Check Engine warning

[daveji]

Hi all
I have enjoyed my "blue beauty" (2001 3.2 Executive) for 18months now and not a bit of trouble....untill this week !
There we were....belting (er cruising) down the M40 to London when at about High Wycombe an orange engine shaped warning light appears on the message center.......horrors !!
Diversion to the next service area and anxious consultation of the handbook !." Check engine" it says....that's all.
Car still going well.....no problems at all......worry about it when we get home. Looks like I will need the diagnostic computer "in anger"
Next day I try the first thing....disconnect the battery.....wait....reconnect (according to the recommended method) and start up. No change....light still on so I call Chris Forbes at CFS Motors.
"Bring it along straight away and we will have a look"...so I did...bet your life I did !!
The computer was connected and fired up and the scan revealed "Low catalyst efficiency Right Bank"
Mark at CFS then cleared the alarm and the ECU event log and on engine start......the warning light was gone. Job done...but what had happened ?
I was asked..."How much motorway driving do you do ?"
I answered truthfully....not very much, its been months since I was on a motorway. My journeys are mostly pottering about locally. I always warm up the engine every time I use the car and NEVER "short shift" The engine is never turned off before it is fully warmed up.
I was then politely and courteously told that my the problem I had encountered is very common.."happens all the time" said Mark.
It is aggravated by constant shortish journeys when the Catalytic Converters do not have the chance to get properly heated up.
When the "Cats" do eventually get really hot the sensors sometimes send a fault message to the ECU ...hence the warning light.
The point is that unless the warning light continually stays on or continually reappears...or the car fails the MOT emission test.. there is no need to worry, still less to start ripping out the Catalytic Converters or the Lambda sensors and replacing these very expensive components.
A good idea...if you use your XJ8 mostly for shortish journeys..is take it for "a blast" (legally of course !) down a suitable bit of road every couple of weeks to warm up the "cats" properly....and have fun ! Twenty miles should do ! These cars are designed to be driven far and fast...they are not "shopping trolleys" !!

[paulbarrie]

I had similar issue.
Please see my comment on New Arrivals heading under Hello Forum.
The warning light is still off after 5 months.

[Tony65]

Yes I have had the same problem. I had the warning light come on and took it back to the Jaguar dealer I bought the car from. He told me the same, catalytic converters giving a spurious signal. He removed the alarm but said he was not able to alter the alarm set point. He further informed me they get lots of XJ's coming in with the same problem.

The warning light has come on three times since then, I leave it and drive the car as normal and all occasions after a while the warning light goes off.

All this is ok if you are aware of this quirk, but what happens if the warning light comes on and it is another problem and not the catalytic converter playing up? Do I drive the engine to destruction waiting for the warning light to go off?

[daveji]

If the light comes on I would suspect the usual sensor glitch but play safe and do a diagnostic check. If the alarm resets ok all well and good,but its there for a purpose and there may be a real problem one day.

[Tony65]

If the light comes on I would suspect the usual sensor glitch but play safe and do a diagnostic check. If the alarm resets ok all well and good,but its there for a purpose and there may be a real problem one day.

How do I do a diagnostic check? On the first occasion while the car was still under warranty I returned it to the Jaguar main dealer who has the relevant equipment. It is going to be very expensive if I have to keep paying out to have a diagnostics done, cheaper than blowing an engine though I suppose.

Tony

[daveji]

Tony
Your local Jaguar Independant may have the diagnostic kit to deal with this problem and they charge a lot less than main dealers.
Try one of them and let us know how you get on.