I have bought a 99 XJR with 140k on the clock.

It runs beautifully, but I have read about the tensioners and timing gear problems and wish to address it rather than risk smashing my engine up.

There is o record of any work being done on the timing gear, so need to get some newer spec parts.

Do I just do the top tensioners or the complete all tensioners, guides and chains job? Would it be a false economy to do just the top?

 

Welcome to the Jaguar family and to the forum!

First, pull a valve cover to verify that the work hasn't already been done. Good time to inspect/change the spark plugs and check for leaks around the covers.

Most only do the secondary tensioners as the failure rate on the primary ones is much lower and the secondary ones are easily done by owners. The primary tensioners/chains are more difficult and correspondingly more expensive if you are paying someone to do the work. Considering the mileage on your car you might want to consider both as much of the top work must be done anyway to get to the front of the engine.

Good links on the subject can be found alphabetically under 'Engine' in the XK8/R FAQ sticky: https://www.jaguarforums.com/forum/s...ad.php?t=29800

Might also want to scan through the entire sticky for almost everything you might want to know about the car.

 

I echo test point's view that with your mileage I would probably do both primary and secondary tensioners. That would give you the most assurance for longevity. You would probably want to do the chains as well at mileage as they have probably stretched considerably.

BTW, congratulations on the ride!

 

Thanks for the advice chaps. Will get the entire job done. I had already thought about changing the plugs at the same time.

Do you know where I can hire the tools from to do the timing gear?

 

Contact GordoCatCar on this forum and see what you can work out. That will be the absolute lowest cost solution. Gordo is the Tool Master on another forum that desperately needs new members and membership is required but free.

Only the tool kit will work on the primarily. An increasingly popular and creative 'zip tie' method works on the secondary only without special tools.

 

I'm in the UK, so that's no good.

Where can I find info on the zip tie trick? I'll tell you why I ask. My gearbox is now playing up, so my money may be better spent on the top tensioners and the box.

 

There is a discussion on the zip tie process but I cannot find it at the moment. What it amounts to is tying the secondary chain to the sprockets with zip ties and then removing the cam caps and the exhaust cam. Since the chain stays on the same sprocket teeth if you properly tension the chain when reinstalling the cam timing should be good.

Care should be taken with removing and reinstalling the cam cap bolts to ensure caps are installed EXACTLY the same way they came off. Left to right, top and bottom. Loosing and tightening the bolts should be done in half turn increments center to outsides to prevent damaging the cam.