I want to replace the tensioners on my 99 xj8, I know they are bad because I can hear the damn chain starting to rattle. I need info on where to buy the best tensioner replacements and maybe a tutorial on how to do it . Any suggestions or tips are much appreciated. If this job is too difficult for me I will just take it to a mechanic since I’m not very mechanically inclined.

 

I've done this job on both of my 308's, and I have to say, it's not for the meek. It isn't an enormous job, but it's like cutting dovetails by hand like on The Woodright's Shop. Roy Underhill says the hardest part is getting your mind right and keeping it there in spite of outside influences, and having the proper tools. I made my own camshaft hold-downs for the first one, bought the tool set for the second.

I bought the tensioners from two places, prefer the set I got from Christopher's.

 

Yeah Im better of taking it to a mechanic then , I don’t want to risk breaking something. Thanks for the advice

 

Forgot to ask , is it necessary to replace the whole timing chain and all the other parts or just those cheap *** plastic tensioners?

 

It is difficult to advise with limited information.
Does it only rattle for a few seconds on start up? Then it may only be tensioners.
Does it give the occasional rattle during running? Might be VVT and can be helped with changing oil viscosity.
Does it rattle on start up and during running? Then might be main chain guides.
You don't state how many miles are on the engine. If it is much over 75,000 and you are getting rattling then I would go for full chain and tensioner replacement.
Your best bet would find a good independent Jag shop and have them take a look. Repairing a Jag by replacing parts without a good diagnosis gets to be very expensive.

 

Yeah it rattles when I’m driving and on start up also , It has 98,000 miles and i use 5w30 synthetic blend

 

By the time you are out driving both the primary and secondary tensioners should have fully pumped up. They tension by oil pressure. I would look at full change out. You will be good for another 100k

 

Good advice on this thread! You may also want to familiarise yourself with the repair process with a read through of the Workshop Manual.

Most of the time the primary tensioners and guide rails have worn or cracked at that number of miles, so it is false economy to just replace the secondary tensioners.

Here is a link to some useful information on the X308: https://www.jaguarforums.com/forum/x...-issues-43702/

 

Eddie, not hard to do at all. Go to XK8 forum, sticky DIY page down to replacing timing chain tensioners, I did this on my XK8, same engine and super simple, sticky has pictures and step by step instructions, replaced top tensioners and valve cover gaskets, took less than a day. Again super simple and easy to do. Shop around for tensioners, it's been a couple of years since I did the job,

 

Eddie, don't click on the links, go to Primary/secondary tensioner replacement Matt (H2Oboy), should mention wire tie method, u don't need special tools etc etc.

 

yeah thanks for the info , I’m sure I can do this myself ! You have any good website to buy the upper tensioners ??

 

do I need to replace the guied rails also ?? Since they are also made out of plastic

 

Hope you don't mind me jumping in, as I had similar rattles, so I changed the lot?

These are critical components to the engine, and if any of them fail, it's a major (and damn costly) repair, even down to needing a new engine! My advice is don't risk it, change everything (Primary and Secondary chains, Tensioners, and Chain Guides, everything) just to be sure. Take everyone's advice on here, I did, the people who describe the process on here do it from experience, and that's invaluable.

There are some 'special' tools required to maintain the valve timing correct.. a 'plug' (fitted where the Crankshaft Position Sensor goes, this holds the engine in the right place) and some fixtures for holding the camshafts in place... just beg, steal, or borrow the tools...lol.

Follow advice/instructions in the manual meticulously and you'll be fine. I found the most difficult job was undoing the Crankshaft Pulley bolt (don't use the plug holding the engine still to undo the bolt). I used a crowbar at the flywheel access to hold the engine still, and once the bolt was loose, THEN I fitted the plug.

PS: You might want to check which cooling tower you have fitted when you do all this, if it's the black plastic type, change it for a metal one. I also fitted a new Thermostat and Temperature Sensor too. These jobs are much simpler with the timing chain cover off! In addition, while you have excellent access and for the cost, it might be worth replacing the Water Pump?

 

Eddie, watch the video from Matt, I changed the top tensioners and not the guides. No special tools needed, follow Matt's instructions and you'll have no problems, wished I could talk to you may be if I try this: three three four seven three three zero one three three. Scott

 

Eddie, some more suggestions: Parts Geek for parts, they have the whole kit for $484.48, this includes everything you need to upgrade. They have individual parts if you want to go that route. Go to Youtube/yahoo and search Jaguar XJ8 timing chain tensioners 4.0 engine, look at videos and images it will show you what plastic does over time. Recommend you do not hesitate to upgrade.




Scott

 

See post number 8.

With the age of the components, DO NOT just change out the secondary tensioners. Remove the timing cover and replace the primary chains, tensioners and guides as the primary guides are most likely cracked or already broken.

Follow the procedure in JTIS using the special tools to hold the crankshaft and camshafts.

 

Ok I’m taking it my mechanic here soon , I just need to get him the special tools found these on eBay , https://m.ebay.com/itm/Jaguar-97-08-....c100694.m4598.Isthis all I need in regards to the special timing chain tools ???

thanks to everyone for the advice

 

Also do nd this kit for $99 bucks on eBay looks legit ??https://www.ebay.com/i/272565986214?...D1340285114676

 

Ok I just ordered the timing chain kit , can you give me a check list on what else I would need ,

Timing chain kit
Water pump
Gaskets
Etc...
Thanks in advance

 

I recommend a valve cover gasket kit. Don't forget to replace the plastic thermostat housing when you can. Good Luck.