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GMC Thermostat

163 items

Upgrade your vehicle's thermostat with A-Premium's high-quality options. Choose reliability and durability for a smoother ride.

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Thermostat Housing Assembly with Thermostat for 2002-2009 GMC EnvoyThermostat Housing Assembly with Thermostat for 2002-2009 GMC Envoy
A-Premium®Part # APTHA0127
Thermostat Housing Assembly with Thermostat for 2002-2009 GMC Envoy
52 Reviews
CA$40.99
CA$45.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC Envoy: 2002 2003 2004 2005 2006 2007 2008 2009
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedCanada
Quantity1
ConditionNew
item #1012ZLS4
Note
This item comes with a Cover.
Show less
Engine Coolant Thermostat Housing Assembly for 1999-2003 GMC Sierra 1500
A-Premium®Part # APTHA0109
Engine Coolant Thermostat Housing Assembly for 1999-2003 GMC Sierra 1500
52 Reviews
CA$42.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC Sierra 1500: 1999 2000 2001 2002 2003
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedCanada
ColorNatural
ConditionNew
item #1012Y5HK
Note
Engine Coolant Thermostat Housing Assembly -- With Water Pump Casting No. 12562459, Includes 186 Fahrenheit Degree Thermostat.
Show less
Thermostat Housing Assembly for 2003 GMC Savana 2500
A-Premium®Part # APTHA0128
Thermostat Housing Assembly for 2003 GMC Savana 2500
52 Reviews
CA$43.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits 2003 GMC Savana 2500
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedCanada
Quantity1
MaterialAluminum
ConditionNew
item #10027STA
Show less
Engine Coolant Thermostat Housing Assembly for 1988-1995 GMC K2500
A-Premium®Part # APTHA0148
Engine Coolant Thermostat Housing Assembly for 1988-1995 GMC K2500
52 Reviews
CA$39.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedCanada
Quantity1
ConditionNew
item #1012ZUX9
Note
This item comes with Cover.
Show less
Thermostat Housing Assembly with Thermostat for 2004-2005 GMC Envoy XUV
A-Premium®Part # APTHA0127
Thermostat Housing Assembly with Thermostat for 2004-2005 GMC Envoy XUV
52 Reviews
CA$40.99
CA$45.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC Envoy XUV: 2004 2005
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedCanada
Quantity1
ConditionNew
item #1012ZGNN
Note
This item comes with a Cover.
Show less
Engine Coolant Thermostat Housing Assembly for 2001-2003 GMC Sierra 3500
A-Premium®Part # APTHA0109
Engine Coolant Thermostat Housing Assembly for 2001-2003 GMC Sierra 3500
52 Reviews
CA$42.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC Sierra 3500: 2001 2002 2003
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedCanada
ColorNatural
ConditionNew
item #1012Y5A6
Note
Engine Coolant Thermostat Housing Assembly -- With Water Pump Casting No. 12562459, Includes 186 Fahrenheit Degree Thermostat.
Show less
Thermostat Housing Assembly for 1999-2003 GMC Sierra 2500
A-Premium®Part # APTHA0128
Thermostat Housing Assembly for 1999-2003 GMC Sierra 2500
52 Reviews
CA$43.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedCanada
Quantity1
MaterialAluminum
ConditionNew
item #1012ZYRW
Show less
Engine Coolant Thermostat Housing Assembly for 1992-1995 GMC G2500
A-Premium®Part # APTHA0148
Engine Coolant Thermostat Housing Assembly for 1992-1995 GMC G2500
52 Reviews
CA$39.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC G2500: 1992 1993 1994 1995
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedCanada
Quantity1
ConditionNew
item #1012ZYPS
Note
This item comes with Cover.
Show less
Thermostat Housing for 2004-2006 GMC W3500 Forward
A-Premium®Part # APTHA0198
Thermostat Housing for 2004-2006 GMC W3500 Forward
52 Reviews
CA$39.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC W3500 Forward: 2004 2005 2006
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ColorNatural
ConditionNew
item #10152LCY
Show less
Engine Coolant Thermostat Housing Assembly for 2000-2003 GMC Yukon XL 2500
A-Premium®Part # APTHA0109
Engine Coolant Thermostat Housing Assembly for 2000-2003 GMC Yukon XL 2500
52 Reviews
CA$42.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC Yukon XL 2500: 2000 2001 2002 2003
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedCanada
ColorNatural
ConditionNew
item #1012Y756
Note
Engine Coolant Thermostat Housing Assembly -- With Water Pump Casting No. 12562459, Includes 186 Fahrenheit Degree Thermostat.
Show less
Thermostat Housing Assembly for 2003 GMC Envoy XL
A-Premium®Part # APTHA0128
Thermostat Housing Assembly for 2003 GMC Envoy XL
52 Reviews
CA$43.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits 2003 GMC Envoy XL
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedCanada
Quantity1
MaterialAluminum
ConditionNew
item #10027PCS
Show less
Engine Coolant Thermostat Housing Assembly for 1992-1995 GMC C2500 Suburban
A-Premium®Part # APTHA0148
Engine Coolant Thermostat Housing Assembly for 1992-1995 GMC C2500 Suburban
52 Reviews
CA$39.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedCanada
Quantity1
ConditionNew
item #1012ZUZD
Note
This item comes with Cover.
Show less
Thermostat Housing for 2003-2006 GMC Savana 2500
A-Premium®Part # APTHA0198
Thermostat Housing for 2003-2006 GMC Savana 2500
52 Reviews
CA$39.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC Savana 2500: 2003 2004 2005 2006
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ColorNatural
ConditionNew
item #10152GA8
Show less
Engine Coolant Thermostat Housing Assembly for 2000-2003 GMC Yukon XL 1500
A-Premium®Part # APTHA0109
Engine Coolant Thermostat Housing Assembly for 2000-2003 GMC Yukon XL 1500
52 Reviews
CA$42.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC Yukon XL 1500: 2000 2001 2002 2003
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedCanada
ColorNatural
ConditionNew
item #1012Y92R
Note
Engine Coolant Thermostat Housing Assembly -- With Water Pump Casting No. 12562459, Includes 186 Fahrenheit Degree Thermostat.
Show less
Thermostat Housing Assembly for 2003 GMC Savana 1500
A-Premium®Part # APTHA0128
Thermostat Housing Assembly for 2003 GMC Savana 1500
52 Reviews
CA$43.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits 2003 GMC Savana 1500
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedCanada
Quantity1
MaterialAluminum
ConditionNew
item #10027SY7
Show less
Engine Coolant Thermostat Housing Assembly for 1988-1995 GMC C1500
A-Premium®Part # APTHA0148
Engine Coolant Thermostat Housing Assembly for 1988-1995 GMC C1500
52 Reviews
CA$39.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC C1500: 1988 1989 1990 1991 1992 1993 1994 1995
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedCanada
Quantity1
ConditionNew
item #1012ZXKK
Note
This item comes with Cover.
Show less
Thermostat Housing for 2007 GMC Sierra 3500 Classic
A-Premium®Part # APTHA0198
Thermostat Housing for 2007 GMC Sierra 3500 Classic
52 Reviews
CA$39.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits 2007 GMC Sierra 3500 Classic
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ColorNatural
ConditionNew
item #10152EHD
Show less
Thermostat Housing Assembly for 2018-2021 GMC Savana 2500
A-Premium®Part # APTHA0312
Thermostat Housing Assembly for 2018-2021 GMC Savana 2500
52 Reviews
CA$59.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC Savana 2500: 2018 2019 2020 2021
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
MaterialPlastic
ConditionNew
item #1015W0QX
Show less
Thermostat Housing Assembly for 1999-2003 GMC Sierra 1500
A-Premium®Part # APTHA0128
Thermostat Housing Assembly for 1999-2003 GMC Sierra 1500
52 Reviews
CA$43.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC Sierra 1500: 1999 2000 2001 2002 2003
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedCanada
Quantity1
MaterialAluminum
ConditionNew
item #1012ZUNG
Show less
Engine Coolant Thermostat Housing Assembly for 2018-2021 GMC Terrain
A-Premium®Part # APTHA0036
Engine Coolant Thermostat Housing Assembly for 2018-2021 GMC Terrain
52 Reviews
CA$51.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC Terrain: 2018 2019 2020 2021
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedCanada
Quantity1
Part interchange
902-2089, 12651603, 12679095, 25201447
ConditionNew
item #1004T4W3
Show less
Page 2 of 9

