fits 1991-1992 BMW 850i, N/A.

Common Cooling System Issues It May Solve

• Engine running too cool or taking too long to warm up
• Temperature fluctuations caused by a worn thermostat
• Coolant flow control problems in BMW cooling systems
• Air trapped in the cooling circuit after thermostat service
• Improper sealing at the thermostat housing interface

Installation Notes and Tips

Verify the 180 degree F specification and compare the thermostat dimensions to the removed part before installation. Replace the seal during service, clean the housing mating surfaces, and confirm the jiggle pin orientation follows the vehicle service procedure so trapped air can escape properly. Motorad 288-185 is intended for the listed BMW applications only, including BMW 850Ci and BMW 740i models shown in the fitment data.

Quality Assurance

Motorad manufactures this thermostat as an OE-supplier part using OEM-quality materials and safety standards. It is built to OEM specifications and processes for consistent cooling system service in the listed BMW applications.