So my car has been flawless until I actually had to use it this morning to drive to a client meeting. Very odd, it was jerking back and forth at partial throttle, especially at low speeds, unless I used manual gear selecting mode. It threw a CEL on the way home. Any guesses as to what it will be? I find out at my service appointment tomorrow.

 

Based on your description, it appears to be a misfire due to a failing or failed coil unit(s) that may be caused by engine oil seeping into the spark plug well.

Under no circumstances operate the vehicle if the MIL if flashing as damage to the catalytic converter(s) is occurring.

 

Wow thanks for the response. So if that is the case replacing the coil pack should do the trick? Should I be worried about a more serious problem?

 

Curious on the code it has thrown?....just had same issue on my BMW...needed to replace plug and coil for 2 out of the 6 cyclinders.

 

well its the coils or its the injectors and fouled plugs caused by some carbon build up

 

Is this the diagnosis from the service shop?

Direct injection engines can experience carbon deposit build up on the back of the valves as fuel is no longer sprayed into the inlet manifold to help keep them clean. There are many variables that can cause the carbon deposits to form, so PCM software mapping is critical for the correct combustion timing to reduce carbon formation.

Heavy carbon deposits on valves may require the cylinder head(s) to be removed for cleaning.

Here is a link to additional information on this forum:
https://www.jaguarforums.com/forum/x...charged-94489/

 

Nice thanks for the input, much appreciated! No flashing CEL so far, just solid after the second key cycle. I am driving it gingerly to the shop tomorrow and I will report back on their findings.

I have always been nervous about carbon fouling on the DI motors I have owned...hoping this one doesn't have issues like the Audis have had.

 

You cannot make a diagnosis of plugs, injectors just by that fault description!!

Could be a million and one things, even a faulty ECU, MAF sensor.....god forbid!!

interestingly i had the same issue on my R. Very specific light throttle when coming down the rev range to low speeds and then an engine judder misfire like between 1500 and 2000 rpm. If i revved out past this point it waz fine and pulled strongly........no warnong lights and been absolutely fine, driving flawlessly.......before i decided to clean my MAF sensors a few days back to get rid of and residual oil from my K&N filters......potential fault one......i also thought to check the oil level........after 20 mins sat on level ground..........add one litre of oil!!!! Added the Ford/Jag recomended 5w 20 oil and all is now good......well today it was at least.....time will tell and just hoping i have not screwed the MAF sensors!!

i now wonder if at low rpm and with low oil the ECU is holding back and limiting the engine until the pressure builds.......just a guess.......worth checking your oil level though buddy.

 

If the MIL is constantly on, be sure the shop working on the vehicle records the DTCs present in the system rather than just deleting them.

Post the DTCs here so forum members can offer more accurate suggestions on causes and remedies.

 

The tech seems pretty bullish on it after I dropped it off. There is an ECU mapping update he said that has fixed some of them but also said that it could be carbon fouling already. I asked him to include the MIL codes on the paperwork at the end so I will keep everyone posted.

 

Got the call, it was MAF sensor related. Sounds like replacing the part is the answer, covered under extended warranty no problem.

I will post up the DTC codes and such when I get the invoice tomorrow.

 

Good to hear it's nothing too serious. Glad you had warranty to cover it.

 

Code was P0101 Mass Air Flow Sensor Fault. Car runs and pulls like a raped ape, better than I ever remember it ha. It never felt super "off" but lately it was a little hesitant on power delivery and that makes more sense. Would have been a $425 fix out of warranty.

 

Oh also, I saw this when I pulled into the dealership to pick up my car this morning...why do they always have to tempt me with awesome upgrades??!?

1 of 30 in the world, 25 stateside. Absolutely stunning presence in person:

 

Thanks for posting back.......both with the results and the GT!!!

HOPE its not my MAF now although they are much cheaper in the UK.....about £100 each.

Still ok after adding a litre of oil.........fingers crossed.

 

WOW Awesome F Type GT....Wonder what BHP is ?
Would want one toooo!...Glad your issue resolved...thanks for posting follow up.

 

Oh Wait....just looked again!!! Not an F....XK!

 

Yeah no problem! Hopefully this post helps someone in the future. Yeah the sensor itself was $223 USD or equivalent to 140 pounds. If I had to source it out of pocket I probably would have scoured the interwebs for a cheaper one. Hopefully the oil addition fixes your issues!

Yeah man I was blown away, I didn't realize how rare the XK-RS GT was until I got home and looked it up. I don't know how you could get rid of that beauty...especially considering he probably took a BEATING on that trade in!