My 2007 went back to Jaguar Engineering (JLR - not a dealer) when still under warranty. After repeatedly failing to diagnose the cause of the MIL triggering for the original owner, the dealer (GUY SALMON JAGUAR in MAIDSTONE) sent the car to Jaguar Engineering in Daventry for investigation. A smoke test revealed a small hole in the cylinder head. This resulted in a slight leak causing lean mixture and triggering the MIL. A Jaguar approved repair was carried out on the cylinder head and there was no repetition of the problem during the PO's or my ownership.

An unusual problem and a very unusual action by JLR but it shows you may have a possible cause beyond the 'regular' fixes suggested in the DTC listing.

Graham

 

@GGG Thank you - need to figure out when to go that route - thinking at least pull right side injectors and test - if after that there are stil issues then yeah probably something more mechanical.
Thanks for the insight there...

 

OK - so
1. Engine Flushes
2. Replaced ignition coils
3. ALL new Spark Plugs
3. replaced the VVT Solenoids - Fixed random misfires on right side 1,3,5,and 7 still on 2,4,6,8
4. pulled top end found a lot of oil in intake runners - pulled original PCV - gooey and stuck replaced that - manifold vacuum went from 16.7 mhg to 11.4 mHg
5. Cleaned all oil from intake runners , gently cleaned valve stems some had some build up on them
6. ultrasonic wash and reverse flush of injectors - put all injectors back after thorough testing
7. All back together - engine cold and warm purrs - does a good pull up to 4500 RPM then misfires on 2,4,6,8
The Super Charger sounds much better, the acceleration has improved greatly, but the misfires only come in at 4500 RPM
The indication is its timing - Going to pull the VVT solenoid and verify its not plugged up Also further inspect the VVT for any loose or non working parts.
Also found out from owner who performed the test driving its much better at idle and acceleration - also showed on the ODBII while driving. O2 sensors working and fuel trims much better.
As an aside I am not getting the P0430 as much now - getting the misfires first so its on the right track.
All in, the car injectors were part of the problem, the PCV a contributing factor, but The Timing I believe is what started this downward spiral.
I suspect the VVT might be damaged, but hoping its just a clogged oil passage because its somewhat intermittent.
Getting close to resolving the mechanical issues on the low mileage XKR.

 

I've copied this thread to X150 forum as the technical discussion is best carried on there. Here's the link to the copy thread:
https://www.jaguarforums.com/forum/x...friend-254302/

I removed the 'welcome' posts as they don't add to the discussion.

Please continue the topic in the new X150 thread.

Graham