Dials move to 120mph at idle

[GASMONKEYGARAGE]

I knew this when i bought her.

During normal foward driving the mph is spot on with the sat nav.

As soon as i stop, or not accelerating at low speed, the speedo and rev counter go clockwise around the dials,to the point as the title says i am doing 120 over or below when stationary.

Any ideas how i can rectify it.

Can take vid to show if needed

[davetherave1970]

My speedo used to dance at idle. Turned out to be a bad earth. One either side of the trans tunnel under the door handles.
Worth checking.

[GASMONKEYGARAGE]

davetherave1970 said:

My speedo used to dance at idle. Turned out to be a bad earth. One either side of the trans tunnel under the door handles.
Worth checking.

Thanks for that

[Blakeyspost]

Hiya, just looking back at the historical post and noticed we seem to suffer the same problem ref speedos. Have you managed to overcome the issue. I'm not so fussed about the speedo itself, it's the fact that the mileage counter also goes into overdrive !!

[SILICONEKID343HP]

Been trying to work out why the speedo reads within a few mph up to 60 then goes up to 120mph at 70mph. Can anyone tell me where the grounds are for the gauges.

[davetherave1970]

One either side of the trans tunnel under the door handles.
You have to remove the centre whale tail to see them.
Could just be the speedo read sensor either too close or too far away from the pick up.