I honestly have no clue but mechanics way smarter then me are unsure considering there are no codes!!

2012 XKR. No tune regular oil changes. Went to bed Thursday night after driving my woman to work - 2 hrs of freeway driving for the day… coolant level max no overheating situation. Everything fine. Woke up Friday to horrible sounding vibrating clunky engine. Gas smell coming out back exhaust. Was able to hook up scanner showing multiple misfires on multiple cylinders via live data but no misfire or engine codes whatsoever…. I’m at a loss here how an engine can vibrate, sound, and function so badly yet no freakin codes?!?

Possible clue… maybe not. For a long time I got a tick in my engine - always was told noisy fuel injectors…. Maybe? Maybe not.

open to suggestions initially I thought it was supercharger because no misfire codes. It is misfiring and on multiple cylinders

that horrible noise at startup just makes me think mechanical… camshaft?….. engine filter has never had any metal bits ever in it though 🤷🏻

 

 

 

Gas smell coming out back exhaust. Was able to hook up scanner showing multiple misfires on multiple cylinders via live data but no misfire or engine codes whatsoever…

Possible clue… maybe not. For a long time I got a tick in my engine - always was told noisy fuel injectors…. Maybe? Maybe not.

How many, which cylinders misfiring, (Multiple)? Bank 1 or 2, or both??

Gas smell, overfueling, injector(s) sticking? Have you Run to a very low tank, or refilled recently?
or the timing is out because the chain tensioner is worn.

Tick from engine, chain tensioner loose, timing chain slapping/slipped etc?

More investigates required.

Would not say camshafts failed, but may be moved, or timed incorrectly now because of the tensioner wear! or injector(s) issue.

 

Unless you have had the chain tensioners replaced, I would guess that it is the classic Jaguar 5.0 tensioner failure. If it is, the cam chain will have jumped on the sprockets and the amount of damage will relate to how many teeth have jumped. ☹

You'll need to access the top of the chain at the front of the engine by removing the cam cover/s. You may be able to access the top of the chain sufficiently through the oil filler if it's that side that's slipped. If there is any play in the chain, you have the answer.

Richard

 

My money is on the timing chains having become so stretched/loose that the chains slipped at least two cog teeth, and the 'orrible racket I can hear on those vids is the sound of pistons hitting valves.
If that is the case then the engine is probably toast.

 

As the 5.0 is an interference engine, if the chain tensioners fails I wouldn't be continually starting and stopping the motor, there is a very high risk of lunching the engine.

 

I know what you’re saying - I did ask the dealership if it was ok to start and check. They said if it’s serious like a main bearing or god forbid timing chain - it won’t matter damage was done the minute it slipped…aka game over. Not sure maybe it slipped more?!

I think you all are painfully correct. Once I knew there are indeed multiple misfires on what I think may be both banks…. With that noise it’s not simple.
misfires if I recall correctly were oddly 3,4,7,8? That’s both banks.

i don’t understand why I don’t have any engine management codes at all - nothing …wild. That doesn’t matter either the damage is done.

At 30k miles despite 100% failure the chain didn’t slip just slapped at startup. So everything was replaced anew.

 

So did they replace with the updated Tensioner arm? or the old original type.

30K -118K =88k so about time for an original tensioner ar to go again.

Bad news if the new type has failed.

 

new type. Gutted.

 

I had similar symptoms with a stuck fuel injector. Misfire codes, smell of gas (gas actually was dripping out of the pipe in front of the cat.

 

You'll have similar symptoms with failed injectors. Video sounds like knock. Have a look inside the oil fill and you'll see the chain and can check tension there.

EDIT: You said no DTCs, how are you reading them?

 

I got a obd code reader. It’s picking up all kinds of codes but nothing from the engine.

 

What make and model reader? Any catalyst DTCs? That would confirm fuel being dumped into the exhaust.

 

iCarsoft 3.0 for Landrover/Jaguar. No codes for anything under engine despite live data showing backfires. No check engine light on dash. Nothing so when it first started I wanted to listen to it not know I’m detting my engine 😞😭

 

As said above, if it's the chain, the engine's likely done, so it doesn't matter if you run it. My vote's the injectors because they fail too and cause knocking. The engine can be run safely as the risk of damage from a bad injector's relatively low. I'm not familiar with your tool but SDD can run an injector routine to test the injectors. I know because I just had this happen to me on a 2015.

 

Those of us who have had stuck injectors, and it has happened to my car either two or three times in the 213,000 miles on my car would swear the engine was "toast" by the amount of smoke, unburnt fuel exiting the exhaust and the extremely severe misfire. But each time it has happened to me, a quick tow to my mechanic, replacement of either the bank of injectors or in one case the replacement of a single injector solved the problem immediately. I would bet my bottom dollar that you've got a bad fuel injector that is easily solved. It's not the cheapest repair you'll ever see but beats tossing a wonderful car out.

 

Shouldn't warning on dash or error codes pop up well before something catastrophic failure occurs? Just my $0.02c worth.

 

Good to know but did you have that knocking noise?!

 

I've yet to see any Jag or Rover provide DTCs or any other diagnostic warnings in the cluster, would be nice if they would. At best all I've seeing is the engine MIL which passively prompts you to connect an OBD scanner, and even that doesn't always happen.