MY car, a 2006 model VW Golf 1,6 Comfortline, is on 60000km and is behaving strangely.
Every time I waiting traffic lights it vibrates heavily as if it is about to cut out. Sometimes, when driving along, it will suddenly start misfiring and lose power, and then quickly correct itself.
Furthermore, when the handbrake is on and the gearbox in neutral, the engine will occasionally start revving very high (up to 6000rpm), then return to normal idling speed, then rev again, repeating the cycle perhaps 7 times before stopping.
Sometimes it doesn't stop and I have to switch off the engine, afterwhich it will be fine. The car has a complete service record and no accident history.
Charlotte, this is even more mysterious than the problem described in the previous question.
I again called upon the experience of my trusted technician friend, and he recalls that he has had several cases of VW products (specifically Polos) exhibiting exactly these symptoms.
The fault was traced to the 4-pin water temperature sensor fitted on the side of the engine facing the grille.
It's a dual-purpose sensor, feeding information to the car's electronic control module and also switching the radiator fan on and off as necessary.
If it malfunctions you get the kind of erratic behaviour you mention.
I suggest you have that replaced and see what happens. If it doesn't solve the problem we will have to delve deeper.
Please let us now the outcome. It must be a nightmare to drive the car like that.