Can anyone help. I have an onging problem with my XJ8 4.0 (yr 2000 uk model) that Jaguar cannot and are not interested in solving.
This is the story.
Earlier in the year the car developed two symptons - Firstly, when starting the engine it would rev up to 2500/3000 rpm and it wouldn't always return to the proper level and one would have to put the car into Drive (with the foot firmly on the brakes!) before it would settle. Scary stuff in the car park!
Secondly, following the occasions when the car didn't start properly, it would start to develop a shudder and stutter. At lows speeds the car literal jerks and surges before the engine revs fall back. At higher speeds the Car doesn't want to slow down. If you take your foot off the accelerator the car just drives on as if the Cruise Control is on (which it isnt). The symptons become increasingly frequent, violent and ultimately dangerous. At speed 60mph+ this causes a lot of shudder and the traction control and stability control to fail. All the lights come come and warning test come up on the dash. The car would then go into fail-safe mode (5mph! in a hurry) and on one occasion it stalled in the fast lane of the M23! Afterwards you just wait a minute, re-start and all is well again for 10 mins or another few days.
Jaguar initially couldn't find anything wrong - no negative readings on the computer. After encouraging the dealer they contacted the engineers at Jaguar and suddenly they fit, at no cost outside the warranty period, a new throttle housing. (Evidently this is silent recall). They say the throttle had been sticking.
All was well for a week when the symptons returned - they are much less pronounced but I am concerned that they will worsen.
I have tried to isolate when it happens and there seems to be two circumstances that set it off a) Taking the car out of the Garage and putting it back later without going anywhere. b) The wet and damp. There seems to be some correleation with the weather but this is not 100% scientfically consistent. (It seems to be the change in the weather not the actual weather! i.e dry to wet not simply wet).
My dealer who, when all is well, is excellent simply doesn't want to know now there is a problem.
Has anyone had, or know of, a similar exprience/fault and can anyone suggest a cure please!
Thanks. Ian.