Solved: OXS related ticking sound from the dashboard of 911 SC
 

I was able to resolve the ticking sound from the instrument panel. It sounded like speedometer related as it would get faster with speed. Through the forum I found that it is OXS related and that it can be solved by disconnecting the OXS behind the speedometer. Since I am a total newbie, just purchased 1982 911 SC 5 days ago, I had no idea what OXS is. So to give back I am posting a photo of OSX and the wire I disconnected to stop the annoying ticking.

http://forums.pelicanparts.com/uploa...1496114680.jpg

That noise is normal. It's the doomsday counter for 30K miles, then your OXS light turns on reminding you to switch out the O2 sensor. That big white button in the picture resets it.

Thanks for that. Perhaps I should read the user manual first. Can you please tell me what is OXS for and do I need it?

OXS refers to the catalytic converter exhaust system. There is an oxygen sensor (OXS) mounted in your catalytic converter.

Back in the early 80's they did not have the check engine light monitor systems like today. So to comply with the EPA regulations for making sure the oxygen sensor was checked professionally Porsche installed the mileage counter. Light goes on after 30k miles, take it to the dealer for a checkup.

Do not mess with the real oxygen sensor. The warning system, fine to leave unplugged.

Thank you very much for that Bob. I will plug it back in and reset every 30k

Please let me know how you got to the sensor to reset it

Remove the speedo and you will see the box which I believe has two round cylinders on top. One of those has a Grey/white plastic plunger in it. Press it down with with a long screwdriver and it will lightly click. The light will now be off, illuminating only when key is on when other warning lights come on during startup. The clicking can get annoying but I like my stuff working the way it should so I stick with it

Pull speedo. Grab chop stick. Poke reset button. Perform fist pump.

You made me feel good for posting this thread. Pull the speedometer (really just grab it with your hand and wiggle it slowly) the counter is about six inches behind it.

Freak it's annoying listening to that tick. I thought I had a rock in my tire thread.😃

Bringing the thread back !
I have an '82 SC coupe. The ticking (noticed it a few years ago while sitting at a light) sounded like it was coming from the drivers side door and I've had the door panel apart looking for the problem.

Anyway, on a drive this weekend I noticed the OX2 light had came on at some point. The O2 sensor is only 4 months old and a Porsche brand.
I removed the speedometer gauge, found the mileage counter, and pressed the white reset button, with a thin wooden dowl. No matter how hard its pressed nothing happens. Could the counter not be tripped yet ?
The white button seems almost flush with the box.

Taking the box out would be very time consuming.
In all the years of reading and flipping through the Bentley manual I've never heard tale of this mileage counter. eh, you learn something everyday.

If any Pelicans have run into this depressed white button please let me know.
Thanks guys,
Josh P

does the white "reset" button need to be pressed while the engine is on or not? it seems you all missing to give this information

If I remember correctly, the last time I did it, the engine was off.