What is an engine thermostat?

 While all engines can become too hot, if your thermostat isn't working correctly, your engine's well-being is at serious risk. The engine thermostat, often simply referred to as a thermostat, regulates the engine's operating temperature within an optimal range (typically around 195 to 220 degrees Fahrenheit).

How does a car thermostat work?

As a temperature-sensitive valve within the cooling system, a car thermostat responds to changes in coolant temperature. Understanding how it works by the following breakdown steps:

  • Closed position (cold start)

Initially closed to help the engine warm up quickly.

  • Heating up

The engine generates heat during operation.

  • Opening the thermostat

A temperature-sensitive element (usually wax) causes the thermostat to open gradually.

  • Coolant flow

When open, coolant flows from the engine to the radiator.

  • Maintaining optimal temperature

Adjusts coolant flow to maintain the ideal engine temperature.

  • Temperature regulation

Continuously adjusts to prevent overheating and ensure efficient operation.

Signs of a bad thermostat

  1. Overheating: The engine becomes excessively hot due to a stuck-closed thermostat.
  2. Low or fluctuating temperature: A thermostat stuck open results in a cooler engine, affecting fuel efficiency and heating.
  3. Temperature warning light: Illuminates to indicate engine overheating due to a faulty thermostat.
  4. Poor fuel efficiency: Stuck-open thermostat reduces fuel efficiency as the engine operates less efficiently at lower temperatures.
  5. Inadequate cabin heating: Insufficient cabin heating in cold weather with a thermostat that's stuck open.
  6. Coolant leaks: Gasket or sealing issues can lead to coolant leaks.
  7. Rapid temperature fluctuations: The gauge shows rapid swings between hot and cold.
  8. Engine running hot at idle: Higher engine temperature during idle or in traffic due to restricted coolant flow.
  9. Slow or inconsistent warm-up: Longer-than-normal warm-up times, even in moderate weather.
  10. Inconsistent heater operation: This affects the performance of the vehicle's heater, causing inconsistent or inadequate heating in cold weather.

Related Blogs

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Learn why coolant boils or bubbles after you turn the engine off, how heat soak affects the cooling system, and how to diagnose leaks, trapped air, cap, thermostat, fan, water pump, or head gasket problems.

Jul 29, 2026