Lazy Speedo Problem

[tvrjohn]

Speedo from cold takes miles before it starts to work
and is gradually getting worse.
What can it be ?

[gbbird]

Mine did this a while ago - used to take a good 20 miles before it started to work. As long as everything else is OK (eg rev counter) it is most likley the Speedo module - around £40 for a new one.

[mike_e]

Is the odometer misbehaving as well or is it just the speedo? If both misbehave it could be the hall effect sensor on the diff rather than the speedo itself.

[jellie]

mine used to play up and not work for a few miles until the engine was warm. I had the engine rebuilt and the porblem vanished-possibly a dry earth or something. Anyway its an expensive way to fix a speedo!

[tvrjohn]

Thanks Mike E, Both milometer and the speedo malfunction at the same time.
Can imagine the diff sensor is a **gger to access !

[mike_e]

Actually it's not too bad, crawl underneath or remove the wheel to access. Sensor is mounted on a bracket behind the inner CV joint (on the nearside IIRC), look for the toothed wheel inboard of the CV joint. Sensor gap may be too excessive or wiring contacts corroded.

Still could be the speedo but the sensor is a little easier to access and, as it's exposed to road dirt etc, a good place to start looking for the problem.

My sensor went intermittant before failing altogether.

[tvrjohn]

Thanks for your help Mike E