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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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Engine Coolant Thermostat for 1991-1997 GMC P3500Engine Coolant Thermostat for 1991-1997 GMC P3500
A-Premium®Part # APTHE078
Engine Coolant Thermostat for 1991-1997 GMC P3500
4.798 Reviews
$20.99
Low stock: Only 4 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC P3500: 1991 1992 1993 1994 1995 1996 1997
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #1014GTK9
Note
Start to Open Temperature: 91℃.
Show less
Heavy Duty Thermostat for 1999-2010 GMC W4500 Forward
A-Premium®Part # APTHE085
Heavy Duty Thermostat for 1999-2010 GMC W4500 Forward
4.798 Reviews
$23.99
Low stock: Only 2 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC W4500 Forward: 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #10177KTE
Note
Start to Open Temperature: 82℃.
Show less
Engine Coolant Thermostat for 1982-1987 1989 GMC S15
A-Premium®Part # APTHE091
Engine Coolant Thermostat for 1982-1987 1989 GMC S15
4.798 Reviews
$16.99
Low stock: Only 5 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC S15: 1982 1983 1984 1985 1986 1987 1989
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #10188N3X
Note
Start to Open Temperature: 92℃.
Show less
Engine Coolant Thermostat for 1983-1989 GMC S15 Jimmy
A-Premium®Part # APTHE091
Engine Coolant Thermostat for 1983-1989 GMC S15 Jimmy
4.798 Reviews
$16.99
Low stock: Only 5 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC S15 Jimmy: 1983 1984 1985 1986 1987 1988 1989
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #10188KAZ
Note
Start to Open Temperature: 92℃.
Show less
Engine Coolant Thermostat for 1991 GMC V3500
A-Premium®Part # APTHE078
Engine Coolant Thermostat for 1991 GMC V3500
4.798 Reviews
$20.99
Low stock: Only 4 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits 1991 GMC V3500
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #1014GRV1
Note
Start to Open Temperature: 91℃.
Show less
Engine Coolant Thermostat for 1992-1995 GMC K2500 Suburban
A-Premium®Part # APTHE078
Engine Coolant Thermostat for 1992-1995 GMC K2500 Suburban
4.798 Reviews
$20.99
Low stock: Only 4 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC K2500 Suburban: 1992 1993 1994 1995
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #1014GTEK
Note
Start to Open Temperature: 91℃.
Show less
Engine Coolant Thermostat for 1991-1995 GMC C3500
A-Premium®Part # APTHE078
Engine Coolant Thermostat for 1991-1995 GMC C3500
4.798 Reviews
$20.99
Low stock: Only 4 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC C3500: 1991 1992 1993 1994 1995
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #1014GTEW
Note
Start to Open Temperature: 91℃.
Show less
Heavy Duty Thermostat for 1999-2008 GMC W3500 Forward
A-Premium®Part # APTHE085
Heavy Duty Thermostat for 1999-2008 GMC W3500 Forward
4.798 Reviews
$23.99
Low stock: Only 2 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC W3500 Forward: 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #10177L93
Note
Start to Open Temperature: 82℃.
Show less
Engine Coolant Thermostat for 1991-1995 GMC K3500
A-Premium®Part # APTHE078
Engine Coolant Thermostat for 1991-1995 GMC K3500
4.798 Reviews
$20.99
Low stock: Only 4 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC K3500: 1991 1992 1993 1994 1995
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #1014GPAL
Note
Start to Open Temperature: 91℃.
Show less
Heavy Duty Thermostat for 2004-2009 GMC W5500HD Forward
A-Premium®Part # APTHE085
Heavy Duty Thermostat for 2004-2009 GMC W5500HD Forward
4.798 Reviews
$23.99
Low stock: Only 2 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC W5500HD Forward: 2004 2005 2006 2007 2008 2009
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #10177D7P
Note
Start to Open Temperature: 82℃.
Show less
Engine Coolant Thermostat for 1988 1990 GMC S15
A-Premium®Part # APTHE078
Engine Coolant Thermostat for 1988 1990 GMC S15
4.798 Reviews
$20.99
Low stock: Only 4 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC S15: 1988 1990
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #1014GSAK
Note
Start to Open Temperature: 91℃.
Show less
Engine Coolant Thermostat for 1991 GMC R3500
A-Premium®Part # APTHE078
Engine Coolant Thermostat for 1991 GMC R3500
4.798 Reviews
$20.99
Low stock: Only 4 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits 1991 GMC R3500
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #1014GREX
Note
Start to Open Temperature: 91℃.
Show less
Engine Coolant Thermostat for 1991-2003 GMC Sonoma
A-Premium®Part # APTHE078
Engine Coolant Thermostat for 1991-2003 GMC Sonoma
4.798 Reviews
$20.99
Low stock: Only 4 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC Sonoma: 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #1014GQ28
Note
Start to Open Temperature: 91℃.
Show less
Engine Coolant Thermostat for 1992-1995 GMC Jimmy
A-Premium®Part # APTHE078
Engine Coolant Thermostat for 1992-1995 GMC Jimmy
4.798 Reviews
$20.99
Low stock: Only 4 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC Jimmy: 1992 1993 1994 1995
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #1014GSU9
Note
Start to Open Temperature: 91℃.
Show less
Engine Coolant Thermostat for 1992-1995 GMC Safari
A-Premium®Part # APTHE078
Engine Coolant Thermostat for 1992-1995 GMC Safari
4.798 Reviews
$20.99
Low stock: Only 4 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC Safari: 1992 1993 1994 1995
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #1014GPPR
Note
Start to Open Temperature: 91℃.
Show less
Engine Coolant Thermostat for 1991-1996 GMC G3500
A-Premium®Part # APTHE078
Engine Coolant Thermostat for 1991-1996 GMC G3500
4.798 Reviews
$20.99
Low stock: Only 4 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC G3500: 1991 1992 1993 1994 1995 1996
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #1014GRZW
Note
Start to Open Temperature: 91℃.
Show less
Engine Coolant Thermostat for 1992-1995 GMC C2500 Suburban
A-Premium®Part # APTHE078
Engine Coolant Thermostat for 1992-1995 GMC C2500 Suburban
4.798 Reviews
$20.99
Low stock: Only 4 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC C2500 Suburban: 1992 1993 1994 1995
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #1014GU8T
Note
Start to Open Temperature: 91℃.
Show less
Engine Coolant Thermostat for 1991-1995 GMC C3500HD
A-Premium®Part # APTHE078
Engine Coolant Thermostat for 1991-1995 GMC C3500HD
4.798 Reviews
$20.99
Low stock: Only 4 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC C3500HD: 1991 1992 1993 1994 1995
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #1014GQ16
Note
Start to Open Temperature: 91℃.
Show less
Engine Coolant Thermostat for 1991-1995 GMC C2500
A-Premium®Part # APTHE078
Engine Coolant Thermostat for 1991-1995 GMC C2500
4.798 Reviews
$20.99
Low stock: Only 4 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC C2500: 1991 1992 1993 1994 1995
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #1014GQ7S
Note
Start to Open Temperature: 91℃.
Show less
Heavy Duty Thermostat for 1999-2010 GMC W5500 Forward
A-Premium®Part # APTHE085
Heavy Duty Thermostat for 1999-2010 GMC W5500 Forward
4.798 Reviews
$23.99
Low stock: Only 2 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits GMC W5500 Forward: 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: GMC
Item LocatedUnited States
Quantity1
ConditionNew
item #10177KNG
Note
Start to Open Temperature: 82℃.
Show less
Page 11 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