Motorad 7339-180 Engine Coolant Thermostat

Engine Coolant Thermostat Overview

The Motorad Fail-Safe 7339-180 engine coolant thermostat is built for OE-style temperature control in demanding cooling systems. It opens at 180°F and uses a fail-safe, lock-open design to maintain coolant flow during overheating events, making it a direct-fit choice for many Cadillac, Buick, Pontiac, and Oldsmobile applications.

Motorad 7339-180 is manufactured with OEM-quality materials and processes, including a copper case and wax compound for quick response to coolant temperature changes. The included rubber seal, jiggle pin weep hole, offset design, and air relief valve support consistent installation and reliable cooling-system operation.

Key Features

• 180°F thermostat temperature for OE-specified engine warm-up control
• Fail-Safe lock-open design for continuous coolant flow during overheating
• Copper case and wax compound for rapid reaction to coolant temperature changes
• Offset design with air relief valve where applicable
• Gasket/seal included; rubber seal material
• Jiggle pin weep hole for air bleeding during service
• Sealing flange outside diameter: 2.11 in
• Bypass diameter: 1.38 in; bypass length: 1.58 in
• Flange thickness: 0.05 in

Detailed Description

This Motorad Fail-Safe thermostat is engineered for vehicles that require stable coolant regulation and OE-style fitment. It is a strong match for long-tail searches such as 180 degree engine coolant thermostat for 2006-2011 Buick Lucerne, 2006-2011 Cadillac DTS, and 2004-2009 Cadillac SRX. It also serves applications including Cadillac DeVille, Cadillac Seville, Cadillac Eldorado, Cadillac XLR, Pontiac Bonneville, Oldsmobile Aurora, and Cadillac Allante. This part cross-references Four Seasons 73398 for the same application.

Motorad’s Fail-Safe product line is designed around a lock-in open position strategy, so if overheating occurs the thermostat remains open to help keep coolant moving through the system. That makes Motorad 7339-180 a practical replacement for drivers seeking OE-style temperature control in GM cooling systems.

What It Helps Address

• Engine overheating caused by a thermostat that no longer opens correctly
• Slow engine warm-up or unstable operating temperature
• Coolant flow interruption from a sticking thermostat
• Air pockets in the cooling system during service
• Leak concerns at the thermostat seal interface

Installation Notes

Verify the 180°F temperature rating and housing dimensions before installation. Use the included seal and confirm the sealing flange, bypass dimensions, and offset design match the original thermostat specification. The jiggle pin weep hole should be oriented to help purge trapped air during filling and bleeding. For best results, inspect the thermostat housing, coolant condition, and related seals before reassembly.

Compatible With 2006-2011 Buick Lucerne, 2006-2011 Cadillac DTS, 2005-2010 Cadillac STS, 2004-2009 Cadillac SRX, 2004-2009 Cadillac XLR, 1994-2005 Cadillac DeVille, 2004-2005 Pontiac Bonneville, 1993-2004 Cadillac Seville, 2001-2003 Oldsmobile Aurora, 1995-1999 Oldsmobile Aurora, 1993-2002 Cadillac Eldorado, and 1993 Cadillac Allante.

Quality Assurance

Motorad manufactures this thermostat to OEM specifications and processes using OE-supplier quality materials and safety standards. The copper case, wax compound, and OE-style sealing approach are intended to support consistent cooling-system performance in the listed applications.