We have an '02 plate SEAT Alhambra 1.9TDI. In the last month or so, my wife has lost power twice when driving it. She switched the engine off, and everything was fine again. In the first few days, we were concerned that 'something' was noisy at low speed - initially I thought loose plastic engine cowling vibrating - as small blip on the accelerator seems to make everything run smoothly. It also seemed very 'crunchy' when manoeuvring at slow speed.

We were driving to the the local garage when I could also hear a metallic rattle from the engine bay (sounded similar to rattle you get when one of the suspension springs breaks and sits in the cups). The garage checked everything for loose bolts but could find nothing. They decided to test drive it and the car lost all transmission. They have diagnosed a gearbox issue and suggested it may be a common fault on the 6-speed boxes - a weak rivet? Is this right and, if so, is it likely to be fixable without recourse to a new gearbox, or a gearbox specialist?