Greetings, all. I have unashamedly lifted the following from an earlier (2018 thread) because it accurately described the problem/issue I am experiencing with my 2012 XK Portfolio. Recognition and apologies to the originator. "2011 XJ with NA 5.0 liter, 67,000 miles. On warm restarts, after sitting for a few minutes, it makes a knocking sound which resembles a bottom-end knock (rod or main bearing). However, revving at 1,500 or so RPMs for 20-30 seconds, or driving a few blocks, will cause the knock to disappear. The knocking only occurs on warm restarts, never cold. It will knock when started within a few minutes of shutdown. After an hour or so of sitting, it may not knock".
The dealer diagnosed worn timing chains and tensioners with a quote to repair of $34,000. That's AUD not USD, but still eye-watering to say the least. And half the current market value of the car. The reason for the amazing quote is they (the main and only Jaguar dealership on the Oz west coast) are unable to determine without a strip down if the engine has a 6.5mm timing chains or an 8mm ones. If it is a 6.5mm, which is no longer available a fix would require an engine out and replacement of literally the front end of the engine to fit the 8mm chains. I have no reason to doubt the dealer's advice as I have a longstanding and strong relationship with the service staff. This notwithstanding, I am still a tad perplexed! Firstly, why doesn't Jaguar/Rover know what the specs of their engines are, and they don't according to the dealer? Surely there are 6.5mm chains and associated bits in a spare parts department somewhere in the world? I'd be willing a decent wager that would be in the US, somewhere. Assistance/guidance on the following questions would be most welcomed, please:
1. Has the issue of the knocking sound on warm start up been resolved yet? I have followed the 2017-18 thread but nothing definitive as to what is the cause and the fix.
2. Is it just one of those unexpected benefits of owning a Jaguar - the noise, that is? And I should just turn up the sound system. I should add there are no obvious driveability issues - no loss of power, changed fuel economy or dash warning lights. I'll get those tomorrow, now that I have tempted Karma!!
3. Is there a way of determining the chain specs (width) without stripping the engine from the VIN or block serial?
4. If it is 6.5mm, is chasing down a spare viable using the dealership networks in the US?
5. This old chestnut - which I don't subscribe to - is it a Ford engine and should I be talking to the local Mustang dealerships?
Cheers
(The XK is the one on the right!)

 

Yes, I was flabbergasted at the cost of car maintenance in Aus.
And I am surprised to hear that there is no way of knowing the size of the timing chain by using the VIN. Perhaps a tech can weigh in on this.
At a quote like that I’d assume they were rebuilding the entire engine and replacing ALL wearable parts, including the aspects of the transmission… perhaps even polishing out casting marks!

But to the point, I suppose it is possible at 67k miles that the timing chain and/or tensioners…
Need to ask… is the oil fluid level precisely right? A level on the low side would not be helpful. And in that engine in particular, where the oil takes a bit of time to drain after a shutdown, it seems of a low oil situation to me.

As for going to Ford, maybe. But don’t kid yourself. It may be a Ford block…. but there’s some specific Jaguar technology there.
Following with interest…

 

Guy, thanks. I should have mentioned that the car has traveled 82,000 kms about 40,000 miles. The oil level, quality and specs is not an issue to the best of my knowledge. Electronic dipstick does not move between services - oil changed by the dealer every 6 months or so as this is not my daily drive so never reaches the book servicing interval. You get used to the maintenance costs - as they say 'if you can't handle the heat then get out of the kitchen'!
Cheers

 

timing chain pitch with photo of difference https://www.jaguarforums.com/forum/x...-chain-246239/

5.0L timing chain noise from misbehaving hydraulic tensioners https://www.jaguarforums.com/forum/x...-techs-159928/

 

Cheers, jons. Significant difference between the two chain types. Must admit the 6.5mm looks the quality part and I would prefer to maintain originality if possible. The real question is where would a NOS one be found?

 

First thing first determine exactly what and where the noise is .

​​​​​​ Rod "knock" sounds completey different to timing chain "rattle".

Get this up on a hoist with the engine running and it will make it a lot easier to determine whether the noise is coming from underneath the engine (con rod knock) or rattle coming from the front of the engine (behind timing case) .

If rod knock you might be lucky and have a chance of simply replacing the big end bearings on the conrod/s providing the crank isn't scored this can be achieved from underneath through bed plate ( e92 4.0 m3 are also notorious for bearings failing)

In regards to the chain thickness remove the valve cover and yiu should be able gain sight to the chain in order for it to be measured. A timing chain is big but shouldn't be more then 4-6k it's a two day job

 

sump removal in order to inspection con rod bearing (on lift from underneath vehicle)

 

Hi,
Give UK Autocare in Wangara a call. I had this done last year and paid less than half of that - with significant other work included (new supercharger, head done etc.).
Superb job done. Feel free to pm me for details /copy of invoice etc.
Cheers,
Rob

 

Thanks, steve_k_xk. Pretty sure it is the front of the lump and not the con rods. Roger on how to measure the chain. $4-6k is a prettier number. Cheers

 

RobB, Thanks. Encouraging. Happy to catch up for a chat. What are the rules re direct contact? Beach suburbs. Cheers

 

only difference is the 5.0 doesn’t have a bed plate to get in the way. the crank bearings have caps

 

Even better then .

 

you sure its not your supercharger coupler? Can sound like engine knock but is much cheaper to fix

 

The rule re direct contact used to be that whoever got the help buys the beers, but the admins banned it because CeeJay's liver couldn't hack it.
I'll just PM you..

 

 

Supercharger? Mine's the poverty model! Could fit one I suppose.

Cheers

 

Nope. Different engine. Too high compression and VVT.

 

Poverty pack haha hardly with a purchase sticker of 200k AUD or so new

 

Don't want to state the obvious but s/c also has vvt but no cam phasing (phasing only on inlet ) however cee jay is spot on about the high comp

 

Yeah, that's what I meant...