I started my car up in the weekend and there was a loud tapping noise. my heart sunk. i turned it off straight away and racked my brain as to what it could be and what could have changed since i last drove it. I got my mate and he started it while i listened and it happened again. we spent 1 1/2 hours thinking and testing. we gave up untill the next day and i was ready to give in and start saving up and then my mate said it might have something to do with the oil pressure or something so we started it again and he was fiddling THEN........
he pulled out the dip stick and the noise stopped!! I was about to take the engine out and strip it and try to find the problem when after all that the dip stick was bent and rubbing on the crank!! so the motto is check out the small things and CHECK THE DIP STICK on the a12!!
sorry for the long story but i hope it helps some one.