Not good news.

I’ve attached images of the summary they provided.

Misfire on cylinder 6 with a noise in the upper end of the engine. They recommended taking it to the dealer to further diagnose/address.

Anyone had a similar issue? How screwed am I here?

 

The suggestion that aftermarket tuning may be a factor in this case is important. Are you aware of the full history of this car, that is, have there been alterations made?

 

I was not aware of a tune or any other modifications
on the car when I purchased it. Seller did not make it known there was one if there is. It was a single owner since new, I believe leased, and was his wife’s car so find it somewhat surprising it would have been tuned at some point.

It’s a 2015 R if that is of any relevance since I don’t think I mentioned that yet.

*Also, I’ve only owned it about 3-4 months now.

 

I suspect it’s nothing more than a bad injector (or two). The service technician probably is not familiar with F types and how noisy the engine can be at startup. Besides, a mechanical issue will cause the engine to remain running rough contrary to your observation of an occasionally smoother running motor.

 

So you’re saying maybe I should stop my ravenous search for the best extended warranty option I can find and just take it into the dealer to have them assess?

 

+1
It doesn't sound serious yet, you have classic symptoms of normal wear and tear items intermittently failing: an injector, ignition coil, or spark plug. None are expensive and are meant to be serviced and replaced at the specified intervals. A misfire is not an uncommon thing, that's what happens when you don't have consistent fuel or spark. The injector can clog or fail to open intermittently with age. A coil is like a capacitor that stores energy over time sufficient to fire the plug when directed. As plugs age, their gap increases which requires more energy and may put undue demand on the coil, plus the coils weaken with age making it harder to fire on time, every time. Especially with increasing RPM as you described which decreases time between sparks to build energy.

 

I'm hoping it is something along those lines. I called another shop that was recommended who works on JLR a fair amount. He said based on what I was describing and the mileage (68k) he suspects it could be the timing chain.

As I mentioned, I am not mechanically inclined sadly. Are injectors, ignition coils and/or spark plugs something that can be done in my garage or would they be better left to a professional?

Also, if there is anyone in the Austin, TX area who is mechanically inclined that may want take a look please do let me know.

 

Since there is a cylinder # associated with the misfire, the timing chain seems less likely to me.

If I was going to DIY it, I would start with swapping the #5 and #6 ignition coils, clearing the codes, then seeing if you get a #5 misfire. If so, buy a new coil and you're done. Its a free test to swap parts between cylinders and has a reasonable enough probability of success.

Next I'd take a look at the #6 plug to see if it looks healthy. Comparing to the #5 if needed. Again you could swap 5 and 6 to see if the misfire moves to #5. Again free test.

If those don't work, replacing the injector is definitely DIY able and not too costly. Again the swap technique could isolate the issue. Another free test but a little more involved since the fuel rail might need to come off. I'd have to see how acess is.

I've done many of the above, but never on an F. I'll take a look at mine to see how much of a PITA plug and injector access is. The good news is the #6 is the second cylinder from the front on the drivers side.

Maybe someone has changed their plugs who can chime in?

 

Thanks @RacerX

You may not have seen my earlier post but supposedly the shop I dropped it off to this morning to diagnose swapped the plug and coil and still got a misfire on cylinder 6. But definitely hoping it could still be an injector or some other relatively simple/inexpensive fix compared to something like the timing chain.

At this point I may bite the bullet and take it into the dealer since they should theoretically be the most qualified to diagnose what the issue is. Anything other than the plug / coil swap test may be beyond my pay grade.

 

Latest update:

Called the JLR dealer here in Austin this morning. Was told I could drop it off but would be 8-12 days before they could diagnose (?) and it would be until April when I could get a loaner vehicle at the same time

Since I'm not looking to wait 2+ weeks just to have the issue diagnosed, I'll be taking it to the other shop I contacted yesterday early next week to have them take a look.

Will update once I have more info.

Thanks for the help from everyone thus far!

 

Is the car still under warranty (I don't know what year your car is)?

 

No, it's a 2015 with 68k miles.

 

Ok. The only reason I was going to bring that up is that JLR could claim an independent shop caused damage trying to diagnose the car. If it's out of warranty, then it won't really matter. I'm sure there are plenty of independent shops in your area that know Jaguars.

 

It looks like your car has an ECU remap. It also looks like you switched to (likely) colder spark plugs. The cats on the F-Type tend to run hot and that triggers a rich A/F mixture to help the cats cool down. The last two cylinders are usually the ones most affected by overheating (last two towards the firewall). What other mods have you done to the car?

 

I've only owned it for about 3-4 months and haven't done any modifications to it. I was unaware there was any kind of tune on it and was also unaware there were non-standard plugs installed until yesterday.

Will definitely be planning to put the tune/mapping back to stock along with the spark plugs. I'll also try to reach out to the previous (and only other) owner to see if there are any other surprises I should be aware of.

 

The non standard plugs sound like a tune since mileage isn't super high to warrant a plug change. They may have flashed it back but left the colder plugs, too much of a PITA to reverse. Great news if so, easy fix.

I think this fits yor symptoms since the misfires were happpening at high rpm, which seems more likely to be spark than fuel, since less time between sparks stresses the coil more, but probably doesn't impact the injectors as much. A non-standard spark plug gap could require more energy and occasionally misfire. That explains the random misfires too. IOWs the coils are ok, but the spark gap they need to close in all cylinders is harder than it should be to overcome. #6 might have the largest plug gap, so switching only the coil wasn't enough to switch the problem to #5.

Another possibility is the car is still tuned and just needs new plugs. Most tuners recommend new plugs every 20-30K miles with a higher performance/boost tune.

Make sure your dude gaps each plug to spec with a feeler guage, by hand. OEM is never consistent.
​​
Saw this Scotty video in my silly YT recommends today.

 

And before you reverse a tune make sure you have a standard size crank pulley or it will throw a code. If you have a smaller upper SC pulley it will work fine with the stock tune.

 

Thanks @RacerX !

When I drove it from the shop who initially diagnosed it back home approximately 20 miles, I did so very gingerly and the CEL did not come back on. As you and some others have outlined, hopefully since it only comes back after a hard acceleration that's a strong indicator it's something to do with a combination of the plugs, coils and injectors and not something more serious that may remain under any driving conditions.

Was hoping to get it in somewhere else and diagnosed further before the weekend but no such luck.

 

Not sure how much an ‘ear test’ can help in my situation, but all I can do is continue to wait for a shop to be open and able to further diagnose in the meantime so figured it couldn’t hurt to throw this on here.

I decided to add some Seafoam to about a half full tank of gas. I stopped off about 10 minutes later and filled up then proceeded to drive for another 20 minutes or so.

I took it out one more time tonight for a few laps around the neighborhood but didn’t go above 3500 RPM. Still no CEL appearing after having it cleared on Thursday morning and driving another 50 or so miles since.

The video is right after pulling back into the garage. It doesn’t seem to sound great, but I also haven’t ever carefully listened to the engine running previously so don’t have much of a baseline to go off of.

Does this sound off to anyone?

*Couldn't get the video to upload through the site so I've included a Dropbox link to it below:

https://www.dropbox.com/s/n9am03dqai..._0636.mov?dl=0

 

Had similar issues yesterday. I’ll let you know what I find out tomorrow from jaguar.