Speedometer Trouble

[Schneller 3er]

I have this problem with my speedometer....I was drving @ about 40 MPH, and all of a sudden it drops to zero, while I was maintaining the same speed. A minute later it went up to 40 MPH again.
It does that quite often, regardless what speed I'm at. What can be wrong? Loose connection? Please give me some ideas.

TIA,

Dan

[mikeedler]

replace the sending unit in the dif. it fixed mine that was doing that.

[Schneller 3er]

is that hard to replace, and where would I be able to purchse one?

Thanks,

[mikeedler]

to easy, 2 10mm bolts on the rear diff cover, and one clip. i got one from a parts car that i had laying around. it will be a dealer part only of you have to get a new one.

[eeki]

First things first, check the connector on the diff for dirt/corrosion and clean it.

The problem can also be your instrument cluster. Due to vibrations, some of the components on the board can be a little loose. If that's the case, you'll have to re-solder them.

[Schneller 3er]

I will jack the car up on Wed, and take a look at it. I'll clean it up and see if the problem's still there.

Thanks again

[PanamaE30]

Well, before you go through all that trouble I'd troubleshoot the instrument cluster first. If it happens again, smack the dashboard on top of the cluster firmly and if it jumps back alive you've most likely got some loose connections.

[Schneller 3er]

Well, before you go through all that trouble I'd troubleshoot the instrument cluster first. If it happens again, smack the dashboard on top of the cluster firmly and if it jumps back alive you've most likely got some loose connections.

I'm installing my suspension on Wed....so I will look at and clean up the connectors. If that doesn't work....I'll bang on the dash..... ;)

[PanamaE30]

lol ok, in that case go for it.

just thought I'd give you a quick try at avoiding a ton of work. I had a similar issue, and sometimes percussive maintenance is highly effective.

[mikeedler]

replacing that sensor is easier than taking out the dash. I would doubt its the dash, the grouning nuts that usually come loose are for the tank, and temp guages

[mikeedler]

replacing that sensor is easier than taking out the dash. I would doubt its the dash, the grouning nuts that usually come loose are for the tank, and temp guages

[PanamaE30]

Hmm.. could it be SI batts?

[Schneller 3er]

Hmm.. could it be SI batts?

I hope not...In any case I will let you guys know.

[damionphillips]

Any Progress? I've got pretty much the same problem, but my gas gauge does the same, and my odometer stopped a couple of years ago... Ideas?

[Schneller 3er]

My speedo started working once it got warm. When it gets cold at night, it stops working again. The gas indicator, did not change. it still acts funny. The light comes on, and it still shows half tank. I'm puzzled, no clues.