Gates 34027 Engine Coolant Thermostat

Gates OE Type Thermostat 34027 Overview

The Gates OE Type Thermostat 34027 is built for precise engine temperature control and an OEM-equivalent fit. It is a direct replacement engine coolant thermostat for select BMW applications, including BMW Z3, BMW M3, BMW 318i, BMW 318is, BMW 318ti, BMW 325i, BMW 325is, BMW 525i, and BMW 525iT.

Gates OE Type Thermostat products are engineered for consistent opening temperature control and a leak-resistant seal interface. The 34027 thermostat is a 190-degree OE temperature unit with a bottom by-pass design, steel and copper construction, and an O-ring seal type.

Key Features

• OE Type Thermostat for OEM-equivalent fit and temperature control
• 190-degree start-to-open temperature for factory-style cooling system operation
• Bottom by-pass design for the listed BMW cooling system applications
• Steel and copper construction for durable service in the cooling circuit
• O-ring seal type for a secure sealing interface
• No jiggle pin weep hole and no installation tool included
• Gates part number 34027 for easy catalog matching

Detailed Description

The Gates 34027 thermostat is a direct-fit engine coolant thermostat for BMW cooling systems that call for a 190-degree OE temperature specification. It is designed to regulate coolant flow so the engine reaches and maintains the proper operating temperature, which is important for stable warm-up, heater performance, and consistent cooling system behavior. The OE Type Thermostat line from Gates focuses on factory-style fit and temperature control, making this part a practical replacement for service work on BMW Z3, BMW M3, BMW 318i, BMW 318is, BMW 318ti, BMW 325i, BMW 325is, BMW 525i, and BMW 525iT applications.

This thermostat uses a bottom by-pass design, a steel and copper body, and an O-ring seal. The sealing flange outside diameter measures 2.61 inches, with a height of 2.24 inches and a height between flanges of 1.11 inches. Gates part number 34027 is also referenced in OE-style cooling system catalogs for the same application.

What It Helps Address

• Engine running too cool or taking too long to reach operating temperature
• Temperature fluctuation caused by a worn thermostat
• Coolant flow control issues in the thermostat housing circuit
• Heater output problems related to delayed engine warm-up
• Cooling system service needs on BMW Z3 and BMW 3 Series/5 Series applications

Installation Notes and Tips

Verify the OE temperature specification and housing style before installation. This thermostat is listed with a 190-degree start-to-open temperature and a bottom by-pass design, so matching the original configuration is important for proper operation. Inspect the sealing surfaces, replace the O-ring seal as required by the application, and confirm the thermostat seats correctly in the housing before refilling and bleeding the cooling system.

Compatible With 2001 BMW Z3, N/A; 2000 BMW Z3, N/A; 1995-1999 BMW M3, N/A; 1991-1995 BMW 318i, N/A; 1991-1995 BMW 318is, N/A; 1995 BMW 318ti, N/A; 1993-1995 BMW 325i, N/A; 1992-1995 BMW 325is, N/A; 1992-1995 BMW 525i, N/A; 1993 BMW 525iT, N/A.

Quality Assurance

Gates OE Type Thermostats are built to deliver precise temperature control and an OEM-equivalent fit for the listed applications. The 34027 is manufactured to support reliable cooling system service on BMW models that require the specified OE-style thermostat design.