A quick web search and these all look to be Jaguar diesel runaway:
XJ 2.7 Diesel over reved blown engine?
Terrifying Engine runaway for a newbie
https://www.pistonheads.com/gassing/...&f=85&t=833687
tdvi 2'7 turbo
Run away xf............HELP!!!
2.7 destroyed itself – write off
S-type buying tips? - Page 3 (post 29)

I'm not sure how confirmed you want but that's for you.

 

Thanks- I don't visit the other site very often. Either I misread or did not express myself clearly, but I didn't see any runaway events occurring during a regen cycle. I did see that each event had a connection to an overfilled sump, most likely to unsuccessful regen attempt at a prior time.

 

How would they know? Their car suddenly revs high on its own. Nothing actually says regen in progress. (Not that they'd be reading the message centre even if it had such messages, which it doesn't.)

However, that is the only obvious thing that could put the extra fuel in to tip the car into that situation.

I think you'd need an active IDS/SDD session to see if the two events coincide but your average diesel driver doesn't have one let alone be looking at its display at the time of the high revs.

 

The warning light is on and they are deliberately driving the car to clear the warning. I believe this was the circumstance outlined by one of the events in the XF section.

 

OK, so it's happening during a regen. Confirmed enough?

I'm unsure of the point of flogging this - the diesel cars sometimes go very badly wrong and excess fuel (apparently getting into the engine oil) is the cause. Sometimes it causes high revs, sometimes bearings seize, sometimes the crank breaks and so on.

The only way that seems to prevent these is to check the engine oil often and if diluted / rising, change it immediately because any of the various failures may occur next time the engine is started. Perhaps/probably low probability (that's a guess, they didn't make many of these diesel cars and most will be driven by people not dying to post on the net).

 

Trying to determine what causes the engine to runaway (still don't know how the fuel gets into the combustion chamber) and whether the probability to runaway is increased during the regen process.

 

Sorry.

People don't look to have posted much detail. There again, I suppose they were not expecting what happened!

Only seems to be diesels and with DPF so if it's not regen-related it's hard to think what else.

 

Whilst I cannot confirm or deny the runaway threads - I do know that if you are a diesel newbie like me & not a member of a Jaguar forum you will not necessarily know to check the oil level for rising, and may well miss it, and even then not believe it & just think you must have missed it being overfilled initially.. bearing in mind that petrol engine oil levels tend not to be checked weekly unless you think something may be amiss and even then you are looking for a drop and may not spot a rise.

Admittedly the oil level getting way above max would purely be due to poor maintenance in the first place to be honest.

As soon as mine was just above the max I was on the case, but I am used to having older Jags and having to check the oil level every Sunday morning anyway, and hed been warned to watch for rises with this car as much as if honest I didnt believe it initially :-)

Fundamentally if you make sure you do the long runs, if the warning light comes up - immediately do a long fast run, and should the oil level rise change the oil and filter you should be OK - simples.. yes there are risks it would appear with a DPF that dumps fuel and into the oil sump of all places, but then we all drive cars that carry up to 70 litres of explosive fuel anyway - we know the risks and how to avoid them and don't worry too much :-)

It is the same with the DPF - now I know the risks, and they have been confirmed and I know how to avoid them - just monitor things and act if I need to - and definitely do not waver from the weekly checks :-) I am not as worried as I was initially now I know the issues and how to hopefully avoid them.

Nothing can be changed now but if there had been a warning light on the dash warning a purge is in progress, or even a warning in the manuals to watch for an oil level rise a lot of these issues would not have even been issues in the first place.

 

Not safe. Instead, change the oil. (Then do the run.)

What you really want is a way to check a regen has completed successfully / DPF is empty enough and there appears to be no way to know.

Be sure you have the most recent PCM software as it's the only hope it does regens often enough (if it does).

 

Ah... software.

I suppose the high revs / other issues could even be software bugs. Maybe not ever fixed bugs. Horrors.

 

Now John, you have raised a new but interesting question . . . ECU programming bug . . . and for that, I guess none of us have the answers.

I say this because, once you rebuffed my link with EGR which I based on plenty of research from my many years on UK forum with Leedsman, Buck & others, as per links proffered here, I was ready to challenge you to put up your explanation for owner reported runaway self ingestion.

