speedo working intermittently

marineblue911 · 08-10-2004, 10:15 AM

hi folks,

i have been having a misbehaving speedo that works intermittently. Is it a speedo problem or is it the sender? Its either both the speedo and mileage works or both are dead.

I also am feeling that when I pull hard in first gear, when i upshift, the gearshift almost pops out of gear when i engage the clutch. Don't have this problem with second gear. Is this a sign the transmission mounts are shot?

Thks,

Paul
Marine blue 87 911 Carrera 3.2

jdowty3 · jdowty3's Garage

I had a similar issue. I replaced the sender at the tranny but that didn't fix it. I traced it down to getiing only about 2V on the 12V wire at the speedo which was caused by a bad/loose connection at the fuse block screw.

ZOA NOM · ZOA NOM's Garage

You didn't press the trip reset while you were moving did you?

}{arlequin · }{arlequin's Garage

Assuming the electricity is there, starting from cheapest to most expensive way to diagnose the problem, you should get a new speedo cable (approx $35) and see if that takes care of it.

Then you can take the speedo apart and check it out internally. While you're in there, fix those odometer gears too.

The next step would be to buy a replacement speedo (about $100 used.)

After that, your other choice would be to send the speedo out for a rebuild. Not sure of the cost, but others have done it w/ great results.

jdowty3 · jdowty3's Garage

The 88 has an electronic speedo so no cable to replace and odometer gear only affects the trip meter and not the MPH reading.

Paulporsche · 08-10-2004, 02:56 PM

Check the electrical connections.

}{arlequin · }{arlequin's Garage

oops. my bad. nevermind.

ecm911 · 08-10-2004, 08:37 PM

I agree with Paul - I had a similar prob w/ an 83 . It was a loose connection at the speedo.

They are very easy to take out- just a rubber gasket holding it in. Do a search I am quite sure you will find detail instructions. Just use a cloth or something to protect your dash.

Earl