Hi All,

Running out of ideas and wondering if any of you could point me in the right direction?

I have only ever suffered the restricted performance issue on long runs - and only when I go to my mothers house 125 miles away.

The first time I experienced it was the first time I drove the XKR there, during weather Noah would have been at home in. After creating an enormous bow-wave going through a puddle it came on. When I got it home and connected my OBDII reader it came up with a inter cooler pump failure, but seeing as everything had dried out the message had gone and the engine was running fine I assumed it was to do with the torrential rain.

Since then the car has been fine in every circumstance except for when I come home from my mum's - it is very very odd.

Going there is ok, it blasts up the motorways and fast A roads like a dream, but every time I come home I get the Restricted Performance message - at the same place each time.

The journey goes - leave mums house and down 15 miles of country roads (bit narrow and twisty, all under 60), then onto fast A roads (mostly 80-120) for 60 miles, then onto busy motorway (70+ ish) for 50 miles. Problem happens when I get 20 miles along the motorway and come into an 8 mile stretch of roadworks with a 50 speed limit and Average Speed Enforcement Cameras everywhere. Half way into the roadworks the message comes on. Happened 8 times this year - same spot.

When I get it home, I connect the OBDII and there are no codes. Switch the car on and all works fine, no messages - just 1111.

I looked at the car history and see that the intercooler pump was changed 2 years (8,000 miles ago), and last month I had the water pump, thermostat and filler tank replaced due to a coolant leak spotted at the MOT - coolant level is OK now - it was a micro leak anyway, lost a cup of coolant every 1000 miles previously.

Any diagnostic suggestions welcome.

Thank you.

Neil

 

It's always the same spot? I was going to suggest you carry the OBD II and connect it when you get the message and jot down the codes, but. IF it's the same spot, I'm starting to think there maybe electromagnetic surges in that area that your cat may be picking up on.

Try this to confirm: Drive an equally long voyage with a return trip in a different direction. Instead of going to your mum's say in Wales (you didn't specify), drive to Cardiff instead. Make sure not to take any overlapping roads between the two routs. If the phenomena doesn't happen in the equally long trip to a different place then you can confirm your hypothesis that there is something wrong with that area. If it does happen, create a new hypothesis, conduct more testing and analyze the results.

 

Plug in your code reader before you begin your trip and drive it as always. When you get home check your code reader and see what came up. It is hard to say what is going on without the codes or a specific circumstances. Then post any codes and we will try to help.

 

Next time I do a long run I'll plug it in and see what it says. Thanks for the advice

 

Being a car owner that's always relied on my mechanics, how does one purchase a code reader?

 

https://www.jaguarforums.com/forum/g...oved-**-33347/

That link will take you to a list of approved scanners. You can buy on line or in stores. Welcome to the forum.

 

A long shot from someone with no Jag experience - but is there a significant elevation change?

 

My experience with these cars has been that big elevation changes don't affect it at all. On the other hand, visiting the Arecibo Observatory, home to the biggest radio telescope in the world, has caused me a Restricted Performance message. As soon as I left the area the message disappeared. That happened about a year ago.

 

Here are screenshots from the OBD2 App. Seems the app recommends plugs and a coil?

 

On my long trips up to Scotland about 1000 miles in the car will go into restricted performance mode and I get a gearbox fault. Turning the engine off and on again fixes it and taking the intake housing off and back on again fixes it for some reason. I have since cleaned the MAF sensor and throttle body a lot but I haven't done a 1000 miles since then so I can't tell if it's been fixed yet. The temp sensor likes to break as well and reads the coolant as overheating but this can be fixed by turning the car off and on again. I have already replaced the temp sensor once I don't want to do it again. I think it's more likely something else is wrong there, the OBDII reader tells be the coolant temps are fine so it's OK. It's just annoying because it will do it after 1000 odd miles and then every time I reset the car it does it ever 10 or so miles which is annoying to try and reset the car every 10 miles when all I want to do is drive. My OBDII won't read the codes for these problems for some reason but sometimes it does. I don't get it, but I do remember once I got my codes read and one of the things read 3-4 gearbox fault or something like that. I think it was an old code though because the previous owner had changed the transmission oil. These cars can be finicky sometimes.

 

8 year old thread. Perhaps best to start a new one...