1996 300 Tdi- with 89,000 miles FSH- I noticed on a drive out yesterday that the rev counter needle is dancing between 1,000 rpm and 3,000 rmp with the vehicle doing a constant 60 mph

When Idling it jumps between 700 rmp to just over the 1,200 rmp mark - the engine I might is reving and idling as it should - its just the needle that seems to have lost the plot

any idea's guys??

Les

Loose connection on the back of your alternator, clean the contacts and check the connector isn't loose.

Thanks - I'll give that a go

Les

Also check your belt, it could be slipping.

Notice the same until i changed the alternator, I would look at the connections as red hand said. cheers.

Combination of both - loose belt and dirty connector on the alternator- new belt and some wd40- problem sorted

Thanks guys


Les