lol

Ok as blunt as it sounds, the problem is that you have a Mk4 and the instruments used in them are just cheap and tacky rubbish. Of the ones i've seen that work they dont operate smoothly and dont read accurately. I had one car that the rev counter wouldnt work for the first 30 minutes and then miraculously sprang into life and would only stop working again when the car was left for several hours, and another one i had the rev counter used to lie and read falsely for the first 5-10 mins of being on!!!