I have an 2005 xj8l, with 40k on it, just now out of warranty. I have had the car into the dealership twice in the last 2 months for the check engine light coming on. Each time the dealership claims to have cleaned out the injectors and the car is fine. The second time the light came right back on 10 minutes after i left on a friday night. I called to bring it back, but the service advisor told me to see how it drives over the weekend, and call him back on monday. Now i know this probably was not the best idea, but i needed the car, and it seemed to drive fine despite the light. Now it just recently came on again, but the car drives fine, seems to have no issues at all. So over the course of the next 3 times turning it off and on, the light eventually goes away. How concerned should I be on this? Since the car is now out of warrranty, I want to argue that they never fixed it at all in the first place. It does seem to run fine though. I am losing confidence that the dealership even knows what its doing in the first place. Can bad gas cause this kind of thing? I am in the chicago area now and many times i think the gas stations in the city while charging more seem to have crappier gas, vs the suburban stations. I am only basing this on how the car rides after fillups, nothing scientific here lol. Any suggestions on what might be going on here? I can take the car in and post the codes after they run it, but i suspect they will come back with "the car is fine" crap and there is nothing we can do. Thanks for any advice you can offer.

 

The service itself should still be covered under the dealer's 12 month/12k miles warranty. It should be stated on the customer copy of your invoice.

 

Any time a code is stored there is a problem . I bet either a p0105 map code or just a misfire code . Map sensor code can be difficult to replace had one that wud come on every three months was difficult . Also had one for misfires turned out our engineer discovered that it was the octane in the fuel we told our customer to put mid grade in the winter and premium in the summer . Worked out fine

 

Defenitly get them to cover anything

 

I've had my car into the dealership four times for the same problem. Each time the error message was misfire and finally the dealership decided to replace the fuel injectors. It has been 2 weeks since the injectors were replaced and I've had no problems.

The biggest complaint with this car is that a problem is rarely fixed properly the first, second or third time...it takes 3 to 4 visits to properly diagnose and repair. That being said, I know the cars are complicated and that it's not always easy to identify the issue. My warranty runs out in October and I have concerns.

I hope that they cover the repair for you as it sounds like they didn't fix it properly when the car was under warranty.

Cheers,

Steve

 

Thanks all, I also have noticed that when the car is cold and i start it up, it shimmies a bit, nothing major, but just seems off. After its warm it seems fine. I will ask about the codes and bring up the injector replacement as well. I am taking it in on wednesday morning.

 

Unfortunately, replacing the fuel injectors has not solved the problem. My XJ8 returns to the shop on Tuesday. The shimy on mine only appears in very specific conditions (ie. -5 to +10, warm car restarted after cooling for 20 minutes). It isn't a major issue, but I am concerned that whatever small problem is causing this symptom could get worse and end up costing me money once the warranty is done.

 

Do you always buy fuel at the same station or use the same brand exclusively? Have you tried a different brand of fuel? We used to have a lot of cold start issues with misfire on all Jag models and it was usually caused by poor fuel quality. The quality of fuel in my area has improved dramatically in the last 2 years. We rarely get cold start problems any more. That's also the reason the fuel injector cleaning usually improves things for a time until the injectors start to get plugged again. That's also the reason replacing the injectors helps as well, just like cleaning only better as the cleaning will always leave something behind. Trying a different brand of fuel is at least cheap and easy to try.

 

Thanks for the feedback. I don't go to the same place for fuel, but will try one specific high end brand.

I live in Canada so temperatures get much colder (-20) than the -5 to +10 which seems to bring the problem on. If it was a fuel or build up issue in the injectors I would have thought the cold start problems would occur in the colder temperatures as well.

Seems like this problem only appears in the Spring and Fall when temps are in a very specific range. Again, it only appears when I've driven the car, it warms up, and then stop for a short period of time. I know nothing about these cars, but wondered if it could be a sensor issue (ie. engine thinks that it is still hot so doesn't provide as much fuel on start-up)...Maybe I'm just thinking too much of chokes on lawnmowers...

