Another timing chains thread!
 

A question for the group.
On my MY 2015 (build date Oct 2014) V6S F-Type do I have the early problematic 6.3 mm "pitch" timing chains or the later not so problematic 8.0 mm pitch chains (and the associated guides and tensioners)?
Coz the boss of my local Jag shop is trying to tell me that I have the older chains, guides and tensioners and they are the cause of my pronounced engine rattle.
He has said so without even taking off the oil filler cap to have a squiz at the top of the LHS chain, just that "the rattle is always the timing chains and we have done heaps of them". He also reckons that the updated timing gear wasn't put on the AJ126 until some time in 2016.
I have had a gander down the oil filler hole and AFAICT it has the later chains.
My research tells me that the AJ126 came with the updated timing gear from the get go in 2012 and it was the AJ133 (V8) that was updated in 2014 then again in 2016.
Maybe the AJ126 timing gear was also updated in 2016, ie a second update?
Thing is he is quoting me $5,000 to $7,000 to replace the chains, guides and tensioners and I am loathe to go ahead with that if the engine already has the updated gear anyway. Conversely the engine really is very rattly and maybe the chains are about to let go and destroy the engine, although I haven't heard of that happening on the AJ126 just the earlier AJ133.

What is mileage on your car?

I fought chain issues on Mercedes V8 and chains tend to stretch _only_ with miles. If you don't drive it much, it doesn't get used up. Additional issues, like plastic guides going brittle and tensioner getting bad from sitting takes decades and should not be an issue on 2015 until well into 2030s. Also, chain issues often co-symptomatic with startup chain slap and you can detect that with stethoscope.

Last but not least, I don't know what it takes to do this job on AJ engine, but on M116 engine it only cost me 2K as there is a method to feed the new chain through with just valve covers off. Even if you factor extra steps for SC removal on AJ engine, I can't see it exploding to 5-7K.

My suggestion is to look at alternative explanations for your rattle. Like supercharger coupler.

Currently at 65,860 km (= 40,923 miles).
I bought the car in Sept 2016 at 20 months old and 27,xxx km on it so I have done some 38,000 km since in 4.8 years or around 8,000 km (5,000 miles) per annum.
I don't know how often the previous owner(s) changed the oil but it is odds on to have been per the service schedule so 12 months or 26,000 km whichever comes first which means one single oil change when I got the car. Since then I have religiously changed the oil and filter every six months so less than 3,000 miles between changes.
I have a car stethoscope and have used it quite a bit but the engine has so many noises and rattles it's hard to pinpoint anything, the best I can say is the most obvious and loudest rattle is from the top/front of the engine.
I had the coupler/torsion isolator renewed (the whole snout) under warranty just on three years ago, but that did not "fix" or really even reduce the rattle although the tell-tale "clonk" on shut down was fixed and has not returned. But as the dealership that did the work undoubtedly used an OEM coupler with the steel spring inside (as opposed to the later solid plastic coupler) it is possible that the spring is rattling again and/or the shaft is gouged.
I have considered alternative causes of the rattle such as worn SC tensioner (replaced by the dealership under warranty just before the coupler due to incorrect diagnosis), secondary high pressure fuel pump bearing wear and coolant pump bearing wear but the rattle doesn't really sound like any of those and the more I listen to it the more it sounds like timing chains to me. It's quite a high pitched, fast and regular rattle, not the deeper, slower and irregular "marbles in a tin" worn coupler rattle.
I have priced the parts for a full timing chains, guides and tensioners replacement including gaskets and it comes to less than $2,000 AU, so I reckon the quote I have received includes a fairly inflated labour charge although I know it is a labour intensive job.
But back to my original question, does anyone know for sure which version of the timing chains, guides and tensioners I have????

Oz: I cannot comment on the noise you are hearing but the issues around the timing chains seem to be limited to the earlier V8S, including the widely publicized US lawsuit. Despite trying my best, I can find no real documentation of issues with the chains in the AJ126....and while the lawsuit just mentioned claims that on the JLR V8 problems can surface as early as 80,000 miles (!) it is recognised that in general, meaning not specifically on Jaguars or Land Rovers, the "normal service life" of timing chains can end anywhere between 80,000 and 120,000 miles.
Frequent oil changes, such as you have done, are seen as the best way of prolonging timing chain life.
I do believe that the V6S engine fitted in the F-Type benefited from the more robust chains from the beginning.

Inquiring minds want to know:

Are there any pictures of what the different chains look like (in the car)? :confused:

Or, how to identify.




Thank You.

:icon_hijack:

Yep, there is a post or two around here somewhere showing the different chains side by side, and it is those pics which lead me to believe I have the later 8.0 chains.
I'll leave it up to better searchers than I to find the posts/pics!

This jogged my memory and I recalled reading statement from JLR VP that all V6 engines had updated timing parts from day 1. Which makes timing chain diagnosis less probable. More so, considering low miles on the car.

I haven't been able to find the pictures of the two widths of chain. :icon_bricks:

Anybody know? (I'm well aware of how different SEARCH terms can help or not...)

shown in my favored thread on this forum

https://www.jaguarforums.com/forum/x...177468/page20/
#388

Regards
Ulrich

THANK YOU. (I did search other recent model forums but not 'engine rebuild')

Oh, and Posts 397 and 399 show pics of the chains as viewed through the oil port. :p

Sorry to read of the trouble you have been having with the ftype OZ , I have read of it before on your other posts on various forums you have posted on and hear in the past , surely the dealer had put in the old spring type coupler in your car when they replaced it , Obviously with a new old type one . $5-7000 for new chains that can't be right , Ripping the proverbial if you ask me . I sincerely hope you get to the bottom on this issue once and for all , as you are a most helpful guy to other forum members and to any one reading your posts . I just had a look at my buddy steves chain he has a 2011 xkr convertible, one owner before him , looking through the oil cap it looks like he has the newer 8mm chain as seen on the photos . I take it they also replace the tensions with the newer steel ones at the same time , well one would thing so . On his service records and documents al it says , is work carried out else were , I take by reading this that the first and previous owner took the car to a Indy garage to get the work done . George

Yep, that's it!
I just had another squiz down the oil filler hole and I am now 100% certain I have the later/beefier 8 mm chains on my car.
Which means it is unlikely my engine rattle is caused by the dreaded timing chain wear or looseness, which is a huge relief.

could the noise be coming from the blowet snout?

FYI, if you want to link to a specific post, click on the post # in the upper right corner. Then copy the resulting URL.
https://www.jaguarforums.com/forum/x...0/#post2284502

FYI, The 8mm is narrower width wise than the 6.5mm. The measurements are based on pin to pin distance not how wide it is.
https://www.jaguarforums.com/forum/x...0/#post2287227

Agreed.
But in my feeble defence I will claim I was talking about the width of each link!

OK, now I am TOTALLY confused. In the photos of the two chains which is the 8 mm, newer chain? I assumed it was the wider one.????

This is the chain on my 2015 F-Type, build date 02/14 - is this the 8mm chain?

https://cimg9.ibsrv.net/gimg/www.jag...8d7046e1f8.jpg

yes

Agreed, mine is the same.
Excluding the cover plates the older 6.3 mm pitch chains have 9 links across while the newer 8.0 mm pitch chains have only 3 links across and those links are much wider, thicker and beefier.