Gates 34198 Engine Coolant Thermostat

OE Type Thermostat for GM Cooling Systems

Gates 34198 is an OE Type Engine Coolant Thermostat built for precise temperature control and a leak-free, OEM-equivalent fit. It is a direct replacement choice for a wide range of Chevrolet, GMC, Cadillac, and related GM applications, including Silverado 1500, Sierra 1500, Tahoe, Yukon, and Express van models.

The Gates OE Type Thermostat line focuses on factory-style fit and consistent coolant regulation. For drivers searching for a 187 degree or 190 degree thermostat for GM trucks and SUVs, this part number 34198 provides the OE-style configuration needed for dependable cooling-system service.

Key Features

• OE Type Thermostat with OEM-equivalent fit and temperature control
• Start-to-open temperature: 187°F / 86°C
• Bottom by-pass design for listed GM applications
• Steel and copper construction
• O-ring seal type for leak-resistant sealing
• Jiggle pin weep hole included for air bleeding during service
• OE Performance comparison rating

Detailed Product Overview

Gates part number 34198 is engineered for cooling systems that require accurate thermostat operation to maintain proper engine temperature. Its OE Type design supports factory-style coolant flow control, while the steel and copper construction helps deliver the fit and function expected in everyday repair work. This thermostat is listed across many GM platforms, including 2021-2025 Chevrolet Silverado 2500 HD and Silverado 3500 HD, 2019-2025 GMC Sierra 1500 and Sierra HD models, and 2021-2022 Cadillac Escalade applications.

This part cross-references Motorad 523-190 for the same application.

What It Helps Address

• Engine running too cool or too hot
• Delayed warm-up after cold starts
• Temperature fluctuation from a worn thermostat
• Coolant flow issues caused by a sticking valve
• Leak concerns at the thermostat sealing surface

Installation Notes and Tips

• Verify the OE temperature requirement before installation; this listing includes 187°F and 190°F GM applications.
• Confirm housing style and by-pass configuration before ordering, especially on 2007-2019 Chevrolet and GMC truck and SUV applications.
• Inspect the sealing surface and replace degraded coolant as part of the repair.
• The thermostat uses an O-ring seal; no installation tool is included.
• Fitment includes many Chevrolet Express, Silverado, Tahoe, GMC Savana, Sierra, Yukon, and Cadillac Escalade models across 2007-2025.

Quality Assurance

Gates OE Type Thermostats are built to deliver precise temperature control and an OEM-equivalent fit for service replacement. Part number 34198 is listed with OE Performance comparison and is engineered for consistent cooling-system operation in the specified GM applications.