Motorad 5339-180 Engine Coolant Thermostat

Reliable Engine Coolant Thermostat for Buick, Cadillac, Oldsmobile, and Pontiac

The Motorad UltraStat 5339-180 engine coolant thermostat is designed to maintain optimal engine temperature for select Buick, Cadillac, Oldsmobile, and Pontiac models. Engineered to precise specifications, this thermostat ensures efficient coolant flow and temperature regulation at 180 degrees Fahrenheit.

• Sealing flange outside diameter: 2.11 inches
• Includes one rubber gasket/seal for secure installation
• Jiggle pin weep hole for air and vapor release
• Bypass diameter of 1.38 inches and bypass length of 1.97 inches
• Flange thickness of 0.05 inches for proper fitment
• Temperature rating: 180°F for consistent engine performance

About the Motorad UltraStat Product Line

The UltraStat line by Motorad focuses on delivering thermostats that meet or exceed OEM specifications for temperature control and durability. This product line emphasizes precise temperature regulation and reliable sealing, which are critical for maintaining engine efficiency and preventing overheating or overcooling in vehicles like the Cadillac DeVille and Pontiac Bonneville.

Detailed Product Description

The Motorad UltraStat 5339-180 thermostat features a 2.11-inch sealing flange outside diameter and includes a single rubber gasket to ensure a tight seal within the cooling system. The jiggle pin weep hole allows trapped air and vapor to escape, reducing the risk of air pockets that can affect coolant flow. With a bypass diameter of 1.38 inches and a bypass length of 1.97 inches, this thermostat supports proper coolant circulation during engine warm-up. The flange thickness of 0.05 inches ensures a secure fit in the thermostat housing. Rated for 180 degrees Fahrenheit, this thermostat is engineered to open at the correct temperature to maintain optimal engine operating conditions.

Compatible Vehicles and Common Applications

• Buick Allante and Lucerne
• Cadillac DeVille, DTS, Eldorado, Seville, SRX, STS, and XLR
• Oldsmobile Aurora
• Pontiac Bonneville

• Helps prevent engine overheating by regulating coolant flow
• Reduces engine warm-up time for improved fuel efficiency
• Prevents coolant leaks with included rubber gasket
• Minimizes air pockets in the cooling system via jiggle pin weep hole
• Supports consistent engine temperature for reliable performance

Installation Notes and Tips

This thermostat does not include an installation tool, so ensure you have the appropriate tools for removal and installation. When replacing the thermostat, inspect the housing and coolant passages for debris or corrosion. Use the included rubber gasket to create a proper seal and prevent leaks. Verify the thermostat is oriented correctly with the jiggle pin weep hole positioned to allow air release. Follow vehicle-specific service manual instructions for torque specifications and installation procedures.

Quality Assurance and Warranty

Motorad UltraStat thermostats are manufactured to meet strict quality standards and OEM specifications. The 5339-180 thermostat is designed for durability and reliable temperature control. While specific warranty details are not provided, Motorad products typically come with manufacturer-backed quality assurance to support long-term performance in compatible Buick, Cadillac, Oldsmobile, and Pontiac vehicles.