Dorman 902-5025 Engine Coolant Thermostat Housing

Engine Coolant Thermostat Housing for BMW Cooling Systems

Dorman 902-5025 is a replacement engine coolant thermostat housing built to match the fit and durability of the original housing on specified BMW applications. It uses a plastic construction with a natural finish and a 90-degree housing neck angle to support proper coolant routing in the engine cooling system.

Compatible With BMW 740iL, 530i, 540i, 740i, and 840Ci applications listed below, this thermostat housing is made for vehicles that need a direct replacement housing without the thermostat. The Dorman 902-5025 housing is shaped for the specified mounting pattern and outlet size to help restore cooling system function.

• Plastic thermostat housing with natural color finish
• 1.5 in. outlet port diameter
• 4 mounting holes with 0.313 in. mounting hole diameter
• 90-degree housing neck angle
• Thermostat not included
• Gasket included with the housing
• No bleeder valve, no bolts included, and no O-rings required

Detailed Product Overview

This engine coolant thermostat housing is engineered for BMW cooling system service where the original housing has cracked, warped, or degraded from heat cycling. Dorman 902-5025 is a direct-fit replacement for the specified BMW 740iL, 530i, 540i, 740i, and 840Ci models, with fitment covering 1993-1996 applications depending on model. It is designed to withstand repeated temperature changes and maintain service life in demanding underhood conditions.

This part cross-references Beck/Arnley 147-0017 for the same application.

Common Reasons for Replacement

• Coolant leaks at the thermostat housing
• Cracked or brittle plastic housing
• Warped sealing surface causing seepage
• Cooling system service on BMW 740iL, 530i, 540i, 740i, or 840Ci
• Housing damage from repeated heat cycling

Installation Notes and Tips

Verify the vehicle application before installation. This housing is listed for BMW 740iL, 530i, 540i, 740i, and 840Ci models with the noted fitment, and it is supplied without the thermostat. Inspect the mating surfaces, coolant hoses, and adjacent cooling system components before assembly so the replacement housing can seal correctly.

Use the included gasket during installation and confirm the outlet orientation matches the original layout. Because this housing has no bleeder valve and no bolts are included, reuse or source the correct service parts as required by the vehicle.

Quality Assurance

Dorman designs this replacement thermostat housing to match stock fit and durability for the specified vehicles. The housing is built to handle extreme temperature changes in the cooling system, supporting long-term service in BMW applications such as the 1993-1996 740iL and related models.