Save Up to 15% on Back to School Auto Parts
24/7 Customer service
USD
Add your vehicle
Address
Login
Cart
Item
$0.00
A-Premium Back to School Car Deals Up to 15% OFFA-Premium Back to School Car Deals Up to 15% OFF
Add your vehicle to ensure fitment/Choose a yearRequired Fields
Select a different vehicle
Make/Model
VIN
Save

Jaguar XJ8 Thermostat

6 items

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

  • All filters
  • Sort By
  • Year
  • Price
  • Brand
  • Color
  • Warranty
Engine Coolant Thermostat Housing Assy for Jaguar S-Type 2006-2008 XF XJ8 XK XKREngine Coolant Thermostat Housing Assy for Jaguar S-Type 2006-2008 XF XJ8 XK XKR
A-Premium®Part # APTHA0070
Engine Coolant Thermostat Housing Assy for Jaguar S-Type 2006-2008 XF XJ8 XK XKR
4.683 Reviews
$68.99
Edit ZIP code
2-year warranty
90 days free return
Fits 2006 - 2008 Jaguar S-Type, 2006 - 2006 Jaguar S-Type, 2006 - 2009 Jaguar Vanden Plas, 2010 - 2010 Jaguar XF, 2009 - 2009 Jaguar XF, 2006 - 2009 Jaguar XJ8, 2007 - 2009 Jaguar XK
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Jaguar XJ8
Item LocatedUnited States
Quantity1
ColorBlack
item #1000GWHD
Note
It fits the model with V8 4.2L Engine Only.
Show less
Beck/Arnley 143-0885 Engine Coolant Thermostat Housing Assembly
Beck/ArnleyPart # 143-0885
Beck/Arnley 143-0885 Engine Coolant Thermostat Housing Assembly
51 Reviews
$59.99
Edit ZIP code
3-year warranty
90 days free return
Fits 2003-2006 Jaguar S-Type, 2003-2008 Jaguar S-Type, 2004-2005 Jaguar Vanden Plas, 2004-2005 Jaguar XJ8, 2004-2005 Jaguar XJR, 2006-2006 Jaguar S-Type
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Jaguar XJ8
Item LocatedUnited States
Quantity1
Part interchange
143-0885
item #1000X7PD
Show less
ÜRO Parts AJ811793 Engine Coolant Thermostat / Water Inlet Assembly
ÜRO PartsPart # AJ811793
ÜRO Parts AJ811793 Engine Coolant Thermostat / Water Inlet Assembly
52 Reviews
$159.99
Edit ZIP code
3-year warranty
90 days free return
Fits 2003-2003 Jaguar S-Type, 2003-2003 Jaguar S-Type, 2003-2003 Jaguar S-Type, 2004-2006 Jaguar S-Type, 2004-2008 Jaguar S-Type, 2004-2008 Jaguar S-Type, 2004-2009 Jaguar Vanden Plas, 2004-2009 Jaguar XJ8, 2006-2006 Jaguar S-Type, 2007-2009 Jaguar XK, 2009-2010 Jaguar XF
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Jaguar XJ8
Item LocatedUnited States
Quantity1
ColorBlack
Part interchange
AJ811793, AJ810214, AJ8946/5, AJ811793, URO-015312
item #1000ZRUR
Show less
Vemo V15-99-1990 Engine Coolant Thermostat
VemoPart # V15-99-1990
Vemo V15-99-1990 Engine Coolant Thermostat
57 Reviews
$32.99
Edit ZIP code
3-year warranty
90 days free return
Fits 1990-1994 Audi V8 Quattro, 1992-1994 Audi 100, 1992-1994 Audi 100 Quattro, 1993-1995 Audi 90, 1993-1995 Audi 90 Quattro, 1994-1998 Audi Cabriolet, 1995-1998 Audi A6, 1995-1998 Audi A6 Quattro, 1996-1996 Audi A4, 1996-1996 Audi A4 Quattro, 1997-1998 Audi A4, 1997-1998 Audi A4 Quattro, 1997-1999 Audi A8, 1997-1999 Audi A8 Quattro, 1999-1999 Audi A4, 1999-1999 Audi A4 Quattro, 1999-1999 Audi A6, 1999-1999 Audi A6 Quattro, 2000-2002 Audi S4, 2000-2004 Audi A6 Quattro
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Jaguar XJ8
Item LocatedUnited States
Quantity1
Part interchange
V15-99-1990, TX3087D, 78410S, 5305987, 30487, 067121113, 078121113D, 25121113F, 
...View more
item #1001QPCT
Show less
Beck/Arnley 143-0792 Engine Coolant Thermostat
Beck/ArnleyPart # 143-0792
Beck/Arnley 143-0792 Engine Coolant Thermostat
51 Reviews
$41.99
Edit ZIP code
3-year warranty
90 days free return
Fits 1997-2002 Jaguar XK8, 1998-1998 Jaguar Vanden Plas, 1998-2003 Jaguar XJ8
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Jaguar XJ8
Item LocatedUnited States
QuantityOne Set
Part interchange
143-0792
item #1000XH32
Show less
Beck/Arnley 143-0890 Engine Coolant Thermostat Housing Assembly
Beck/ArnleyPart # 143-0890
Beck/Arnley 143-0890 Engine Coolant Thermostat Housing Assembly
51 Reviews
$78.99
Edit ZIP code
3-year warranty
90 days free return
Fits 1997-2002 Jaguar XK8, 1998-2003 Jaguar XJ8, 1998-2003 Jaguar XJR, 1999-2003 Jaguar Vanden Plas, 2000-2002 Jaguar S-Type, 2000-2006 Jaguar XKR, 2005-2005 Jaguar Super V8
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Jaguar XJ8
Item LocatedUnited States
QuantityOne Set
Part interchange
143-0890
item #1000XA0Z
Show less

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

Why Does Coolant Boil After You Turn the Engine Off?

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