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Mercury Thermostat

86 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 Housing Assembly for 2002-2010 Mercury MountaineerEngine Coolant Thermostat Housing Assembly for 2002-2010 Mercury Mountaineer
A-Premium®Part # APTHA0030
Engine Coolant Thermostat Housing Assembly for 2002-2010 Mercury Mountaineer
4.797 Reviews
$26.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits Mercury Mountaineer: 2002 2003 2004 2005 2006 2007 2008 2009 2010
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury
Item LocatedUnited States
ColorBlack
ConditionNew
item #10047X38
Note
This part comes with a temperature sensor and it fits the vehicles with engine V6 4.0L only.
Show less
Engine Coolant Thermostat for 2006-2011 Mercury Mariner
A-Premium®Part # APTHA0326
Engine Coolant Thermostat for 2006-2011 Mercury Mariner
4.797 Reviews
$26.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits Mercury Mariner: 2006 2007 2008 2009 2010 2011
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury
Item LocatedUnited States
Quantity1
ConditionNew
item #10177KY3
Note
Start to Open Temperature: 90℃.
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Engine Coolant Thermostat Housing Assembly for 2006-2011 Mercury Milan
A-Premium®Part # APTHA0082
Engine Coolant Thermostat Housing Assembly for 2006-2011 Mercury Milan
4.797 Reviews
$23.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits Mercury Milan: 2006 2007 2008 2009 2010 2011
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury
Item LocatedUnited States
ColorBlack
ConditionNew
item #1012Y5WH
Note
Engine Coolant Thermostat Housing Assembly -- Cover, Includes Thermostat.
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Engine Coolant Thermostat Housing Assembly for 1999-2000 Mercury Mystique
A-Premium®Part # APTHA0007
Engine Coolant Thermostat Housing Assembly for 1999-2000 Mercury Mystique
4.797 Reviews
$33.99
Low stock: Only 3 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits Mercury Mystique: 1999 2000
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury
Item LocatedUnited States
Quantity1
ColorBlack
ConditionNew
item #1003D0AE
Show less
Engine Coolant Thermostat Housing Assembly for 2005-2008 Mercury Mariner
A-Premium®Part # APTHA0034
Engine Coolant Thermostat Housing Assembly for 2005-2008 Mercury Mariner
4.797 Reviews
$30.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits Mercury Mariner: 2005 2006 2007 2008
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury
Item LocatedUnited States
ColorBlack
ConditionNew
item #10047THZ
Note
This part comes with a cover and thermostat.
Show less
Engine Coolant Thermostat for 2006-2011 Mercury Milan
A-Premium®Part # APTHA0326
Engine Coolant Thermostat for 2006-2011 Mercury Milan
4.797 Reviews
$26.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits Mercury Milan: 2006 2007 2008 2009 2010 2011
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury
Item LocatedUnited States
Quantity1
ConditionNew
item #10177DYZ
Note
Start to Open Temperature: 90℃.
Show less
Engine Coolant Thermostat Housing Assembly for 2006-2011 Mercury Mariner
A-Premium®Part # APTHA0082
Engine Coolant Thermostat Housing Assembly for 2006-2011 Mercury Mariner
4.797 Reviews
$23.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits Mercury Mariner: 2006 2007 2008 2009 2010 2011
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury
Item LocatedUnited States
ColorBlack
ConditionNew
item #1012Y9AE
Note
Engine Coolant Thermostat Housing Assembly -- Cover, Includes Thermostat.
Show less
Engine Coolant Thermostat Housing Assembly for 1999-2002 Mercury Cougar
A-Premium®Part # APTHA0007
Engine Coolant Thermostat Housing Assembly for 1999-2002 Mercury Cougar
4.797 Reviews
$33.99
Low stock: Only 3 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits Mercury Cougar: 1999 2000 2001 2002
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury
Item LocatedUnited States
Quantity1
ColorBlack
ConditionNew
item #1003CY3E
Show less
Engine Coolant Thermostat for 1991-1994 Mercury Capri
A-Premium®Part # APTHE081
Engine Coolant Thermostat for 1991-1994 Mercury Capri
4.797 Reviews
$20.99
Low stock: Only 5 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits Mercury Capri: 1991 1992 1993 1994
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury
Item LocatedUnited States
Quantity1
MaterialMetal and Rubber
ConditionNew
item #1012NL65
Show less
Engine Coolant Thermostat for 2002-2010 Mercury Mountaineer
A-Premium®Part # APTHE036
Engine Coolant Thermostat for 2002-2010 Mercury Mountaineer
4.797 Reviews
$25.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits Mercury Mountaineer: 2002 2003 2004 2005 2006 2007 2008 2009 2010
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury
Item LocatedUnited States
Quantity1
MaterialMetal, Rubber
ConditionNew
item #1012NPPV
Show less
Engine Coolant Thermostat for 2002-2010 Mercury Mountaineer
A-Premium®Part # APTHE035
Engine Coolant Thermostat for 2002-2010 Mercury Mountaineer
4.797 Reviews
$22.99
Low stock: Only 5 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits Mercury Mountaineer: 2002 2003 2004 2005 2006 2007 2008 2009 2010
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury
Item LocatedUnited States
Quantity1
ConditionNew
item #1014GSD7
Note
Start to Open Temperature: 82℃.
