I had the "reduced performance mode" come on. No other error lights showed up on the dash.

I had just filled up the tank with Sunoco 93 octane, I usually use 91 octane, and drove about 20 miles, stooped for a cup of coffee. When I came back to the car, I accidentally set the car alarm on by pushing the head lite button, instaed of the door open button, several times on the remote. I was able to shut it off by unlocking the door with the key and putting the key in the ignition and setting to start. After the alarm stopped, I started the car and everything seemed OK. About 50 yards down the road the reduced power came on, it went out after about 3 miles, then came back on for about 20 miles, then went off and has stayed off for the next 10 miles.

I parked the car for about two hours, restarted and drove home, about 60 miles of driving, without any problems. Is this something that jaguar programmed into the system after the car alarm is activated? Anybody have any ideas.

Bill N
03 XKR

 

My take is that the events are unrelated an coincidental. I would suggest seeing if there are any stored OBDII codes.

If you have no stored codes, and restricted performance occurs again, try to read the OBDII codes while it is in restricted performance mode.

 

I had the RP come on three weeks ago, but I got the RP along with the check engine lite on. The code reader indicated knock sensor. I assumed it was bad gas and refilled with Mobil 91 octane. The RP went away, after about 10 miles, but the engine lite stayed on for about three cycles then cleared. I will have the codes checked today and see if there is one. I am thinking it might be one of the knock sensor going or a intermittent spark plug coil. I have driven the car, since I bought it, over a 1,000 miles and this is the first time I saw this happen. The only thing I did on the engine, before this happened, was change the air filter??? My Jag dealer is having a free "service clinic" next week and I will have them check it out and give me the $$ verdict.

Bill N
03 XKR

 

Might want to check the fuse on your S/C intercooler aux. pump circuit. I don't recall the fuse # but the fuse box is located on the paasenger side engine compartment. I had this happen when climbing hills at freeway speeds and didn't throw any codes. There's a writeup under xk8-xkr FAQ's. Good Luck.

 

Having the same thing happen. This all started about 2 weeks ago when trying to get the A/C to just blow in outside air. Throws a 'restricted performance' and a CEL, lasts a couple of minutes, then clears itself out. Throws a P0327. May not happen for several days, then does it again. Was thinking of doing a 'hard reset' at the battery. As far as fuel I always run premimum BP.

 

might be time to get a new knock sensor installed (or do them in pairs)

There's a good writeup here.

 

Bill my 2000 did the same thing. When I was filling it with fuel I keep trying to add or max it out or top it off. I have always in the past when the pump stops that was it. About 20 miles later stop the car turned of the ignition, removed the gas cap and put back on. Restarted the car and no more restricted performance code. That was about 2k ago. Had an old dodge that did the same thing but it said not to over fill. Jim

 

Thanks for the info. I just went down and checked my gas cap and when I took it off I noticed some condensation on a small section of the rubber gasket that goes around the gas cap. I cleaned the gasket and reseated it. Maybe that will help, but I think my problem is an intermittent knock sensor. I am going to have them checked next week at my Jaguar dealer as they are offering a free service inspection. The last time this RP came up I also had the check engine light come on. The code showed a knock sensor error right bank. I did not had the the engine lite come on this time, so I did not have the error code checked yet. The knock sensors are not expensive for my car so if there is a hint they are bad I will have them replaced or maybe do it my self.

 

Mat

Thanks for the info. I went to the site but none of the pictures were shown. Do you know if a marginal sensor would always give both a "check engine lite" and the "RP message" or just give an RP message.

The last time this happened I got both an RP and check engine lite and assumed the knock sensor detected bad gas as it should do. This time I just got the RP message. As I was driving It came on then went out then came on again then went out.

I have driven the car about 60 miles since this happened, without any problem, but once these things happen they usually don't fix themselves. I assumed the first time this happened was due to bad gas, but now I think a sensor is going.

The Jag dealer told me, if you steam clean the engine or if these knock sensors get wet, vis a hose break or leak, they will need to be replaced. I have only had the car for about three months so I don't know if the previous owner steamed cleaned the engine or had a hose replacement.

Bill N

 

the electrical connectors under the bonnet are very sensitive to water ingress, nobody washes their engines with just a hose or pressure washer, unless they baggie all of the connectors first. The throttle body connector is the worst, it seems.

Swap the knock sensor with the other side, see if the next code that comes up follows it. Cleaning all of the connectors while at it will only be beneficial also. best of luck!

