Author Topic: Speedometer... indulge ourself in my story (Read 3589 times)

snesar · « **on:** August 20, 2007, 12:30:53 PM »

Helo everyone -
First of all let me say that I did thorough search on this topic and there is a lot of good information and lead.. I followed them before bugging everyone on a beaten topic... the speedometer.

I bought this vehicle not long ago, and its really nice...except that the speedometer intermittently quit to work (along with mpg ind. and tachometer become static, i.e. teh miles dont increase). When it worked, everything worked fine.

First I checked the speed sensor at rear diff. turned out no problems there, the rubber housing is fine and tight, cant pull it easily, pulled the wire to check, great connection, no problems there (which I can see).

Second I started taking the board out. After struggling with it, finally managed to get it out without screwing anything esle (phew...). The solder jointes on the board didnt look bad, no problem with the battery on SI board (no issue with SI). I re-flow them anyways with care, put it back togather. looked at the connector pins on board, seemed fine and straight. Put the pannel back togather, pushed the connectors all the way back in, made sure they are all the way down and tight.

First half hour, speedo worked fine, no issues and I was happy that the time was worth-it. Then on a turn, bham... it went down (along with mpg and miles). A tap on the face brings it back to life quickly. I suspect that its happening very rarley now, but will be frequency with time & temperature.

SO her are my questions to you Messers:

1. Anything I missed?

2. Is there a way to get the top part of streeing column cover off easily? I had to use force and pullung to get it out (and take the ignition connector on teh left out). If thats the only way, I'll be affraid to do it again, I'll break something for sure this time. Looks like it was put on before steering colomn? Any better way to get this easily?

3. I was thinking what if my connector on cable side is bad? Where the wires from cable connect the housing and pin recepticle? IF thats the case, how will I ever fix it? Even a new speedo is going to have the same issue?

4. If I get a new/used board, do I have to live with whatever the miles are in there, rather than what my vehicle has?

5. Has anyone found any other place where it could be wrong? As a tap on face brings it back, I concluded that its not the sensor.

Please help if you can, even your comments will be helpful.

Thanks

PS: Its a 1991 318iS with 125K miles. The cluster is VDO.

D. Clay · « **Reply #1 on:** August 20, 2007, 12:41:17 PM »

There are grounds on the back of the cluster. My temp gauge doesn't work at first sometimes until I tap it with my finger. Mileage is easy to change but takes care. There is a wire over the top of the row of number wheels. Use something like a pointed knitting needle to lift it up and the wheels will roll freely.

snesar · « **Reply #2 on:** August 20, 2007, 04:01:41 PM »

Hi D. Clay,

Thanks for the input, it makes sense.
Can you please explain a little more where these ground connections are which you mentioned? Any pictures? I didnt notice any sping loaded connection either on teh pack of the unit (outer blue color), or when I was re-soldering. Are these inside the indicator units? (which I didnt open).

Any further explaination will be helpful. Also, do you have any trick to get the upper streeing colomn cover out?

Thanks

bmwman91 · « **Reply #3 on:** August 20, 2007, 04:31:31 PM »

Hey welcome aboard!

I too am actually interested in any top-cover removal tricks. I had a lot of trouble getting it off.

johna · « **Reply #4 on:** August 20, 2007, 05:43:33 PM »

I could get my cluster out very easy, no need to remove steering wheel. Once you have all of the screws out, you just tilt the instrument cluster down so you can unplug it, and then slide it out past the centre console. Quite easy really. This is with right-hand-drive cars however, maybe LHD is different?

91318isguy · « **Reply #5 on:** September 07, 2007, 07:16:26 AM »

Hi Snesar,

Sorry to hear the Speedo is giving you issues. But on my first M42 I had the exact same issue. The thing was that it was the speed sensor itself. The connections on the back of the speed sensor was just as you say, perfectly fine. But the sensor itself can go bad. I got a new speed sensor, and even though the new revision of the part was a little different regarding the bracked used to hold it tight in the diff, a little adjustment in the bracket and everything was fine.

$60 for a speed sensor from the dealer (my tach was fine, but the odometer, speed and MPG gauges didn't work).