I realise this topic has been aired before. My situation sounds a little different. My car, a 59 plate, has driven >160k miles relatively trouble free. At about 95k and just before the 5 year warranty ended I had a complete engine rebuild due to the wrong coolant being used at manufacture. The car has continued to run fine until last year.
I now get a violent juddering at about 1500 rpm ( just cruising at 30-40mph ) as if I am i the wrong gear and the engine is stalling. Going manual shows I am in 3 and if I change to 2 the revs go to > 2000 and the problem goes. If I go back to 3 it will re-occur. If I am going slightly uphill or if the car is cold there is no problem.
I know this is a dumb question but how many gears are there in the auto gearbox? Could I have "lost" one? or is it a control issue of not recognising the load on the engine and adjusting the gearing to match it?
