Hi All,

My 2012 XKR is very sick. Any suggestions helpful.

I had was annual serviced at a trusted independent last week having been running sweet as a nut, (all the usual, oil change, filters etc). Report was all clear, but advisory that I would probably need to change spark plugs on next service as they haven't been changed since new (78,000 miles)

Picked it up and it was running fine around town, but first time I opened it up on a slip road it went into Limited Performance Mode and lost a lot of power. When I pulled over the idle was extremely rough (rocking the car from side to side), car surging, and if left in idle for more than 10-20seconds the engine dies. If put the car in neutral when coasting the engine dies too.

On cold start, the engine is rough but running, but as the overrun stops then the idle gets rougher and rougher and then dies.

The error codes as read by the RAC were:
- P0301 - Cylinder 1 misfire
- P0302 - Cylinder 2 misfire
- P0303 - Cylinder 3 misfire
- P0304 - Cylinder 4 misfire
- P0305 - Cylinder 5misfire
- P0306 - Cylinder 6 misfire
- P0307 - Cylinder 7 misfire
- P0308 - Cylinder 8 misfire
- P0300 - Random misfire Detected
- P0316 Misfire detected on start up (first 1000 revolutions)

It has obviously gone straight back to the garage who have approached the problem by changing ALL cylinder sparkplugs AND coils... Whilst I accept that might cause misfiring in one cylinder it sounds surprising that they have all gone at the same time! Is there anything that could have happened during the service to cause this? I was thinking fuel line blockage, air intake leak, camshaft position sensor...?

 

Logic says that they did something during the 1st service that caused the problem. The engine won't just fail and all plugs won't go at once. I assume that the service place will not charge for the fix.

 

I’d have to agree with both of you.
The odds that all coils and spark plugs are unserviceable at precisely the same time?? Best buy a lottery ticket while you can.

Perhaps its the camshaft position … but you didn’t throw the position code.
Perhaps the MAF… but no MAF codes
Perhaps the cats, but no O2 codes.
Perhaps the injector circuit… but no circuit codes.

please elaborate on “all the usual”.

 

I agree with all that.

I hope you are not paying for any of these new parts as the garage seems to be incompetent and the cost will escalate to £1000's if they continue with their amateurish "change everything" approach. What codes has the dealer actually read? Was there anything at all on the MAF/intake side?

It must be something which affects all the cylinders and the obvious service candidate, as listed, would be something on the intake side. Blocked intakes due to incorrect, faulty or wrongly fitted filters might be a remote possibility.

Did they touch the battery/electrics although I would have expected codes and other symptoms if it were a battery/electrical issue.

Richard

 

The garage now say having replaced all the coils and all the sparkplugs that the performance limited warning light is now off but the engine is still not running smoothly. The right hand side bank seems to be good, but the left is staying cold and not firing properly... so their current theory is left catalytic converter blocked. They are going to investigate this today.

... I am a bit surprised that this would not have triggered an oxygen sensor warning...?

 

I always like to eliminate the simple things first before throwing money at an issue.

As the vehicle was running perfectly BEFORE the service, the most likely explanation is the multiple misfire is caused by something removed/refittted and/or disturbed as a direct RESULT of their skilled attention. Top culprits would be introducing a major air leak on the induction side throwing the fuel trims haywire or an improperly refitted harness connector to a sensor which loosened when you opened it up.

Graham

 

Whatever the problem was, it was not the spark plugs or coils, so I'm afraid the garage are talking rubbish about the right hand bank unless they have done something else as well.
A blocked cat converter would throw up a load of codes. ODB was invented primarily for emissions problem analysis and a failing converter would be it's bread and butter. Surely the garage have a decent Jag ODB reader if they purport to be Jag specialists? It is not inconceivable that running the car is a serious misfire condition could affect the converter efficiency but it's not the converter which has caused the misfire situation.

I would still bet on the intake/filter pipework/sensors being mis-fitted.

