Speedo Problem

[g8nightman]

Hi Everyone

I was in my 94 S4 the other day and noticed that my speedo was acting up what happenes is that when the car starts rolling i get the needle start to jump around all over the place has anyone ever had this problem if so what did you do to fix it any help will be appreciated.

Thanks

[Dr.Hess]

Likely the speedo cable is sticking at one place. You can try greasing/lubeing the cable or wait for it to break, at which point the needle will stop jumping.

Dr.Hess

[deecee]

The needle jumping is typically a sign that your cable has already broken....

[erik_t]

The same thing happened to me three weeks ago. On one of the hottest days this summer the needle of the speedometer suddenly started jumping around (in my case. the temperature caused the problem as you will see). I removed the instrument panel and after having opened up the speedometer it appeared that the ring with the magnet that is connected to the rotating shaft had slipped about 1.5 mm, providing a bit of play and making contact with the axis on which the needle is connected. This caused the jumping. After having locked the ring in the right place, the speedometer worked ok again. I now put a protective piece over the binnacle when my car is parked somewhere for a couple of hours in the sun.
Oh yes, if it is the cable you will be able to see that before you need to take out the speedometer.

[erik_t]

One more addition to me previous answer. When I noticed the problem with my S4, I suspected the speedo cable too, but it was still ok. So, since the speedo was broken anyway, I decided to risk it and open it up. Fortunately I succeeded in repairing it. My advice (perhaps trivial), do not open up the speedo unless you are sure its broken and you think you can repair it. As an alternative to either repairing it yourself or having it repaired, VDO has an electronic replacement part and in my S4 (revised wiring harness) the required cable from the ECM is available under the binnacle. I will put a drawing of the issue with my speedo on my website at:
http://homepages.ipact.nl/~theunissen/
Good luck
Erik

[jrjajs]

If your speedo does not work at all, ie: jumps all over sits at a certain speed then jumps you may want to send it off to a repair shop if you are not comfortable with doing a speedo repair yourself.

I had the same problem, pulled the binnacle cover and disconnected the cable to check if the problem was in the cable or not (you can observe the cables spin up and down, or have a friend ride along and watch it) it should spin up and down with changes in speed very smoothly. If it doesn't you most likely have a cabe problem.

My problem was definitely in the speedo itself. With a little bit of spray lithium grease behind the edges of the rubber boot around the speedo (from the front of the binnacle), some patience and elbow grease out it came.

I openned mine and deternmined that I did not have the knowledge to fix it. If you are in the USA I can reccomend an excellent repair shop.

The compant is:
APT Instruments Intl, Inc
9632 humboldt Ave. South
Bloomington, MN 55431
952-881-7095

The speedo was completely rebuilt, looked better than when I sent it and has performed very nicely since being reinstalled (which includes a lot of very hot and humid days of late)

Hope this is of some help to you.

[adrianmugridge]

The speedo in my 89 Turbo went somewhat wrong a few years ago. It started jumping about a bit and then it was jumping from 0 to 160 in a couple of seconds !!

It went back to the manufacturer and they fixed it in about a month (VDO, IIRC). I had to drive around with a big hole in dash but you just have to try and use the revs instead.

Adrian
Sport 350