Plausible, yes.
But I would have expected an engine sounding like a bucket of bolts at the “startup” period at the occurence.
I see the oil change was done. Hopefully not a “flush”. As “startup” is the sensitive time, I hope the oil is 0W30 weight.

Back to the issue, I’m afraid you’re in for an investment.
Be sure to change the timing chain tensioners, the guides, the chain itself and all the actuators.
As I learned with a few engines over the years, only use OEM parts. Or you’ll be back in this predicament before you know it.
If its any consolation, the service on the 308 GTS (no, it was not the ‘i’.) was VERY expensive when we hit 50,000 kms. You’re well ahead of the game.

Care to share the financial estimate?

 

I also have never heard of a timing chain slip on these cars. No idea about LR though. I've been in this forum for 9 years now.

 

Sadly, it is a well-recognised problem with the chain tensioners on the 5.0 V8's. The later design is a 100% fix. If the rattling is ignored it can eventually result in a one tooth jump, which does not cause valve - piston contact or, in the worst case, a two tooth slip which is usually terminal.

However, as I suspected above, the ODB faults will clearly indicate the nature of the issue.

Timing Chain Problems 2010-newer Jaguar Land Rover AJ V8 Engines - JE Robison Service - Bosch Car Service Specialists ? the blog

Richard

 

Okay, I'll accept the notion of your reference and consider it valid.
That still doesn't equate to the overwhelming lack of evidence in this forum.
Maybe all us Forum old codgers are immune from chain stretch and subsequent tooth-jumping?

 

edmundj: Noting that the "only" codes posted are all P codes -- are you (or they) checking the car with a JLR fully compatible reader?

More to the point: are you seeing these on your reader, or are they telling you these are the only codes?

Seems really weird that the codes are only misfires, and only on all cylinders. I'd expect to see others.

Ask them to give you a complete engine status readout from ODB: all the engine conditions their ODB system can capture. Then post it.

Consider all things they "fixed": I notice they replaced the fuel filter. What's the fuel pressure reading at the engine? Replaced air filters? What's the MAF voltages, and the fuel trim? The MAF's are right near the air filters they supposedly replaced. And so on.

(Skeptical of a "timing chain slippage" that happened while they worked on it. With the "bad cat" statement, it smells like "let's guess it's this" diags. A slipping timing chain would cause a lot of other things and codes.)

You need to take a "show me and prove it" attitude towards their diagnostics conclusions. Slipping chain? Show the specific measurements that cause the mechanic to make the claim. And so on.

 

That would be one hell of a feat to accomplish on a 2012, since THEY DON'T HAVE FUEL FILTERS.
What ELSE did they SAY they did but didn't actually do? This is highly suspect.

 

Heh...good catch. He should look at the invoice to see if he was charged for one....

 

Motorcarman has a couple of TSB's related:

https://www.jaguarforums.com/forum/a...-diagnosis.pdf
https://www.jaguarforums.com/forum/a...erformance.pdf

Relevant to S-type, but a major leak is a consistent problem. If the techs replaced the air filters, it can be very easy to badly remount the air pipes.

The owner had almost identical codes listed. Speaking as one who screwed it up, it's easy to get the long chain of air pipes wrong.

 

Has anyone bothered to read the fuel pressure?

Is any smoke visible when the misfire(s) situation occurs?

Is there a raw fuel odour with the engine running?

 

Good points. Edmund hasn't been back for a couple of days.

I hope they haven't sold him a new engine by now.

 

Hi All,

Thanks for all your replies! So bit of a pause over the weekend and then the car is going for a second opinion before we throw money at the problem. I am still working on the assumption that it is a timing chain slip until I have had the second opinion that might find something else. I will say that the car did have a rattle at idle which does seem consistent with a timing chain problem. Still very much hoping this ISN'T the problem as I am sure it will be painfully expensive to fix if it is.

From the various people I have spoken to (including on this thread!) half say timing chain slip is a known issue with those 5.0L V8s and need the new design tensioners to sort... and half say they have never heard of timing chain slip on these engines and they are solid as a rock. ...?

Ill need to get a truck to move the car to another garage which should be on Wednesday. I'll ask for a full read out of the codes to post on here once that is done.

 

Timing chain tensioner failure are a well known problem within a certain VIN range, even to JLR who’ve redesigned them. The timing chain also at one point was re-engineered. There’s a thread here about it I’ll see if I can find.

 

The half that have never heard of the timing chain tensioner problem are simply the ones who have not done much research.

https://robisonservice.blogspot.com/...er-jaguar.html

Richard

 

I don’t mean to be inquisitive, nor do I expect a reply.
I see these posts @edmundjbradbury are all relatively new. If you purchased the car at the dealer within the last year, is it worth your while to take it back there? I’m with @GGG , I expect there is a simple root cause. Be sure to ask this other shop if they subscribe to the Jaguar Topix. Or source another shop.

 

https://www.jaguarforums.com/forum/x...-chain-246239/


https://www.jaguarforums.com/forum/x...-techs-159928/