I'll try the fuel idea.

 

I am taking the car in today, so I will make sure to get the codes and post to see what might be going on. I too thought about the gas issue, there are some stations where the car runs really well after a fill up, noticeably so. Has anyone messed with lower quality gas? Like any that are not 93 octane? I also once in a while get a lagging acceleration problem when moving from a stopped point, like at a traffic light.

 

I've had the same problem as have many owners here in the UK. It's a common fault which actually sometimes isn't a real fault as no codes show up. I read somewhere that it could be a blocked breather pipe to the fuel tank, so, as the fuel is used it causes a bit of a vacuum. If that's right or not I'm not sure but next time mine lights up I will check it out.

 

I would hope the technician had checked the temp sensors when you mentioned to them about the specific temperature causing the problem but you never know. Another thing that could cause such a problem would be fuel pressure bleeding down when the car was sitting for its 20 minutes or so. Does the car seem to crank just a little longer than normal when the misfire or rough run happens? Are the codes for all cylinders misfire or just a select 1 or few?

 

The rough running on cold start is possibly a software issue. Just get the dealer to reprogram the adaptations. There is a service bulletin for this problem.

 

I would surely hope that that was the first thing done. It would be a shame to see that Jaguar had paid for thousands of dollars of repairs including new injectors to find out that the software is 3 updates old!!! Maybe I should spend more time thinking like a hack. I do know that if a tech in my shop asked for my help on a car that they couldn't figure out and I found out I was wasting my time on a car that didn't have the correct software there would be a serious bitch slapping to follow.

Perhaps that's why most of my initial posts are asking more questions rather than providing answers.

 

I am always suspicious of mass injector failure at low mileage, this would be unusual. Maybe one could be bad, but it would give a hard misfire at some certain pulse width that would be easy to diagnose. I recently had an injector fail at minimum pulse width only which caused a hard miss at idle but only in neutral or park. Whenever the car was under any load at all, such as being in gear, pulse width went above 3ms, then it worked fine! The injector just flat failed. The only fix was a new one.

 

I took it in today, they did some sort of recall software update that had to do with the transmission. They could not find anything else wrong with the car. I do suspect bad gas might be causing the problems. The car ran totally fine when i was driving it in. I will watch and pay attention to where i am filling up the car.

 

It's not that the injectors fail, it's that they get plugged up. Starting with the x-type in 2002 the newest style injector jaguar is using has atomization holes so small that you need a 10x magnifying glass just to see them. Like I mentioned before, we used to have a lot of problems here in SE MI due to poor fuel quality with higher than allowed sulfur content that would plug the injectors and starting in '06 it would also set special contaminated catalyst codes. i haven't seen any contamination codes in the last 2 years and the number of cold start misfires has declined markedly. there is a bulletin for this though it mentions only some southern states, i wouldn't hold to the states mentiond, it could be a problem anywhere.

 

Ok, so here is what has happened so far. Car runs just fine, smooth, accelerates well, i ran it to 120 when i had the chance. Was sitting in it a few hours later, the check engine light, restricted performance message came right back on. Car however rode fine, no acceleration issues. After turning it off and on a few times light goes off. Dealer told me nothing based on scans. So now at this point I will just monitor it and see how it goes.

 

Technicians have had the car for 2 days and been unable to come to any conclusion. They did find an error code indicating a misfire on cylinder #1. These misfire codes have been present every time the car runs rough, but the cylinder number changes.

They have decided to "reflash" the programming and hope that it is resolved. I still don't understand why the dealership doesn't start with the least expensive solutions first. Prior to this point, we've done many things including the replacement of the fuel injectors.

Anyways, only time will tell.

 

A misfire code moving from cylinder to cylinder on subsequent drive cycles is very likely a software problem. Replacing a fuel injector would be time and money wasted. I might also suggest that the system used to pick and operate the firing sequence may be at fault. This could be caused by a problematic crank position reluctor or bad connection in that harness.