The speedo on my 00 mk4 1.4 ecotec has gone loopy. It sometimes reads correct. I was at the shop a few minutes ago and I was stopped at the lights and it read 140mph then when I was doing about 30mph it was reading about 160mph (not that the clock goes that high). Its completely random as to when it does it and as to how far off it goes.
Anyone come across this before and know what causes it and how to fix it??