Had the same on my old Diesel... easy fix really
Had nothing but bad experience with the AA and RAC (AA left me in the middle of M4 slip road during rush hour to call out a recovery truck.. took 2 hours for truck to arrive, then he deemed it too dangerous to recover me from said location and had to close the slip road (with police help) before putting me on the back of the truck.... Apparently the original AA guy should have towed me up the sliproad and onto the hard shoulder... AND he should have raised it as priority 1 due to location, as it was it was put through as low priority...
The only Breakdown service thats any good in my experience is green flag...
Mind you round here you allways get the same company recovering you (Boarhunt Garages) so its just the initial diagnosis that counts