Just thought that I would add to two pence again as my last (disgruntled) post was back in April.
Well I managed to get my car back and yes it has covered a marvelous 142 (weekend) miles since rebuild, been running it in nice and gentle watching was I was doing, taking care, checking the oil, fluids, temps etc etc and it has ceased.
Will I be trying to resolve this with the warranty paperwork that they gave me? I would find it hard as I wiped my backside with it and of this place when I finally got my car back.
Now with a reputable garage trying to sort out the problem.