Motorad 5339-180 Engine Coolant Thermostat

Motorad UltraStat 5339-180 Thermostat Overview

Motorad UltraStat 5339-180 is an engine coolant thermostat built for OE-specified 180°F temperature control in a wide range of GM applications. It combines heavy-gauge stainless steel construction with a rubber seal and jiggle pin weep hole for dependable cooling system service.

Compatible with vehicles such as the Buick Lucerne, Cadillac DTS, Cadillac STS, Cadillac SRX, and Cadillac XLR, this thermostat supports precise coolant flow management for everyday driving and temperature stability. The Motorad UltraStat line focuses on durable construction and controlled opening action to reduce thermal shock to cooling system components.

Key Features

• 180°F engine coolant thermostat for OE-specified applications
• Heavy-gauge stainless steel construction for corrosion resistance
• Includes rubber gasket/seal for installation sealing
• Jiggle pin weep hole helps purge trapped air during filling
• Sealing flange outside diameter: 2.11 in.
• Bypass diameter: 1.38 in.; bypass length: 1.97 in.
• Flange thickness: 0.05 in.
• Motorad UltraStat 5339-180 engineered for controlled coolant regulation

Detailed Description

The Motorad UltraStat 5339-180 engine coolant thermostat is designed for direct-fit cooling system service where a 180°F opening temperature is specified. Its stainless steel construction resists corrosion, while the BLVT valve technology is engineered to moderate coolant flow changes and reduce thermal shock across cooling system components. The included rubber seal supports a proper seal at the housing interface, and the jiggle pin weep hole assists with air bleeding during coolant refill.

This part cross-references 46228 and 95339180 for the same application. It is a practical replacement choice for GM vehicles including the Cadillac DeVille, Cadillac Seville, Oldsmobile Aurora, and Pontiac Bonneville, along with the Buick Lucerne and Cadillac DTS. Use Motorad 5339-180 when the vehicle calls for a 180°F thermostat with the listed dimensions and seal configuration.

Common Cooling System Issues It Can Address

• Engine running cooler or warmer than the specified thermostat temperature
• Delayed coolant circulation after startup
• Temperature fluctuation caused by a sticking thermostat
• Corrosion-related thermostat wear in the cooling system
• Air pockets in the cooling system after service

Installation Notes and Tips

Install Motorad UltraStat 5339-180 only in applications that specify a 180°F thermostat and the listed fitment. Clean the thermostat housing sealing surface before installation, and verify the rubber seal is seated correctly before reassembly. During refill, allow the jiggle pin weep hole to assist with air bleeding, then follow the vehicle manufacturer’s coolant fill and bleed procedure.

Quality Assurance

Motorad UltraStat thermostats use stainless steel construction for long-life durability and corrosion resistance. The BLVT valve design is part of the UltraStat product line and is intended to support smoother coolant flow control in the cooling system.