2005 VDP 4.2 no charger....


Hi All,
Around 3-4 weeks ago car had a complete replacement of thermostat housing. At the same time, there was no-start that developed.
Engine was "flooded" and the mechanic had to take out the plugs to dry it out. when I picked it up -> it was running like a swiss watch.
This is my wife's daily driver - she drove it for ~400miles. Couple days ago I asked if all is fine and she said it was maybe a little bit rough (haha).
It seems completely misfiring ("little" he he). At that point I do not know how many miles and when it developed but <400miles. Painful rough idle cold and warm. At that point multiple DTCs.
I reset the codes and it immediately complained about too rich mix at the bank2. Took it for a ride and restricted performance >=2000rpm shows up and when the rpms drops, it goes away. Took it to my jag mechanic but he is booked until next week.
after reset only 2 main codes:
a) P2099 - post catalyst fuel system too rich bank2
b) cylinder 8 misfire

just grabbed a new ignition coil at advance auto parts.
Does it seem like a coil at cylinder8??? It is super rough, cold or warm

 

Wrong group

 

Hi memento84,

I have moved your thread from the forum for the X308 to the forum for the X350, which is the Jaguar factory project code for your wife's 2005 VDP.

The rich running reported by the Bank 2 oxygen sensor is probably due to unburned fuel in the exhaust due to the misfire in cylinder 8. It is quite possible that the misfire is due to a failed ignition coil, but it could also be due to damaged coil wiring, a fouled spark plug, oil on the spark plug threads, a leaking fuel injector, low cylinder compression, etc.

A quick test is to swap the cylinder 8 coil with the coil in cylinder 2. Cylinder 8 is the one closest to the firewall on the left side of the engine (as viewed from the driver's seat). Cylinder 2 is the forwardmost cylinder in the same left bank. If, after swapping the coils, the misfire moves to cylinder 2, then you know the coil is bad.

If the misfire doesn't move, the cause is something else. While you have the coil out of cylinder 8, inspect the coil wiring harness for any damage. Then use a small mirror and lamp to look down into the spark plug tube. Oil on the spark plug from a leaking camshaft cover spark plug tube can seep down the threads of the plug, creating high resistance in the ground path for spark, causing misfires.

Unfortunately, cylinder 8 is the most difficult one to access. I typically use a spark plug socket with an integral extension about 4 inches long, then a universal joint, then a long extension so I can work my ratchet up away from the windshield cowl/drip tray and other obstructions.

Cheers,

Don

 

I think your best bet would be to swap #8 coil for the one next to it, then clear the code before you start it up. You may have to take the #8 spark plug out to dry it off. Afterwards start it and see if it stays in the same hole or if it moves to the cylinder next to it.

 

Dear all,
Thank You for moving the thread to X350.
Man, what a trip with removing the spark plugs cover I managed with only un-plugging one of the air lines and moving the cover enough, so that I can access cylinder#8 (this was actually lucky, the only cylinder on "driver's" side that You can access without complete disassembly of the air intake (!).
I only replaced the ignition coil and wanted to test it quickly, as I didn't want spend extra time with removal of the spark plug.
It paid off - big blow of smoke from the cylinder (that was normal, as there was a lot of unburnt gas) and the DTC light reset itself immediately.

Question for all of You that know this system - I found out 8 ignition coils that look to be the same and probably same age -> were Delphi's the original ones? Would they last ~100k miles? I paid ~$70 bucks at AAP for some no-name from quest -> ebay has these no-name ~$90 for 8 coils. Should I buy and keep them just in case?

 

The original coils were made by Denso (the Engine Management System is Denso, so all the original sensors and coils are Denso - the OE spark plugs are NGK Iridium). Rock Auto currently stocks Denso coils at under USD $40.00 each.

For several years, Denso coils were not available. During that time, the replacement coils sold by Jaguar dealerships in Jaguar boxes were made by Airtex and were marked FoMoCo (Ford Motor Company). Rock Auto carried the Airtex coils for under USD $40.00 each, and I have used them with good success, but I have not seen those coils available for awhile.

Cheers,

Don

 

From experience - recent - it's a 'dice roll'. They might work fine. Or not.

Set of aftermarket ones for the 2005 4.2 put on about five years back hasn't set a foot wrong, yet.

My last go, coupla months ago, the eBay set threw "misfire 1,3,5,7" for the whole dam' bank I had just installed them onto, and 'immediately' not at ANY miles. (AJ133 5.0 in the Rover this go, not the Jag 4.2, but much the same system)

Lesson learnt, seems wiser to carry one if not two - not a whole set of 8 - of the best genuine OEM you can lay hands on as spares. They aren't prone to mass failure anyway.

Cheap outlay, compared to risking the health of the car and motor you are trying to keep properly powered, not washing its lubricants off the cylinder walls, confusing O2 sensors, damaging costly cat converters with waste of co$tly unburnt fuel.