When I start my car, about 75% of the time the needle for the tack sticks at 0. I just need to tap the dash a few times and everything's good, but it's a little annoying. What would cause this?

 

No help here, but I've got the same problem. I have ignored it until now and just tap the gauge like an obedient owner. Don't want to anger the german electrical fairies you know...

Seriously though, I'd love to here any solutions to the problem.

 

For the cable driven '83 it is either the cable or the tach is on the end of its lifetime.
For the electric '86 it can be sensor contacts at the gear box. (Left side, above the drive shaft CV, close to the exhaust.....)
Cleaning these (and then clean some grounds under the dash) could solve it.
TakeCare

 

'83's tachs are also electrical. The speedo is mechanically driven.

 

i have the same problem with my tack also.i have a early 85 944 and it sticks alot of the time and it's aggivating. i would like a fix also!!!

 

I have that problem with my speedo, sometimes when I accelerate from a stop, the needle sits on zero. After a few seconds, it'll jump up and work fine.

 

Sharky- sounds like it's about new speedo cable time, does the speedo needle sometimes jump? yopu may be able to spray a little wd-40 into the speedo cable. The jusnk builds up inside there. Mine has worked fine ever since I did this.

.. I have no idea about the tach- I havent run into that problem... yet..

 

FWIW, I've been tapping the dash to get the tach running in my '83 for several years.

Still counts rpms fine, though.

 

Sorry Chris, I have an '87, everything is electric.

 

I have the same problem. I have not investigated any fix other than a gentle "tap tap", which works every time.

 

I have the speedo problem, a little tap and works fine but after each time I stop, it's annoying

 

Wow, forgot about this one! So no known fixes? Oh well, I guess we'll all deal with the annoying-ness of it...

I've resorted to just letting it start working whenever it feels like it, the engine sound is enough for me!

 

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by iloveporsches:
<strong>Wow, forgot about this one! So no known fixes? Oh well, I guess we'll all deal with the annoying-ness of it...</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Maybe we should get Danno to develop an ignition-activated solenoid-based dash tapper?

 

yep... happens to me every once in a while, will not do it for months, then do it every time I start the car for 3 days, then skip months again... whatever

 

The needles on my 86 N/A bounced all the time, I removed the instrument cluster and cleaned/re-soldered it. Also cleaned the grounds under the dash and battery ground to engine/ body. All the needles are stable now.

Procedure for this can be found at: <a href="http://www.clarks-garage.com" target="_blank">www.clarks-garage.com</a>

HANS, the sensor in the gearbox is for the speedo. If the tach sensor would be in the gearbox, engaging the clutch would result into 0 RPM on the tacho while the engine is actually idling and running at 900 RPM.