 

was you getting any converter fault codes?Might be a piston...1 time i went to go get a coolant hose changed at the dealership once and they left a shop rag paper towel in my air intake and it got sucked up by my throttle body and almost went into my engine and left my car acting like it didn't want to run.My lil brother took the intake hoses off and throttle body off and found the shop rag stuck under the throttle body.I was pressed to the point where i was gone try to file a lawsuit against that dealership but i didn't all because i feared it might put the whole company out of business if i won and if i did have a case on my hands.A question about that,could i could have filed a lawsuit about that if anybody knows in case that happens again if i wanted to?

 

Good morning.

I see, according to the checklist, they touched the throttle body. What did they do there?
Replaced filters. As its an R, what filters were used? Are they the same?
Checked breather assembly. Did they mess with it?
Did they replace the oil cap? And not cross threaded? (though I don’t know how one could cross thread it… but I’ve seen it done!)
Did they touch the supercharger?

Despite the rumors, I find these cars very resilient, If properly handled.
Are there ANY other codes?

 

One thing nobody has introduced... stuck High Pressure fuel injectors. They can make a mess of running engines. Your initial symptoms are identical to the ones I had when one of my injectors took a poo.

 

It would be a coincidence if this happened during the course of a routine service to all the injectors but, of course, not impossible.

When it happened to you, did you not register a fault code relating more closely to the injectors?

Richard

 

Only takes one to go bad, then the pressure on that entire side is foobar’d.

 

When an injector goes bad, and as kj just stated, that bank is gone. Two opposite injectors and both banks gone.
The only codes that comes up are...
- P0301 - Cylinder 1 misfire
- P0302 - Cylinder 2 misfire
- P0303 - Cylinder 3 misfire
- P0304 - Cylinder 4 misfire
- P0305 - Cylinder 5misfire
- P0306 - Cylinder 6 misfire
- P0307 - Cylinder 7 misfire
- P0308 - Cylinder 8 misfire
- P0300 - Random misfire Detected
- P0316 Misfire detected on start up (first 1000 revolutions)

One additional thing to consider, the only fuel filter on the 5.0 cars is a sock on the fuel pickup inside the fuel tank. Maybe for some reason you got some gunk where gunk should never be.

 

It says they added fuel treatment. Do you always have that done? What was it they used & could it have dislodged some dirt or scale that’s gone somewhere it shouldn’t?

 

So two injectors would have to jam fully open, one on each bank, and both at exactly the same time. It's an unusual fault anyway and for this to happen in this configuration would be almost unbelievable which suggests to me that something else is causing the failure.

Richard

 

Good to know.

Richard

 

Thanks for this Mike. This is now my theory.

The garage have added the wrong additive to the tank. Perhaps some diesel DPF cleaner or similar and this has settled at the bottom of the tank due to its higher density. That has caused a gradually increasing misfire until the engine won't run at all. I would take a sample of fuel from near an injector and keep it in case in this ends up as a dispute as it can always be analysed later. A full drain down of the tank, filter and all the fuel lines and a refill with fresh fuel will probably sort it although the cat converters might have been damaged.

Richard

 

Plausible.

 

Latest update is that the garage thinks that the timing chain has slipped (the curse of the 5.0L V8s). I know this is a known issue, and now the more I read about it I do think there was a bit of a timing chain rattle which I had not really registered, just assumed it was a usual XKR sound (I have driven XKs previously). Obviously kicking myself now!

Does this sound plausible? I know it is a big an expensive job to get the chain and all the tensioners replaced. I have contacted main dealers and getting a quote from a few independents to see what they reckon the damage will be...

 

Those engines certainly do have a problem with the cam chain tensioner in Range Rover installations so I would not be surprised to see the same issue in Jaguars although I have no personal experience in the latter case. However, I would be very surprised if the slippage was not immediately picked up by the crank and camshaft position sensors rather than simply recording a misfire.

Richard