Show less
Engine Coolant Thermostat for 2002-2010 Mercury Mountaineer
A-Premium®Part # APTHE004
Engine Coolant Thermostat for 2002-2010 Mercury Mountaineer
4.797 Reviews
$31.99
Low stock: Only 5 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits Mercury Mountaineer: 2002 2003 2004 2005 2006 2007 2008 2009 2010
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury
Item LocatedUnited States
Quantity1
MaterialMetal and Rubber
ConditionNew
item #1012NE2W
Show less
Engine Coolant Thermostat for 1987-1996 Mercury Tracer
A-Premium®Part # APTHE081
Engine Coolant Thermostat for 1987-1996 Mercury Tracer
4.797 Reviews
$20.99
Low stock: Only 5 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits Mercury Tracer: 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury
Item LocatedUnited States
Quantity1
MaterialMetal and Rubber
ConditionNew
item #1012NLP7
Show less
Engine Coolant Thermostat for 1992-2011 Mercury Grand Marquis
A-Premium®Part # APTHE036
Engine Coolant Thermostat for 1992-2011 Mercury Grand Marquis
4.797 Reviews
$25.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury
Item LocatedUnited States
Quantity1
MaterialMetal, Rubber
ConditionNew
item #1012NPHR
Show less
Engine Coolant Thermostat for 1992-2011 Mercury Grand Marquis
A-Premium®Part # APTHE035
Engine Coolant Thermostat for 1992-2011 Mercury Grand Marquis
4.797 Reviews
$22.99
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: Mercury
Item LocatedUnited States
Quantity1
ConditionNew
item #1014GPNQ
Note
Start to Open Temperature: 82℃.
Show less
Engine Coolant Thermostat for 1992-2011 Mercury Grand Marquis
A-Premium®Part # APTHE004
Engine Coolant Thermostat for 1992-2011 Mercury Grand Marquis
4.797 Reviews
$31.99
Low stock: Only 5 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits Mercury Grand Marquis: 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury
Item LocatedUnited States
Quantity1
MaterialMetal and Rubber
ConditionNew
item #1012NDHE
Show less
Engine Coolant Thermostat for 2002-2010 Mercury Mountaineer
A-Premium®Part # APTHE003
Engine Coolant Thermostat for 2002-2010 Mercury Mountaineer
4.797 Reviews
$20.99
Low stock: Only 2 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits Mercury Mountaineer: 2002 2003 2004 2005 2006 2007 2008 2009 2010
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury
Item LocatedUnited States
Quantity1
MaterialMetal and Rubber
ConditionNew
item #1012N8EL
Show less
Engine Coolant Thermostat for 1994-1997 Mercury Cougar
A-Premium®Part # APTHE036
Engine Coolant Thermostat for 1994-1997 Mercury Cougar
4.797 Reviews
$25.99
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury
Item LocatedUnited States
Quantity1
MaterialMetal, Rubber
ConditionNew
item #1012NPSK
Show less
Engine Coolant Thermostat for 1994-1997 Mercury Cougar
A-Premium®Part # APTHE035
Engine Coolant Thermostat for 1994-1997 Mercury Cougar
4.797 Reviews
$22.99
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: Mercury
Item LocatedUnited States
Quantity1
ConditionNew
item #1014GS9G
Note
Start to Open Temperature: 82℃.
Show less
Engine Coolant Thermostat for 1994-1997 Mercury Cougar
A-Premium®Part # APTHE004
Engine Coolant Thermostat for 1994-1997 Mercury Cougar
4.797 Reviews
$31.99
Low stock: Only 5 left
Enter ZIP codeFree standard shipping
2-year warranty
90 days free return
Fits Mercury Cougar: 1994 1995 1996 1997
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury
Item LocatedUnited States
Quantity1
MaterialMetal and Rubber
ConditionNew
item #1012NE10
Show less
Page 1 of 5

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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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