325 tds speed not matching tachometer
I hope you're all doing well! I have just purchased a 1997 325 tds. However, when i drive the car, it feels like the RPMs do not match the speed! For example, at 110km/h, the tachometer shows 3500rpms! At 100 at 100km/h it shows 3000rpms, this is all in 5th gear in a straight line.
I have checked the diff, it's the stock diff (2.56) gearbox is the same, stock. Clutch is not slipping. What could possibly be wrong! Could a bad turbo cause this? A bad MAF? A vacuum leak? I am confused and would appreciate any help you might provide! Thanks.