First, make sure the engine is cold. Then, drain the coolant completely. Next, go to the thermostat housing following the large radiator hose attached to it. Then, with a set of slip joint pliers, unbolt the spring clamps on the hose. Twist the hose to remove it from the housing. Remove the three bolts which secure the thermostat cover to the housing. (1) Remove the thermostat cover from the housing. 85: Removing Thermostat Cover Courtesy of JAGUAR CARS, INC. Remove the thermostat from the housing. Remove the thermostat from the housing. (1) Remove (and discard) the seal from the thermostat. (2) Fit a new seal to the thermostat. Thermostat Housing 4.0 XK8. The 2 front bolts were easy access with an 8-mm socket and an extension. The 2 rear bolts are a different story. Access to the 2 bolts would not be so bad if the manifold was removed. I was not ready to remove the manifold so I bent the 8-mm open end wrench and began turning.

1. 1998 Jaguar Xj8 Problems

Service

What is an engine cooling system thermostat and how does it work?

The car's engine cooling system thermostat is a small valve within a cooling system passageway that opens and closes in response to the temperature of the circulating engine coolant. When your car is first started and the coolant is cold, the valve in the thermostat will be in the closed position, circulating the coolant flow only within the engine instead of flowing to the radiator, which allows the engine to warm up fast, promoting fuel efficiency, low emissions, and reduced engine deposits. Once the engine coolant reaches the design temperature, usually around 195 degrees, the valve will open and close as you drive in order to maintain a coolant temperature typically between 195 to 225 degrees Fahrenheit.

When to consider replacing the engine cooling system thermostat:

• Engine overheats. A thermostat with the valve stuck closed is a common cause of engine overheating. However, since there are other causes of overheating, a mechanic will thoroughly inspect the cooling system prior to condemning the thermostat. Since it is usually not known how badly the engine overheated, the mechanic will also try to determine if there is evidence that the cylinder head gasket was blown. If so, it would be repaired prior to replacing the thermostat.
• Temperature gauge reads too low or too high. Thermostats can get sticky, causing the engine temperature to stray from the optimal range. Your dash-mounted temperature gauge will notify you of this malfunction.
• Cooling system repairs. All thermostats eventually fail. Therefore, if the cooling system is already open for major repairs, such as water pump or radiator replacement, it is recommended to install a new thermostat simply as insurance against future breakdown.

How do mechanics replace the engine cooling system thermostat?

• Once the engine is completely cold, the radiator cap is loosened and enough coolant is drained from the radiator so the coolant level is below the thermostat housing.
• The thermostat housing is removed and the thermostat and gasket are extracted. Note that some cars have more than one cooling system thermostat and both might need replacement.
• All mounting surfaces on the thermostat housing are cleaned of old gasket material. A new gasket is applied and the thermostat is re-installed in the correct orientation and with the temperature sensing cylinder facing downward towards the engine.
• The thermostat housing bolts are tightened to original equipment manufacturer (OEM) specifications using a calibrated inch-pound torque wrench.
• The cooling system is refilled with the appropriate coolant type and the system is fully bled of all air.
• The car engine is run until the normal operating temperature is reached, and while taking precautions with the hot coolant, the coolant level is rechecked while confirming there is flow through the radiator — either visually or with an infrared temperature gun. This will confirm the thermostat is open. Finally, the engine is checked for leaks.

Is it safe to drive with an engine cooling system thermostat problem?

No. If it has been determined that there is a thermostat problem, it should be repaired right away. Failure to do so can cause substantial and costly damage to the engine.

When replacing the engine cooling system thermostat keep in mind:

• Engine overheating due to causes other than a faulty thermostat, will themselves damage a thermostat. Therefore, always replace the thermostat if the engine overheats, even if the thermostat was not the initial cause of the overheating.
  
• The thermostat should be replaced anytime you have major work done on the coolant system. It is convenient and costs little during such repairs and insurance against future breakdown.
• OEM thermostats are the best ones to use and you can request your mechanic to install only the OEM thermostat. Dealer supplied, OEM thermostats are sometimes more costly but are generally higher quality and specifically engineered for your car.

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How do you replace rear bumper jaguar 2001 xj8?

Try http://www.skjagtech.co.uk/support-pages/x30x/x300-x308-support-and-help-pages.html

Can a 2001 jaguar xj8 uses a synthetic oil blend?

Yes, unless Jaguar recommends you only use full synthetic.

What is the bolt pattern for a Jaguar XJ6 xj8?

