Duramax LLY / LBZ Thermostat 2004-2007 Wehrli WCF100420-RED

Wehrli thermostat for the Duramax LLY / LBZ (2004-2007). Listed for one application: Duramax LLY / LBZ engines, 2004-2007, in Chevrolet, GMC applications. Confirm your engine code and year against this listing before ordering.

What it does

The thermostat controls when coolant flows to the radiator and sets operating temperature. Stuck closed it overheats the engine; stuck open it never warms up, hurting mileage and setting a P0128. A new thermostat at the correct rating restores stable temperature.

Fits

• Chevrolet vehicles with the Duramax LLY / LBZ engine, 2004-2007
• GMC vehicles with the Duramax LLY / LBZ engine, 2004-2007

Fixes

• P0128 coolant temperature below regulating range
• overheating with a cool radiator
• a slow warm-up and poor heater output

What's included

• the thermostat (and housing / seal where the listing says so)

Specifications

• Brand: Wehrli
• Part number: WCF100420-RED
• Shipping weight: 6.3 lb
• Condition: new
• Product type: Thermostat

Cross-reference

Replaces or interchanges with Wehrli WCF100420-RED for the Duramax LLY / LBZ. Check the part number stamped on your original before ordering.

Free shipping on orders of $70 or more; everything else ships with calculated shipping at the part's real weight. Questions on fitment? Ask a tech before you buy.