A failing or failed crankshaft posn sensor doesn't trigger any DTCs. The only way to prove it is to monitor its live values to see if it is triggering at all or if it stops after triggering on those occasions where it initially tried to start. Proof can be obtained without going to the trouble and expense of replacing the sensor.

So, is the oil level OK, and does it start with the top turbo hoses disconnected from the engine?

I presumed the guys who looked at it would have done all those basic checks... maybe it will be an easy fix after all... looking forward to seeing what it is...

Kev, please let us know what it was when it gets fixed, a lot come on here, display some symptoms and then we never hear from them again... Pete
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I certain will, Pete.

It’s a bug bare of mine that when you find an old post frequently the resolution is completely absent !

(Yes, all the “basic” checks have been done, and codes read. Oil level is fine, new fuel filter, new fuel pump, new fuel, rail pressure good, clean air filter, motor is pulling in air.

Compression not tested, what would cause loss across all cylinders without other obvious symptoms ?)

Mikey wrote:

So, is the oil level OK, and does it start with the top turbo hoses disconnected from the engine?

There will be a bit of an induction roar but not that loud, the exhaust will remain as it is...

Do you know if the initial guys checked/changed the camshaft and/or crankshaft sensor..??

A jumped cam chain could reduce compression to below the starting threshold but would run as you described until switched off, then the lack of inertia and heat would mean a no start scenario....

It's total guess work though, hopefully it will get sorted tomorrow...  Pete
I now have permission from the boss to use Y.O.L.O. Enjoy life
__________________________________________________
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@Kevhdkent, I don't know if you've seen many of Mikey's posts on here and other LR forums buy he fixes these for a living.
I don't know him and I've never met him but he is one of a very small group of posters on here who's advice I would follow without hesitation.
I hope this doesn't sound disrespectful to any other posters but I'm sure that we all recognise that there are some contributors on here whose knowledge and experience is staggering

Thanks for the advice Cass.

Well, my mechanic has walked away as has the auto electrician.
The 2 specialist garages, one diesel, one diagnostic, near me are booked to Xmas.
So it looks like yours truly will be reading up and getting the spanners out !

Not the first time, but nothing with the sophisticated electronics of the RR 🤞

MIKEY !!!

We are trying to confirm/eliminate turbos as the failure

When they fail, they fill the whole induction system with oil, blocking the air intakes. By removing the top hoses, you bypass any oil in the system, allowing fresh (though unfiltered) air into the engine. If it starts and runs, albeit, probably rough, then the next step is to check the turbos. Also the reason for checking the oil level

If it still won't start, loosen off both the EGR pipes at the back of thenengine, where they attach to the coolers.
I have seen in the past, the turbo has essentially blocked the exhaust, stopping any waste exhaust gasses escaping the cylinders, and choking the engine through lack of oxygen

If it were a fuel pressure issue, a code would be logged.
If it were a timing issue, codes would be logged
Turbo failures do not always log codes, so its back to basics

Hi Mikey,

I will have to ask you to excuse my ignorance.
(Ask be about a motorcycle, but turbo’s & sensors 🤷‍♂️)

I have removed the hoses direct off the throttle bodies.
There appears slight oily residue one, the other is clean.
Both throttle gate valves are full open (which I did not expect for starting)
With ignition on the gates do not react to the throttle pedal (again not what I expected)
When ignition turned off each gate shuts then immediately returns to the full open position.
Put the hoses back on and releasing the other end at the front or the car and placing both palms of my hands over the open ends, the hoses collapse right down to the throttle bodies suggesting plenty of induction draw.

Does that description suggest or eliminate anything ?

(ps when the hoses are off the throttle bodies still non starter)

The butterflies are only used to increase exhaust gas recirculation by blocking fresh air when the ecm detects that more exhaust gasses should be ingested and are fully open at all other times.

Kevhdkent wrote:

Put the hoses back on and releasing the other end at the front or the car and placing both palms of my hands over the open ends, the hoses collapse right down to the throttle bodies suggesting plenty of induction draw.

Does that description suggest or eliminate anything ?

Kevhdkent wrote:

(ps when the hoses are off the throttle bodies still non starter)

AJGalaxy2012 wrote:

Kevhdkent wrote:

Put the hoses back on and releasing the other end at the front or the car and placing both palms of my hands over the open ends, the hoses collapse right down to the throttle bodies suggesting plenty of induction draw.

Does that description suggest or eliminate anything ?

The fact you have induction and it doest fire with easystart points to total loss of compression IMHO. Have you done a compression test? does your hand get pushed off the exhausts when cranking i.e. are there gases being pumped out?