I have a slight knocking in my 2014 XJL 3.0. It seems like it is time to replace the timing components. Does anyone have a list or advice on what parts I need to replace. I am going to purchase the parts required and deliver car and parts to the mechanic. I just want to make sure I get everything needed so there is no delay in fixing once the process begins. As always thank you in advance for all the wisdom and insight provided by this forum. Very much appreciated.

 

Before springing for those parts and paying (a lot!) for the labour how sure are you that the "slight knocking noise" is caused by one or more faulty/worn timing chain components? Coz if this were the case it would be more of a rattle than a knock whereas the infamous SC coupler / torsion isolator rattle could also be described as a "slight knocking" and on a 2014 it is just as likely to be worn as the timing chain components. Unless of course you have already had the coupler replaced!
One clue is that the timing chain rattle is quite regular and rhythmic while the coupler rattle is very irregular like marbles in a tin can.
Another clue is that a worn coupler will often give off a loud "clonk" on engine shutdown, as that is the sound a worn coupler makes when the internal spring rebounds on shutdown.

 

The car was sent to a reliable Jag shop and they are the ones that told me it was a timing issue. So I am just taking their word for it. Unfortunately they also wanted to charge a crazy price to fix. Because of the price they quoted I decided to go a different route. I have a close friend that is a high end mechanic and reluctantly talked him into doing the work. He said if I get the parts he will install and repair. So here I am trying to make sure I get the correct parts.
The coupler has never been replaced.

 

Z20, mind if I ask how many miles on your clock? I also have a 2014 XJ 3.0 L and want to know how soon I may be faced with the same issues.

 

I reckon you should get a second opinion and have your mechanic friend listen to the car/engine.
A year or two ago the boss of my favourite independent workshop (who specialise in Jags) - not a mechanic himself - was adamant that my AJ126 V6 needed a full timing chain replacement after simply listening to my explanation of the engine rattle. He didn't listen to it himself and I had the coupler replaced under warranty several years ago and I strongly suspect my rattle is the coupler again. He said, from memory, "they all do that (referring to the AJ126) we have replaced heaps of timing chains" and he quoted me over $7,000 AU for the job. I declined the offer and other than a noisy/rattly engine I have had zero engine problems, and that's with a pullied and tuned engine. Also remember that the AJ126 is an inherently rattly/ticky engine anyway, not just the coupler and/or the timing chains but the fuel injectors, fuel pumps and SC belt tensioner as well. Point is many dealerships and workshops are quick to blame the timing chains on this engine as it's a good money spinner for them when there are plenty of other possible reasons for a rattly engine.

Edit - forgot to add - the AJ126 came out in 2012 and from the get go it had the updated/revised timing chain components that were introduced on the AJ133 V8 at the same time - stronger timing chains (8.00 mm pitch vs 6.3 mm pitch) and redesigned tensioners and chain guides. For this reason the timing chains on the V6 are nowhere near as problematic as they are/were on the older V8.

 

Also, don't get me wrong, I'm not saying that your car definitely does not need new timing chain components, it might very well be that, but that you should investigate other possible causes first as renewing the timing chains (and tensioners and guides and cam sprockets as they all must be replaced as well!) is a big, labour intensive and very expensive job.

 

@ OZ Thank you for all of the information.
@ Freddy, the Jag has 82k miles.

 

Good info from OzXFR!
Remove the SC belt then start the engine. See if the noise is there or sounds different. I also am leaning towards the SC snout noise.
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Hey Z20!
I have a list from a 2011 XJ 5L we did the timing chains on. I put your vehicle into our parts look up system and it looks like the timing chain, timing chain guide rails (upper and lower) and the chain tensioner are the same as the 5L. The valve cover gaskets are different: part numbers AJ813020 right AJ813023 left. Some of the parts on this list we had to replace once we were doing the job and noticed they were cracked, brittle etc. Anywho, here is the list from our customer's repair order!


I hope this helps! Sabrina

 

Agree with others’ comments. Timing chain/tensioner issues are less common on 2014 V6. I have a lengthy thread about my timing chain/ tensioner/ supercharger snout replacement on my supercharged 2010 V8 with lots of part numbers, if it helps. But again think it’s less likely.

You can also check out the driver-side chain tension by opening up the oil cap and pushing on the visible chain with a finger or screwdriver. Should be fairly tight. There is a YouTube video of someone doing this test before/ after replacement on a 5L JLR engine (I think a Land Rover), showing the difference in travel.

Not the same video, but here is an example of bad tension:

Best of luck!