This is a new one, drove the car a few miles(approximately 6,including a long idle/stop for a passing train 15 minutes). I parked to do some shopping, exiting I got a new to me rumble from the rear with shaking/vibration & erratic idle. Had a brief "Restricted Performance" warning that disappeared within seconds. Ran smoothly back to the house about a mile away.

Codes : P1000(incomplete testing cycle),P0300(cylinder misfire),P1316

Only thing done differently was last night, I used some fuel treatment(a different brand than the one I use every 6-8 monthes) on a full tank. The battery is new,fully charged & kept on a maintainer nightly so we can rule that out, also the O2 sensor was replaced less than 7K miles ago.

Car's given me zero mechanical issues now it waits to do this as I'm about to paint lol. I hope this isn't the harbinger of problems.

Any input's appreciated.

 

Occasionally, when mine would go into RP it would run very rough. Normally, not .. but I would shut off and restart to a everything normal. The few times when I let it run .. it would often stumble. I may have received a code .. but I was doing resets while it was running and did not to check.

I would not worry about it unless you feel something w/o the car in RP mode.

You could have a misbehaving coil ... that will be easy to pinpoint.

 

Everything points to an erratic and inconsistent misfire. This happened right after adding something to the fuel. Jag specifically says to never to use fuel (or oil) additives. Hmmmm.

 

I've been running BG 44K in all my older cars(every 5-8K miles) for years including this & a previous XJ8 with no problems. This time it was STP, lesson learned lol.

 

I listened to Jag and never add anything to the fuel, ever. The car runs perfectly.

Again, Hmmmmm.

 

As an alternative, have some "fun" trying to figure out what's actually wrong. Maybe study sensors etc, fuel trims, and so on. Or see what happens if you ignore it and maybe damage a catalyst.

 

Going to top it off with fresh fuel(to further dilute the STP)& see if it resurfaces.

 

STP is ****, cheap company. But I had this problem couple months ago, It is a bad coil and will get worse. I had to replace 2 in the past couple months. https://www.jaguarforums.com/forum/x...rmance-171350/

 

Yeah I'm a BG zealot, just last night I had an associate fill it up & these things happen w/ the help lol.

If I have do one coil, I'll do them all.

 

Here is a discount I found, the coil from the dealer is $125 but from here it is cheap, i have it on my car and no problem. Comes with one year warranty and got it in 3 days. http://www.ebay.com/itm/JAGUAR-OEM-0...vxp=mtr]JAGUAR OEM 00-03 XJ8-Ignition Coil LNE1510AB |

 

Yeah I just pulled the code log it was showing misfire on every coil, I think it's definitely STP related. Going to do the top off w/ fresh fuel.

I click your E-Bay link it takes me to a vig link shopping page maybe your original link is flawed or too long .

 

JAGUAR OEM 00-03 XJ8-Ignition Coil LNE1510AB
Hope this works.

 

Charles,

Had an identical problem with my VDP. All signs pointed to a bad coil.

Ordered these: 8pcs Ignition Coils For 96-03 Jaguar Vanden Plas XJ8 XJR XKR XK8 4.0L V8

and it's been good ever since. Good luck!

 

when you top it off add the BG 44K to off set the STP crap....or is that too much....?

 

Just going to go straight fuel nothing additional, even if it clears up I'm still going to do the coils, that's just good practice.

 

Did you not say it is running fine now?

As I said -- mine would run rough when the car entered RP. Just from being in RP.

.. the knock sensors will often give codes for a whole bank .. you can't rely on codes after running rough for a while. Clear and recheck at the first indication of a problem.

Don't throw parts at cars -- Coils do fail ..... but it's rare to have to replace all. The only time would be if a particular design was found to have a defect. -- VW/Porsche had a plastic problem that caused all the coils to fail. Jaguar does not have this issue.

You should not need any additive -- unless you dumped in way too much, my guess is it's not related. Gasoline is full of various additives - save your $$

 

One of my coils failed last week and actually melted, which caused her to run only on 7 cylinders. This was a 4 pin coil, which I understand are prone to failure occasionally. It's the first time it happened to me, but a quick google search showed it's not uncommon across the JLR range that shared our engine platform.

 

I'm not one for running off to the parts department as soon as I see a DTC.

You got a random misfire soon after using a different fuel additive. Not even getting into the debate about additives, this in itself is a change which is a possible cause of the code and RP.

I'd run the fuel down, clear the codes (the P1000 shows you'd done this recently for some unexplained reason ......?) and see if the code resets.

Codes often set just because a sensor goes temporarily out of range. They don't always indicate a component failure.

Graham

 

Well turns out the fuel station I use has had several complaints over the same time frame, so compromised gas is the most probable culprit.

 

I love threads with a beginning and an end.