Engine Coolant Thermostat Kit, LML Duramax | 2011-2016

Does your engine take a long time to warm up or never seem to reach operating temperature? A worn thermostat stuck open is a common cause. The Merchant Automotive Engine Coolant Thermostat Kit includes both thermostats and the oil fill tube seal for 2011-2016 Chevy Silverado and GMC Sierra 2500HD and 3500HD trucks with the 6.6L LML Duramax diesel and 2011-2016 Chevy Express and GMC Savana vans with the 6.6L LGH Duramax.

Features

• Front thermostat, opens at 185 degrees
• Rear thermostat with built-in bleeder valves, opens at 180 degrees
• Includes the oil fill tube seal

What's Included

• (1) Front thermostat, 185 degrees (131-163)
• (1) Rear thermostat, 180 degrees (131-131)
• (1) Oil fill tube seal (94007612)

Which Thermostat Goes Where

The front thermostat mounts in the forward position of the thermostat housing and is identified by its symmetrical shape. It opens at 185 degrees, allowing coolant to flow to the radiator. The rear thermostat sits toward the firewall. It is identified by its offset design and has bleeder valves built in. It opens at 180 degrees.

When to Replace

Replace the thermostats if the engine is slow to warm up, runs cold, or overheats. It is common practice to replace both thermostats at the same time.

Before You Order

• 2011-2016 LML and LGH only: for 2001-2010 trucks, see the 2001-2010 Thermostat Kit. For 2017 and newer L5P trucks, see the L5P Thermostat Kit.

Related Parts

• Thermostat Housing Crossover Gaskets, Set of 2, 2001-2016
• WC Fab Thermostat Housing, LML Duramax

Frequently Asked Questions

How do I tell the front and rear thermostats apart?
The front thermostat is symmetrical. The rear thermostat has an offset design with built-in bleeder valves.

Should I replace both thermostats?
It is common practice to replace both at the same time, which is why this kit includes both.

For warranty information, see our Warranty Policy.