Hi, I had a few runs today at the RAC skidpan and at the end I noticed my tacho was frozen at 3000rpm, then it would jump instantly to 4000 or 2000 in a flash. The engine felt normal to drive and the boost gauge was normal. Not sure if its an electrical thing or some sought of leak. I'm going to get it serviced this week anyway but I was wondering if it could be serious or minor so I know how I should drive for the next few days.

Cheers