zenithblue993

Hello, this is my first post on here. But i have a 1997 993 porsche 911.

The speedometer when i turn on the car and drive, the needle will usually stay at 180mph always. Sometimes it will move between random mph. Also the odometer is stuck too at 15,655 miles. I've been reading on here that maybe the gear is broken for the odometer but i don't know if that will fix the speedometer.

Also, on the digital computer, the mph is wrong, and so is the miles till empty. Not sure whats going on here. Any ideas?

SchnellAuto

gear housing in the speedo broken...talk to kevin at North Hollywood speedometer....

he will get you squared away..tell em lemon sent ya


Lemon

Kein_Ersatz

Must have been driven Flat Out by a previous drover . . .

Mister C

You might want to try lifting once and a while.

ca993twin

My guess: you have two separate, independent problems. You have a broken odometer gear (very common and easily fixed), and an electronic issue affecting the speedometer and the display. I can't help with the second one.

C4SJOHN

SLOW DOWN!

SchnellAuto

i may be wrong....but isnt that speedo runs on a magnetic pulse from the tranny? so if the magnet fell off..i have seen this happen..no speed ..but there is speed..most likely not..its the gear housing..or the gear are bad. the electric part has to be put on a oscilloscope ..

it may be cheaper to find a used speedo..

lemon

zenithblue993

Thank you people for the slow down response lol. But seriously, I think I can fix the odometer, but with the speedometer electrical issue, do you think it's part of the speedometer unit itself? Or could it be a wire inside the car giving off the wrong mph?
Thanks

zenithblue993

Would that magnet be inside the speedometer unit? If I buy a replacement spedo, I'm hopeing it would fix both problems. I'm just nervous that the problem is outside the spedo. Thanks!

SchnellAuto

the magnet is outside the tranny...connected with two wires...

frf

Besides the OBC not working properly, has the spoiler stopped working and its light is on in the center console? If so, and the ABS system is working without problems (ABS light off), that's pretty much an electric problem which I already faced, due to a malfunction in the speedometer itself - when ground connected all the speed signal received was vanishing. And forget the silly advices about tranny connected magnets - this is only used for information in Tiptronic equipped cars, the speed signal to the speedometer is provided by the ABS system using the information from the rear left wheel ABS sensor (at least in ROW cars, and I think, but I'm not sure, that in US cars from one of the front ABS sensors). In my case the easiest solution was to replace the speedometer but, it could have been fixed. Resuming, the ABS system provides the speedometer speed information, then the speedometer passes it to the OBC and the spoiler controller. That's why I asked in first place if OBC and the spoiler are working.

zenithblue993

I'm not to sure if the spoiler has stopped working, I've never really paid attention to it. But the light is not lit up at all. Also my car is an automatic with tiptronic so if that plays a role. I feel like buying a used one on ebay for 350 would hopefully fix it. It's just weird that the computer below the rpm gadge is giving wrong miles till empty, and mph. Do you think the mph is connected to the speedo gauge? Thanks for the detailed response

frf

The information for the speed in the OBC is provided via the Speedometer so, if this one is faulty the OBC speed does not display correctly or at all.

993GT

IMHO...circuit board inside the gauge is fried, just dealt with one...

zenithblue993

Are you taking about the on board computer/rpm gauge or the speedometer gauge? What did you do to fix or did you have to just replace it