Hello,
Does anyone have an idea at what mileage Jag recommends replacement of timing chain tensioners on a 2012 5.0 N/A. I purchased mine a little late in it's life and I get to change out leaking valve cover gaskets, lucky me. Thinking while I'm in there, I should take care of other things that will eventually go. Also curious, if anyone might know if Jag would have service records on this beast that might indicate what, if anything, might have been done.

Brian

 

Brian, you can always try your local dealership and see what they can find for you. Also, as silly as it may sound, get a CarFax on your car. They have been putting service stuff there too.

As for service lists and whatnot, you can go to jaguar.com and inside there, you can download all the manuals electronically for your car. That will have the list of recommended service intervals. There is no recommended interval on the timing chain that I am aware of. I drove my 2012 out to 140K miles on the factory timing chains with no issues. So, unless you are bouncing off the rev limiter a lot, I would wait for it to start making the ticking sound and replace them then. The bigger thing I would be going after since you are getting in far enough to do valve cover gaskets is to replace the coolant piping that is plastic with the metal aftermarket stuff. This would be a good time for that. There are like 7 pieces that you can get to essentially bulletproof the coolant system. Get those (run you like $350 in parts) and do the coolant system. May be a good time to do the spark plugs if you do not know when they were last done. You are going to have the coils off to do the valve covers. So, you are just needing to spin the spark plugs out.

 

Hey Thermo
Thanks for the reply. They say timing is everything in life. Unfortunately for me I find out now about aftermarket metal coolant parts, yea I through down about 3 big ones at the dealer for OEM. So I'll assume they are plastic. First and last venture into a dealer's service bay. Also will wonder over to the jag site you mentioned and have a peek see. I'm of the mindset that I'll keep this one the road for a bit. So long as I don't get hammered from the rear like I did in the XK8.

 

CC, don't worry too much about missing out on the after-market metal coolant pipe replacements, most of them are for the SC version of your engine (AJ133 V8) and the related V6 (AJ126, SC only) and only a small number of these metal parts are also for the NA V8 like yours.

 

And the genuine parts are fine, surely last at least as long as you keep the XJL.
The aluminum aftermarket parts are too new to know how well they hold-up, and they have joints that will leak over time too.
If you look at them they have seams that need gaskets or RTV, and over time that will degrade & need service too.
So don't regret not getting them. Feel great in that you replaced the weak parts before they failed, and you've got many years & miles before they fail again.
That said, keep in mind there are other parts that will need replacement too - browse the existing forums to read whet problems people post most about & decide how it applies to your own vehicle.

I replaced the cooling system parts on my 2012 5.0L NA Range Rover & wife's 2012 XJ with the same engine, both with over 10 years & 155k+ miles. and most parts I replaced may have lasted much longer at that age.


And I'm replacing the cam chain tensioner on the RR right now.
This is how they looked when I opened it up.
It has the earlier tensioner design, and they look fine - not too shabby for 161k miles...

 

The issue with the chain guides can't be seen until you remove them. It's where the plungers for the tensioners impact the back of the chain guides.

 

My old guides and a new guide

 

Mine were where I could see that there wasn't too much wear into the rail because of how far/deep they were extended. Not too bad for 12 years/161k miles.
When you remove them, the tensioners extend fully, but looking at them before I pulled them I could see that the plungers weren't extended too far.
The rails didn't have much wear on the friction surfaces of them, and the plungers had plenty of travel.
This is what my rails looked like. Worse than yours just above, but better than I expected.

 

The issue is not the plunger but the wear in the tensioner can get to the point that the plunger is "locked" to the tensioner and the chains do not have the proper tension and get loose.

 

I'm kind of surprised that the original tensioner design made it through to the final product.