If you remember, I did not state that the EGR pathway was inevitable . . . I said that research showed it was the only one that had been offered whereby raw fuel or fuel diluted oil could reach the combustion area via induction. Nor did I question destructions, just why.

Perhaps you do know of an alternate pathway? If so, explain . . . we are but disciples at your knees (LOL). Otherwise, once again, I suggest we have added nothing new to the claims by other owners and subsequent discussion.

My final
Ken

 

But how does EGR supply engine oil / fuel (or even air)?

Turbos can, supposedly.

PCV must be able to, though it feels like not much.

 

I agree that you have put your finger on the critical questions, and despite years of research, I don't have satisfying answers, nor have I learned of any from others. My skepticism is not of the fact of destroyed engines, but of third hand owner reported causes . . . who diagnosed the cause? who and how was this conveyed to owner? what was Jaguar's response, other than replacing engines to make problem go away?

After more than 10years, we have learned that lack of monitoring the oil level, probably coupled with short, stop/start driving in ignorance of the warnings clearly stamped into the Jaguar Owner's Manual, can produce the destructive price of ignoring either or both.

My frustration on the different issue of runaway self ingestion destruction, is that we don't have confidence of any pathway by which this is even possible. Via EGR or PCV? Jury sounds out, but like you I have noted once thriving firms in both UK & Oz, despite illegality, in blanking & remapping. Via lubrication into turbos? Maybe, but would expected quantities support runaway? As I admitted, your idea of software bugs sounds both plausible and one that I don't recall being raised to date.

Even more frustrating is not being able to determine known cases as pre & post 2006 . . . the known upgrade point when vast changes were made to these engine's injectors, DPF control and ECU programming. So, we can't even assert that all known cases were of pre '06 (I know several, but I can't say all), and that newer engines with post '06 updates resolved the issue (I know of none, but that does not prove none exist).

Cheers,

Ken

 

That must be roughly when the DPF was added. The problems (due to oil in the sump) all (*) seem to be due to the way extra fuel is added, late in the combustion cycle, to regen the DPF.

(*) high revs, seized engine, broken crank or whatever

The answer seems to be to buy an early diesel - or a petrol!

 

I have read all of this tread and I hope this helps to clarify that you do not need a DPF or EGR for a diesel engine to run off and destroy itself.
I had one of the first Mark 1 Golf 1500 diesel (non turbo, no dpf, no nothing at the time.) After doing some 90,000 Km I started to notice that when the engine reaches normal temperature the exhaust would change to barely noticeable slightly white bluish + the engine oil was going down to minimum by the time I take it for an oil change periodically every 6000KM.
An experience VG mechanic I had been using for many years said that VG would recommend that we change the bore sleeves and rings and that I could do a couple of thousand mile more since this was in its early stages anyway. (With time I thereafter learned that all 1500 Golfs eventually had to have new sleeves and rings.)

Anyway, a month later while driving at around 80KM, the engine took off on its own as if I was pressing the accelerator all the way down like mad. Luckily I had thought that the accelerator pedal got stuck so I left the car in top gear, slammed the brakes until it stalled and stopped.
It was not the accelerate pedal. The engine was able to suck enough engine oil due to wear and to use it to propel itself off, all by itself.
And today it is recognised that if enough diesel reaches the oil pan and if it reduces the viscosity of the oil enough - which makes it easier to go past the rings - same would happen to any diesel car.
I just bought an S Type 2.7 diesel a few weeks ago. The engine pulling power and drive is just awesome. And I have no intention of letting it go. But I will be removing the inside of the DPF and pay for a software update that eliminates the cpu routine which makes the injectors, inject fuel during the exhaust stroke to heat up the DPF and burn the accumulated sooth to ashes. As far as I am concerned, the Golf had scared me to death since this catches you unprepared and by the time I decided to stall the car down by slamming the brakes, it had reached 120KM and thank God there was no car in front of me at the time.
So I can imagine how dangerous the Jag can be with 400Nw torque and an auto gearbox this time i.e. meaning stop the car is possible - but you cannot stop the engine from destroying itself.
As far as I am concerned, this jag system borders on the edges of the unprofessional and on safety just because car makers / engineers are being pushed to the limit and hence we also start putting the endless possibilities of digital control, to bad use. Period. The software is 260 Euros and comes from the UK.
Alternatively keep checking the oil and take the risk since who on earth would risk mixing diesel with oil in the first place, however small this risk would be.