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GMC Thermostat

227 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 for 2003 GMC Savana 1500Thermostat Housing Assembly for 2003 GMC Savana 1500
A-Premium®Part # APTHA0129
Thermostat Housing Assembly for 2003 GMC Savana 1500
4.798 Reviews
$23.99
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 LocatedUnited States
Quantity1
MaterialAluminum
ConditionNew
item #10027QUD
Show less
Engine Coolant Thermostat for 1999-2009 GMC C6500 Topkick
A-Premium®Part # APTHE082
Engine Coolant Thermostat for 1999-2009 GMC C6500 Topkick
4.798 Reviews
$20.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC C6500 Topkick: 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #1014H0Z3
Note
【Note-1】 Start to Open Temperature: 91℃.
【Note-2】 This item comes with seal.
Show less
Thermostat Housing Assembly for 2003 GMC Savana 1500
A-Premium®Part # APTHA0128
Thermostat Housing Assembly for 2003 GMC Savana 1500
4.798 Reviews
$22.99
Low stock: Only 3 left
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 LocatedUnited States
Quantity1
MaterialAluminum
ConditionNew
item #10027SY7
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
4.798 Reviews
$18.99
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 LocatedUnited States
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 1999-2003 GMC Sierra 1500
A-Premium®Part # APTHA0129
Thermostat Housing Assembly for 1999-2003 GMC Sierra 1500
4.798 Reviews
$23.99
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 LocatedUnited States
Quantity1
MaterialAluminum
ConditionNew
item #1012ZUPK
Show less
Engine Coolant Thermostat for 2003-2009 GMC C5500 Topkick
A-Premium®Part # APTHE082
Engine Coolant Thermostat for 2003-2009 GMC C5500 Topkick
4.798 Reviews
$20.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC C5500 Topkick: 2003 2004 2005 2006 2007 2008 2009
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #1014H08Q
Note
【Note-1】 Start to Open Temperature: 91℃.
【Note-2】 This item comes with seal.
Show less
Thermostat Housing Assembly for 1999-2003 GMC Sierra 1500
A-Premium®Part # APTHA0128
Thermostat Housing Assembly for 1999-2003 GMC Sierra 1500
4.798 Reviews
$22.99
Low stock: Only 3 left
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 LocatedUnited States
Quantity1
MaterialAluminum
ConditionNew
item #1012ZUNG
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
4.798 Reviews
$18.99
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 LocatedUnited States
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 2001-2003 GMC Sierra 2500 HD
A-Premium®Part # APTHA0129
Thermostat Housing Assembly for 2001-2003 GMC Sierra 2500 HD
4.798 Reviews
$23.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC Sierra 2500 HD: 2001 2002 2003
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
MaterialAluminum
ConditionNew
item #1012ZWGD
Show less
Engine Coolant Thermostat for 2007 GMC Sierra 3500 Classic
A-Premium®Part # APTHE082
Engine Coolant Thermostat for 2007 GMC Sierra 3500 Classic
4.798 Reviews
$20.99
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
ConditionNew
item #1014GY9G
Note
【Note-1】 Start to Open Temperature: 91℃.
【Note-2】 This item comes with seal.
Show less
Thermostat Housing Assembly for 2001-2003 GMC Sierra 2500 HD
A-Premium®Part # APTHA0128
Thermostat Housing Assembly for 2001-2003 GMC Sierra 2500 HD
4.798 Reviews
$22.99
Low stock: Only 3 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC Sierra 2500 HD: 2001 2002 2003
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
MaterialAluminum
ConditionNew
item #1012ZZCZ
Show less
Engine Coolant Thermostat Housing Assembly for 2000-2003 GMC Yukon
A-Premium®Part # APTHA0109
Engine Coolant Thermostat Housing Assembly for 2000-2003 GMC Yukon
4.798 Reviews
$18.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC Yukon: 2000 2001 2002 2003
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
ColorNatural
ConditionNew
item #1012Y5P4
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 3500
A-Premium®Part # APTHA0129
Thermostat Housing Assembly for 2003 GMC Savana 3500
4.798 Reviews
$23.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits 2003 GMC Savana 3500
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
MaterialAluminum
ConditionNew
item #10027Q5X
Show less
Engine Coolant Thermostat for 2003-2009 GMC C8500 Topkick
A-Premium®Part # APTHE082
Engine Coolant Thermostat for 2003-2009 GMC C8500 Topkick
4.798 Reviews
$20.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC C8500 Topkick: 2003 2004 2005 2006 2007 2008 2009
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #1014H22C
Note
【Note-1】 Start to Open Temperature: 91℃.
【Note-2】 This item comes with seal.
Show less
Thermostat Housing Assembly for 2003 GMC Savana 3500
A-Premium®Part # APTHA0128
Thermostat Housing Assembly for 2003 GMC Savana 3500
4.798 Reviews
$22.99
Low stock: Only 3 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits 2003 GMC Savana 3500
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
MaterialAluminum
ConditionNew
item #10027SWQ
Show less
A-Premium APTHE030 2007 GMC W3500 Forward Engine Coolant Thermostat
A-Premium®Part # APTHE030
A-Premium APTHE030 2007 GMC W3500 Forward Engine Coolant Thermostat
4.798 Reviews
$19.99
Low stock: Only 5 left
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 LocatedUnited States
Quantity1
MaterialMetal and Rubber
ConditionNew
item #1012NQRR
Show less
Thermostat Housing Assembly for 2001-2003 GMC Sierra 1500 HD
A-Premium®Part # APTHA0129
Thermostat Housing Assembly for 2001-2003 GMC Sierra 1500 HD
4.798 Reviews
$23.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC Sierra 1500 HD: 2001 2002 2003
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
MaterialAluminum
ConditionNew
item #1012ZWH9
Show less
Engine Coolant Thermostat for 1999-2009 GMC C7500 Topkick
A-Premium®Part # APTHE082
Engine Coolant Thermostat for 1999-2009 GMC C7500 Topkick
4.798 Reviews
$20.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC C7500 Topkick: 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #1014H4KL
Note
【Note-1】 Start to Open Temperature: 91℃.
【Note-2】 This item comes with seal.
Show less
Thermostat Housing Assembly for 2001-2003 GMC Sierra 1500 HD
A-Premium®Part # APTHA0128
Thermostat Housing Assembly for 2001-2003 GMC Sierra 1500 HD
4.798 Reviews
$22.99
Low stock: Only 3 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC Sierra 1500 HD: 2001 2002 2003
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
MaterialAluminum
ConditionNew
item #1012ZYSY
Show less
A-Premium APTHE030 2007 GMC C8500 Topkick Engine Coolant Thermostat
A-Premium®Part # APTHE030
A-Premium APTHE030 2007 GMC C8500 Topkick Engine Coolant Thermostat
4.798 Reviews
$19.99
Low stock: Only 5 left
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 LocatedUnited States
Quantity1
MaterialMetal and Rubber
ConditionNew
item #1012NK13
Show less
Page 3 of 12

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.

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Jul 29, 2026