Picked up the car in mid-December.
Day2 - first misfire, just a couple of hiccoughs really, engine cold.
Day3 - same again. Not too concerned, new engine, it'll settle down...
Day4 - same minor stutter from cold, but then 1hr into the journey - major misfiring, running very rough, amber flashing engine block caution light. Pulled over, engine off, restarted - no warnings, running smoothly. 20mins later same again, stop and restart managed to reset things. Engine then ran fine for the rest of the day (2hrs running).
I returned the car to the dealer and over the next few weeks it was in and out of their hands four times while they tried to trace the fault.
The data log showed a variety of cylinders misfiring at different times, but no clues as to why. They tried swapping and replacing sets of spark pugs and ignition coils, they checked the quality of the fuel in the tank vs the fuel arriving at the cylinders...
At one point the car ran for over 200 miles without a problem and at other times only needed 20 miles before it started misfiring again. It was not proving to be the easiest of faults to pin down!
Land Rover got involved and the investigation continued with their help and advice.
They looked into whether there might be an issue with sensors/wiring on the crankshaft causing the misfire.
After analysing some more test data, they concluded that the car had an intermittent cam sensor fault. So both sensors were replaced.
Total mileage is now 1700. The last 700 miles have been without any misfiring
I won't be totally convinced it's fixed until I've done a couple of thousand trouble free miles - but so far, so good!
The other reason I'm optimistic is that the fuel economy has improved quite a lot post-fix. Previously, on a regular 70 mile A-road route, the best mpg I saw was 27-28. Now, on the same route driven in the same way, it's fairly easy to get 32-33 mpg. So I do wonder if the engine wasn't running correctly before, even when it wasn't misfiring...