Looking for any ideas/input on an issue I've had intermittently over the past year with my low mileage 2014 Xkr vert. This is my third Xk car, and the first time I've run into this issue. I didn't purchase the car new, but have it's history and knew the previous owner and I've owned it for the past five years. Less than 20k miles and is driven monthly ,and kept on a battery maintainer(jag ctek type) in a heated/cooled garage. About a year ago, I had the original battery that came with the car replaced due simply to it being about 10 years old. I realize on a maintainer I could likely get more use, but I'm a preventive maintainer given dealer scheduling, sometime scarcity of parts, etc. Immediately after replacing the battery(dealer used an mtx-49/h8 battery), I had an episode after driving the car in hot weather(90 degrees) about 10 miles whereby the restricted performance mode kicked in at a slow pace red light stop and the car idle got rough. I was able to limp to the side of the street and shut it down. I waited a minute or so and fired it up and the warning cleared, and I continued on to my home about 5 miles without incident. I've had 3 episodes like this only in warm weather. Common denominator was temps were warm(80+), it kicked in after driving about 15 to 20 miles, always after I had stopped and restarted the car once or twice, and lastly always occurred when I slowed down or had stopped for a light, to enter garage, etc. I've never had any issues with starting the car under either battery, and the car has pretty much ran flawlessly for five years.

I took it to my dealer after the first two incidents. There was no issue driving it over there, approx. 12 miles give or take. It ran fine, and they could not replicate the fault codes. It showed p-2105, p-2135 and p061a-29 which I understand are related to the throttle metering system. What's hard to understand is how it clears itself so quickly if there was an issue with the throttle body, etc. I'm not experienced enough to know for sure if a small leak etc could remedy itself in that system after sitting for a minute, but my first inclination given the car ran flawlessly for almost four years and this popped up immediately after changing the original battery out was to suspect the battery. I've had other cars with defective batteries that caused issues when up and running, but honestly i'm gonna get some independent opinions. Has anyone had similar experience or have any ideas/input? thx in advance.

 

Don't guess, get the Diagnostic Trouble Codes and troubleshoot according to the steps in the Workshop Manual.

Your dealer should have done this but, with many Jaguar dealers no longer servicing X150 models, who knows if they still have the tools and competent technicians to do so?

I agree with your decision to take your 2014 XKR to an Indy mechanic for diagnosis. Try to find a technician previously employed by a Jaguar dealer.

Good luck, and keep us informed.

 

Will do. This is my third Xk car, and from reading the threads I guess I've been lucky as the first couple were pretty bullet proof. I agree the dealers once you get past the model being mfg anymore become somewhat lost and useless as a resource. Hopefully the independents still have some committed resources. Does anyone know on the late xkr's 13-15 if they have an auxiliary battery as well as the main battery? I noticed when I had the original replaced a year ago they only replaced the main battery, but I thought cars with start/stop buttons all had a second battery.

 

Just one battery.

 

Thanks.

 

I would check if the electric fan in front of the radiator works. If not the car, could go into a heat range that causes your "limp home mode".
I run a digital coolant temp gauge, off of the OBD2 port.

 

Having had many really old cars (120 years or so the oldest) this is a well known problem on them: fuel vaporisation in the fuel supply line. When it happens, it is a really hot day, the engine has had a hot-soak period turned off after a good run, then restarted, stopped at a red light etc. In the old cars that don't get used very often, it is made for likely bu the fact that fuel manufacturers change their recipe winter-to-summer; the mix they sell you in winter has a lower boiling point (hence better vaporisation in the carb). So if the tank was filled in, say February and the car not used again until June, the winter fuel vaporises more easily than it is needed to in Summer.

My 2008 XK Convertible has done it once or twice, under identical conditions. Knowing what it feels like, I have recognised it. The solution is to fill the tank full with Summer fuel ASAP, open the bonnet and allow everything to cool down somewhat before restarting. The error codes you quoted seem to confirm something like this, I think?

If I am right about yours (and I am sure I am about mine) it is nothing to worry about. I (You?) could fit the SC louvres to the bonnet to give a little lower under bonnet temperature, but I can't be bothered; they are fitted to SC models for a genuine reason, not just swank!

 

My 2007 XK Convertible suffers every spring with left over winter gas. In my case it’s the hard starting within 1/2 hour after a drive. Maybe lucky, but I’ve never had a restricted performance issue.

 

Thx guys, good point. I'll add that to my list of items to check. Do any of you use fuel additives or treatments?

 

Nope.

 

The fuel vapor issue is interesting. The only thing I've had to replace on that car was the gas cap. Almost from the day I got it, I would periodically get warnings with the fuel cap not being tightened even though it was. Eventually, the dealer replaced the cap, and it has been pretty good since. I haven't had but maybe one warning since this restricted performance issue arose on a limited basis in heat about a year ago. The other interesting thing now that you mention the fuel vapor is that the car is kept year round in a garage that is pretty much heated and cooled. It is under my home, and stays between probably 55 and 70 degrees year round. On these hot summer days, the car is coming out of an environment which is cool, and then is getting heated up tremendously. I'm guessing that would increase the risk of vapor issues from a laymen's perspective?