Technical Strange Speedo/Rev Counter readings

[2000JTD]

Hi, the speedo and rev counter on my JTD are acting up in that they both show much higher readings than the actual. When the ignition is turned off the speedo often stays at around 20mph whilst the rev counter does turn off. When the car is first started the speedo dial flickers.
Garage not sure what the problem is. Anyone else had this problem?
Cheers,
2000JTD

 

[faster4_tec]

not exactly the same as that, but sometimes the speedo reads 22mph when the car is fricking stationary, had it gone right round the dial and hit the underside of the bottom stop, i was prob actually doing 90mph and it was showing equivilent of 140mph

 

[smelluel55sx]

My speedo shows strange readings. just got it fixed but now it says im doing 70mph when im doing 90mph. i have no idea why.

 

[rpaterson]

I think that the Punto uses a sensor on top of the gearbox for working out revs / speed. Maybe find it and give it a clean?

 

[joecinq]

not exactly the same as that, but sometimes the speedo reads 22mph when the car is fricking stationary, had it gone right round the dial and hit the underside of the bottom stop, i was prob actually doing 90mph and it was showing equivilent of 140mph

That old chestnut

 

[CKYDave]

I've had a similar problem, my speedo got up to about 44mph then it stuck, and as the car got faster it would eventually drop down to 0mph and start going up again. When the car stopped it would jump back up and would often say I was going at 20mph when the car was stationary. I took the car in to be looked at and Parks were f'n useless, basically told me I was talking crap. I just gave the top of the dash a good smack out of frustration one day and it has been fine ever since..

 

[pritch]

Fitting bigger/smaller wheels causes the speedo to be off of course, but not this much. I'd go with just giving it a good slap. Always works with my sidelights