Many agree that the V8 engines fitted to Jaguar cars between '97 and '04 are a fine piece of engineering. However some people have noticed some problems with having a slight rattle on starting the engine, which would disappear after the engine had been running for a while. This was found to have been caused by a slight slackness in the Jaguar timing chain, often due to the upper chain of the Jaguar tensioner gaining age.
Originally it was designed to trap pressurized engine oil by a non return valve, and so keep pressure against the timing chain itself. When operating normally, it works fine and no rattle is heard. However should oil bleed along the piston into the tensioner itself, this pressure is effectively lost allowing slight play to enter into the timing chain.
There have also been other problems associated with these V8 engines. For the home mechanic they have proven to be a bit more difficult to resolve. Certain specialist tools are required to do the job properly, and if you don't have them it is probably wiser to let a garage deal with them.
If the plastic facing had degraded and shattered, the chain would then travel across the metal facing of the tensioner. There would be no loss in performance, and the car would drive normally, until all of a sudden the chain would foul on the damage. This could then cause it to derail, and possibly damage the valve stems.
As stated previously, there are no indications that there is a problem. The only real way to be sure, is to a physical check by removing the cam covers. This is going to be a time consuming job, possibly in excess of three hours, but in the long run may save a heavy bill at a future date.
Gaining access to the cam covers themselves is no easy matter, it can be quite fiddly and certainly time consuming. Some specialist tools are required, if you have them, fine, but if you are considering purchasing a set can you justify the outlay for the amount of times that you will actually use them. Prior to starting any work on your Jag, ensure that you have the correct tools and all of the necessary parts to hand.
In the long run maybe it is far better to take it into a garage. If it goes into a dealership or service area, they will already have the specialist tools, and ready access to any parts should they be needed in order to fix the Jaguar tensioner. They will already have the necessary expertise, as they will have faced these problems before.
Originally it was designed to trap pressurized engine oil by a non return valve, and so keep pressure against the timing chain itself. When operating normally, it works fine and no rattle is heard. However should oil bleed along the piston into the tensioner itself, this pressure is effectively lost allowing slight play to enter into the timing chain.
There have also been other problems associated with these V8 engines. For the home mechanic they have proven to be a bit more difficult to resolve. Certain specialist tools are required to do the job properly, and if you don't have them it is probably wiser to let a garage deal with them.
If the plastic facing had degraded and shattered, the chain would then travel across the metal facing of the tensioner. There would be no loss in performance, and the car would drive normally, until all of a sudden the chain would foul on the damage. This could then cause it to derail, and possibly damage the valve stems.
As stated previously, there are no indications that there is a problem. The only real way to be sure, is to a physical check by removing the cam covers. This is going to be a time consuming job, possibly in excess of three hours, but in the long run may save a heavy bill at a future date.
Gaining access to the cam covers themselves is no easy matter, it can be quite fiddly and certainly time consuming. Some specialist tools are required, if you have them, fine, but if you are considering purchasing a set can you justify the outlay for the amount of times that you will actually use them. Prior to starting any work on your Jag, ensure that you have the correct tools and all of the necessary parts to hand.
In the long run maybe it is far better to take it into a garage. If it goes into a dealership or service area, they will already have the specialist tools, and ready access to any parts should they be needed in order to fix the Jaguar tensioner. They will already have the necessary expertise, as they will have faced these problems before.
About the Author:
Christopher's Foreign Car Parts. specializes in Jaguar timing chain replacements. Visit them online for details! (http://www.christophersforeigncarparts.com)
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