Here's your post from the other thread.

My engine light came on as well as the message "restricted performance" today. Since it's not overheating and seems to run fine otherwise, though it seems to have lost a little "pep". I dont want to just cycle the key and forget about it if there is a problem. Iwould like to get it addressed while it's stillunder warranty. What would legitimately cause this message? I got the message after "gettin' on it" a little on the Interstateon-ramp. The dealer is only 124 miles from me so it's not particularly convenient to bring it in to be told it was a fluke. So how does one distinguish between a legitimate problem and a "fluke" before committing to a three-hour round trip to the dealer?

 

Lez295- You need an OBD II scanner to check for codes. Otherwise you have to go to a dealer or independent shop. Can't help you with out the codes.

Stepheng - There is a reason why warning lights come on...

FL XJR - You should invest in a inexpensive OBD II scanner since you are far from a dealer, that way at least you know what you might be dealing with. There was an issue with your Model car and the "restricted performance". It was a programming issue but that was back in 2002. Do you have a complete dealer history to see if it was done? By the way, your extended warranty wont cover programming. What dealer do you go to?

 

I went to Crownwhen I hadmy Vanden Plas, but I lived in St.Pete full-timeat the time. Now I go back andforthbetween houses there and Gainesville.I took my XJR to Crown once, butI am thinking about switching to Jaguar of Tampa. Any clue on the cost (and where to get) an OBD II scanner? I have a complete history of the car along with window sticker and warranty policy in a ring binder. I had Crown print the warranty and recall history butif I recall, there was only one item - EGR (or something like that I think).I will look through the recordsto see about anything else...

 

I checked my vehicle history and no record of reprogramming.A few code campaigns showed up: PartLoad Breather Hose Mod, Drive Belt Replacement, High PistonBlow By, and EGR Transfer Pipe. Onesummary historyhas a few services I cannot identify. The only have an operation code next to them. They were from 6/2001, 12/2001, and 1/2002.

 

You can pick one up at any auto parts store. You'll find a better deal online, just search for OBD II scanner. $100 should get you a decent one. All you really need it is to read the codes.

TSB 303-49, 86.99.13, BX DF 42 <<<< do you see any of that on the history you have?

 

No codes like those. They may just be for oil change and lube service. I'm curious about the OBD scanner. If I dont have a way to read what the error codes mean, what would be the point of buying the unit? Can the error codes be deciphered somehow?

 

i had the performance restriction happen on the S-Type R, the CEL was on, and the reason it was on was due to 2 cyclinders misfiring. Changed the plugs, and two of the coils and all was fine. Not sure what ure case is, but hope this helps.

 

I just came from a local shop I found in Gainesvillethat has the Jaguar diagnostic computer. As luck would have it, the Jag tech is currently in Europe. But the shop owner ran it throught the computer and says that it looks like it may be the airflow meterin the intake neck just after the air filter housing. He says at idle (661 RPM) the Long-term fuel trim bank 1 is -0.79% (running rich). Short-term fuel trim bank 1 is 1.58%. At 2660 RPM, Long-term trim bank 1 is 6.3% and short-term fuel trim bank 1 is 11.8%. (running too lean). This causes him to think that the car is not getting sufficient airflow. Kinda makes sense to me, because when I was accellerating on the highway it felt very bogged down like it couldnt breathe. Now the engine light is off and it runs like a scalded dog again with lots of pull off the line. Question is, I seem to recall reading a threadwhere something air intake-related would get stuck and need to be cleaned (throttle body, perhaps?) It would cause cars to not start because they wouldnt get any air and flood out. I wonder if there is something I can inspect and possiblyclean here at my house that would fix the issue before making the 120+ mile shlep to the Jag dealer in Tampa. I will have to do a search - I think Envy replied in that thread with the procedure for cleaning this component.

 

Found it...

Guess I'll give it a try and see what happens. I'm not going to disconnect the battery, though, since I think the purpose of that would be to reset the error message and mine's not showing the error message anymore.

 

The readings at idle look normal. . Anything over 10% (rich or lean) at idle is when you have an issue.

A lean condition means you have more air (unmetered) than fuel. The mechanic had it backwards.

A common cause of a lean condition is a vaccum leak. Air getting into the engine with out being metered by the mass air flow meter.

Check the intake tube (the plastic pipe from the air box to the throttle body), make sure it has not holes. The intake tube tends to crack where it flexes. Check to see if its tight on the throttle body.

To clean the throttle body, just the remove intake tube. If you see a black build up in the throttle plate, clean it with carb cleaner.

 

Disconnect the battery, the purpose is to let the throttle plate readjust itself to proper idle.

On Jaguars, disconnecting the battery wont clear the codes.

 

Thanks for the follow-up. Not sure where the fault occurred. The intake pipe was secure and no cracks or holes. I cleaned the rubber gasket that fits between the throttle body neck and the intake pipe. It was a bit dirty/gritty. At anyrate, it seems to operate just fine now...

 

My bliss was short-lived. The "restricted performance" message came onseveral timeson my way from Gainesville to St. Pete. Everytime I accellerated on the on-ramps the warning would come on. It would go out after about five or ten miles at highway speed but, of course, the engine light stayed on all the time. Made a pit-stop at Aston Martin/Jaguar of Tampa. Fortunately, my timing was impeccable and they got the car right in and diagnosed a bum airflow meter. (deja vu, n'est ce pas?) They also said the fuel system was about 5psi shy (which would contributeto it's losing pep on spirited accelleration). So, replaced the airflow meter, replaced the fuel filter, performed fuel system clean including throttle body service, rotated the air in the tires and topped off the blinker fluid (muffler bearings had already been repacked ).Picked it upon the way back from St. Pete (they gave me a loaner X-Type to fart around in whilst my car was being serviced) and it has the old pep again! No issues on the way back to Gainesville. (hence, I'm happy again )

 

Just taking my "New" 04 XKR with 30K miles home. Exact same thing, driving along 70 mph, all of a sudden temp guage goes to hi with red warning light, orange warning and "restricted performance" msg & "check engine" show up. Checked under hood, no overheating, drove 10 miles @ 65mph to next town. Shut down to check, on restart "check engine" light on, all else back to normal. Will call dealer in AM. What would "Air flow meter" have to do with Temp guage/light malfunction?
.....bob

 

Good to hear you got it sorted.
What are "muffler bearings"?

 

restricted performance, hi temp light was caused by "stuck" thermostat. Jag replaced stat, temp comes up to normal now, seems OK....bob

 

when I asked that the first time someone mentioned them I was told that they are in the same TSB as the constant velocity pressure shackle and the oscillating roggle sprocket.

 

FL XJR:
I would be a little leary of that "shop owner"- Heres why. The symptoms you describe are NOT for a restriction in the intake. When you are at idle, the engine has a relatively EASY time pulling in air. Your car is OK there. Your car is lean at speed, when the engine would have a harder time pulling air air. So, what you have indicates a lean problem. That would indicate one of two prime culprits. The first is an air leak, and a good bet is to check the part load and full load breather tubes for a split. There are pictures on here somewhere, but he full load breather is approx 1 inch diameter and is right behind the MAF you described. Or look for a crack on the resonator on the air intake plenum.
The other possibility is low fuel pressure. Check it with a guage you buy or borrow from autozone. It should be about 40 psi higher than the current manifole vacuum.
Good luck