GT 2.0 JTS Lumpy Idle & Motor Control System & VDC Sensor Failure
Just had the cam belt changed on my GT 2.0 JTS (6 Years old 30 K Miles). Now Iím not sure if it is my imagination but the idle does not seem as smooth as it did last week before having it done. The cars performance is bang on throttle response is instant and it revs fast and cleanly to the red line. Its not so much a rough idle as wobbly idle that seems to pulsate at times through the steering wheel. The problem gets worse with the air con on. But sometimes its absolutely fine nothing at all. Sometimes switching the air con off makes it disappear completely sometimes it just reduces it. It does not seem like a consistent vibration that may be cause by the balancer being out for example which you would imagine would cause a vibration all of the time.
Iím not sure if it is connected but for the last 2 years I have been suffering with intermittent VDC sensor failure leading to Motor Control System failure messages and restricted performance. The car has been on many diagnostic sessions but no one has found any cause for these messages. This usually occurs if I have accelerated hard (ish) then slowed down suddenly - but it happens very infrequently so hard to determine exactly what causes it. After a restart I get full power back but the car feels Ďhesitantí and the MCSF message / light remains on. May be a day later this will clear and every thing is great again for a month or so.
Two main dealers have looked at it since the work was done and both say the car is running fine, one of the better ones they have seen.
Also Iím not sure if the fuel consumption has got worse Ė its hard to say as generally I donít use the car much or for long journeys.
Iím at a loss what to do as everyone who looks at it says there is nothing wrong Ė but I think there is and I am certain it idled find before the cam belt was done, but Iím sure if that had been done wrong the car would not rev so freely and pull so well all the way to red line. Performance wise it feels exactly as it did before.
Some people have said it could be the MAF others wheel speed sensors. Any ideas?