 

Matt

I assume swapping them out is a pretty big job on a supercharged engine. If I had the expertise I would do it my self, but after seeing what has to be taken apart to get to them I chickened out. I have been driving around and the RP message has not shown up. I should know whats going on this Thursday when I take it in for the Jaguar free service clinic. Can you believe Jaguar is doing something for FREE!!! We all know they will find something that needs repaired or replaced.

Bill N

 

...or they could just be trying to build relationships with jaguar owners in their geographic area, owners who'll think 'warmly' of the service dept the next time something happens to their car or it needs normal work performed (where one might go independent w/o even thinking about it). My dealership and I have exchanged 'no charge' services for several return service appointments for specialized work (such as alignments, computer updates, and other complex maintenance I'm not willing to tackle myself). It worked on me, and this clinic, who's cost will surely be minimal in time and refreshments, could bear fruit long after its conclusion. Its good marketing if done well.

 

You are right Matt, it is good public and marketing relationships with their customer base. I am sure they will find something that needs attention either now or later down the road. I have been using this dealership for all my Jaguar work that I can't do myself and they have been very good but expensive, especially for parts. There is one other Jaguar repair facility near me and they have sponsored several of
our Club meets at their garage. A lot of our members use them for repairs and highly recommend both them and the Jaguar dealership.

Bill N

 

I just got back from my Jag Dealers service clinic. All is well with my XKR. The last RP messages I got were not in the computer and I have not got any since. I guess time will tell. They did recommend that I change my brake and power steering fluid?? I only have 50k miles on the car. I will probably have that taken care of before I store the car for winter.

Bill N
03 XKR

 

I wash the engine compartment ALL THE TIME on my XJR... If you were not aware, there is a product called "liquid electrical tape" that I have placed on all wires leading into connectors. You can get this at any boating store.
I hate a dirty engine compartment.
FWIW

 

yup, brake and power steering fluid change is a safe, preventative item. At 50k, you're more than overdue.

 

Hey Matt, thanks for the advise. I have scheduled the fluids to be changed next week.

Bill N
03 XKR

 

Well it happened again on my way to the big British Car Festival in Lenox, MA. I stopped and filled the tank, about 10 miles from the hotel. Checked in the hotel and left for the meet about an hour later. I turned the key and as soon as the car started I got the RP message. It stayed on and I also got a engine lite this time. We went to the meet and drove through town with the rest of the cars, RP and engine lite still on.

We went back to town for dinner, lite and RP message still on. After about 4 hours came back to the car and started it, no RP, but engine lite still on. The next day after about three cycles the engine lite went out. The car is back to normal now.

The Jag is scheduled to go in for service this Tuesday and maybe they will find something this time because the engine lite did go on this time.
The problem seems to occur only when I fill up the tank drive for about 10 miles stop for a 1 hour break, then when I restart it I get this problem.

Any ideas from you guys would be help full. By the way my XKR won first place in the Peoples Choice competition. Yahoo, if I could only get this RP problem fixed, I would be a happy man.

Bill N
03 XKR vert

 

Bill, I suggest keeping the scanner with you, or get a Bluetooth OBD and use torque for android. You have to be able to see the codes when your RP comes on, the only time I had the privelege of receiving that message, I was running too lean, long term fuel trims were over the max threshold (15% IIRC) but it self clears if the condition does not reoccur for another two drive cycles. My eventual cause was unmeasured air leaks over various hoses and o-rings at Norma connectors. The knock sensor code you mentioned before could be related to the same lean (or rich) conditions, and you would know instantly if you could monitor the trims live via scanner or Torque.

 

I think I might be on to the problem as I had it happen again today. Filling the tank does not seem to be the problem as I filled the tank before we left to go back to Lenox to get our ribbon. Drove about 60 miles stopped for lunch 30 minutes still OK. We parked the car waited about 1.5 hours, then restarted and drove by the review booth for the awards, still OK. After the awards were over we stayed another 2.5 hours before we started back. The car was sitting out in the sun all this time. When I got into the car to start home got the RP message as soon as the car started , but no check engine lite. I stopped and turned off the car then restarted it, still RP mode and now check engine lite came on. Drove about 20 miles and the RP mode cleared, but still had the check engine lite on. It will probably clear soon. I also noticed that my highway gas mileage has decreased. I was getting about 29 mpg@ 75 mph now it is about 23 mpg @75 mph. You may have a point about running to rich. My Jag service guy should be able to determine what is causing this problem??The last time I had this problem I had the codes read by Autozone. They read a knock sensor code and another code that their scanner could not read.

But it seems like a sensor is heating up, when the car is turned off after a drive and sitting in the sun for about 3 hours. I am hoping that the codes show up in the computer this time so this can be fixed. Thanks for your help.

Bill N
03 XKR