Transmission problem

[Keith Morgans]

Hi everyone, I've just joined but am currently on my ninth jaguar and its this ninth one that is giving me a problem! Its a 2009 model XF with the 2.7 litre engine, green with cream upholstery and, apart from this fault, is a brilliant car. it has now done just over 100,000 and in the last four months has had a gearbox Oil change, flush and new filter, both belts and pump changed, new intercooler and i think that's about all. The fault started some months ago and before I had any of the above work done, normally the car runs very well but occasionally it drops out of gear, this usually happens when accelerating whilst going up a hill but can also happen on the flat while slowly accelerating. It can happen in Drive, Sport or when using the paddles in sport mode, it has happened when accelerating to overtake lorries on a motorway, not to be recommended and very embarrassing particularly as there was a BMW on my tail! Most of the time the gearbox behaves well and all is usually normal for the first half hour, at least, of a journey. I have done a two hour journey where it hasn't occurred, I've also done a two hour journey where it has happened four or five times. Nobody seems able to help, certainly not any main Jaguar dealers, it seems to be a little better since I replaced the intercooler. I was told that the car had been chipped to take it up to 270 hp and it does seem to accelerate very well indeed, I took it to specialist re-mappers and told them I wanted to take it back to normal this they started to do but then found out it hadn't been remapped at all, when I mentioned that the car had been chipped and not remapped, they said it was the same thing. I would agree that the end result is the same but i think chipping and re-mapping are two very different procedures.  I wanted whatever had been done to be removed in case it was the chipping that had caused the problem.

Finally, when it drops out of gear the gearbox fault light comes on, I pull to the side of the road, stop the engine and then immediately start up again and everything is fine for the next half hour or so.

Any helpful ideas would be really appreciated.

Thanks, Keith.