Speedometer Problem (not a speeding query)

southernscouser

Today on my way to work and again on the way home I looked down at my speedometer only for it to be on 0mph! Fair enough you might think but at the time I was doing around 25mph and 50mph! :eek:

After a few seconds it shot back up to the speed I was doing!

I've only noticed it today but obviously it could have been happening for a while.

Does anyone know what could be causing this, is it something to worry about and is it gonna cost me alot to fix it? :doh:

Thanks very much guys!

SS

chrisw

I had the same thing happen on a Peugeot 406 and on those apparently it's a common problem with the speedo head itself. I sold mine before getting it fixed, but I should imagine they are expensive unless you go down the 2nd hand route.
Fortunately mine worked around mot time, but it is an mot failure and also illegal to have a non-working speedo.

Throbbe

Is it doing this fairly smoothly, or does the needle bounce around a lot. If the latter I'd suspect the speedo cable before the clocks.

New cable cost me £15-ish when mine went, and about 2 hours of my time and skinned knuckles to replace it although I replaced a couple of dash illumination bulbs too. I'd expect a competent mechanic to turn it around in less than half that time!

southernscouser

Throbbe wrote:

Is it doing this fairly smoothly, or does the needle bounce around a lot. If the latter I'd suspect the speedo cable before the clocks.

New cable cost me £15-ish when mine went, and about 2 hours of my time and skinned knuckles to replace it although I replaced a couple of dash illumination bulbs too. I'd expect a competent mechanic to turn it around in less than half that time!

Well I've only seen it happen twice but what happened was when I looked it was stuck on 0mph with no movement and then it would suddenly shoot up to whatever speed I was doing and would stay there as if working normally!

balsingh

Most speedos these days are electronic and they dont have a cable - they work using a pulse which is sent from sensors near the wheels or gearbox. As a result, the fault could be at the speedo head ... then again it coudl be the sensor that sends the pulse to the speedo head.

tomstickland

Most often it's water/corrosion on the connectors, WD40 can sort it.

southernscouser

balsingh wrote:

Most speedos these days are electronic and they dont have a cable - they work using a pulse which is sent from sensors near the wheels or gearbox. As a result, the fault could be at the speedo head ... then again it coudl be the sensor that sends the pulse to the speedo head.

Thats what I thought! :eek: :rolleyes:

Throbbe

^^^ Yep. I keep forgetting my car is nearly 20 years out of date.