I have a Jaguar XJ8 1998. the bolt pattern is 5X120

Where can you purchase a Jaguar XJ8?

You can purchase a Jaguar XJ8 at a local Jaguar dealership, or you can find available Jaguar XJ8s on the sites Auto Trader or Ebay Motors and purchase from the sellers.

How do you replace the timing chain on a Jaguar XJ8?

very carefully lol here is the link http://jeg.serverhouse.com/Jag_docs

How do you replace the door check on a jaguar xj8?

Hello, Did you ever get an answer, either from this or any other site? Bernie Day

Is xj8 the fastest Jaguar?

the Jaguar XJ220 claims a top speed of 217 mph. The XJ8 manages 150 mph

What does it mean when your transmission high temp jaguar 1999 xj8?

what does it mean when the hi transmission tempture light come on in a 1999 jaguar xj8

How do you replace a Jaguar XJ8 ECU?

Very easy to replace, but you have to match numbers under hood by engine bay, then when you replace it, you have to get it programmed at dealership or it still wont work! but replacing it is the easy part. Good luck!

Where is your battery located in 2002 jaguar?

On the 2001 XJ8 it is in the right side of the trunk under the false trunk floor. I suspect that the 2002 model is the same.

What would cause all of your coolant in your 2001 jaguar xj8 to leak out?

head gasket lets compession push coolant ont into over flow

Where is the fuel pump located on a 2001 jaguar xj8?

the fuel pump is located in the fuel cell. the sending unit for the gage & the fuel pump are on the same bracket.

How do you replace the brake light in a 1998 jaguar xj8?

Remove rear light unit cover in trunk. Turn bulb holder fastener 90 degrees counter clockwise and remove. Replace faulty bulb.

How do you access the battery of 2001 jaguar xj8?

Remove the floor pan in the boot then lift the panel on the right. The battery is situated underneath along with fuses & relay switches.

How do you get owners manual for 1999 jaguar xj8?

I need a repair manual for a 1999 jaguar van da plaz

How much does the Jaguar XJ8 cost?

A Juguar XJ8 costs should range from store to store. Try the local car dealer shop first, to see if there is any Juguar XJ8. According to 'Auto Trader', the Jaguar XJ8 should cost at maximum 500.00 British pound. Therefore, if the car dealer's prize is over 500.00 British pound, try elsewhere.

How much was the 1999 jaguar xj8 when it first came out?

I have the original window sticker for my XJ8 and the cost was a whopping $59,000! That included an upgraded stereo system.

Is it possible to get a wiper blade for your 1998 jaguar xj8?

Yes, you can get aftermarket online or at a store or OE (Original Equipment) from your dealer. The 1998 Jaguar XJ8 takes 21' replacement windshield wiper blades on both sides front.

Where is the fuse for number plate bulbs situated in jaguar xj8?

The Fuse for Licence Plate Lights on a Jaguar XJ8 [1999] is Located in the Fuse Box in the boot/Trunk on the right hand side it is Fuse No.-19 and is a 5AMP one.

Where is the fuel pump relay on a 2001 jaguar xj8?

the fuel pump is in the petrol tank which is behind the rear seats. access to it is via the boot behind the carpet on back of rear seats.

Where in the engine is the ecm located in your 1998 jaguar XJ8?

Where is the Electronic Control Mo ule locate on a 1998 Jaguar Van an plas

How do you replace crank position sensor Jaguar XJ8?

under vechile near rear of engine going in from engine side toward transmission there is a 2 wire sensor with 1 bolt holding it in.

Where are oxygen sensors on 1998 jaguar xj8 and how do you replace them?

They are located high on the exhaust manifold but not accesible from the top of the engine. Had to shorten a wrench and a lot of hand manipulations with very small turns from underneath to replace them without taking the manifold off. But it can be done.

Is there a positive terminal under the hood of a 2004 Jaguar XJ8 where you can hook up a positive booster cable?

There are two batteries on a modern XJ8. One is in the trunk area.

Where can I get a Jaguar xj8 tow bar?

From Jaguar. The problem with all Jaguars is the lighting pack so if you get one from a breaker, get the light pack and wiring too.

1998 Jaguar Xj8 Problems

What oil xj8 jaguar v8 1998?

I just bought a 98 xj8 and the previous owner told me that he uses a heavier oil such as 15w40 or 20w50. If your still not sure, you can always call a Jaguar dealership and as for the service dept and ask them. They'll be happy to help. Good luck!