Mystery click behind dashboard/gauges.
 

(For the search police, I did, with a variety of keywords.)

I'm hearing a fairly soft click from behind the gauges while driving the car. It sounds like a relay or possibly the turn signals self cancelling, except that the turn signals aren't on and it happens going straight. I'd say the click happens about every 5 to 10 minutes while I'm driving.

Any ideas?

I have an '83 SC but mine seems to occur more frequently than 5-10 sec. I originally thought it was mechanical - a bearing or wheel. Realized that when I turned off the car and it continued to roll the click went away. When I concluded it was electrical I quit worrying about it. I suspect it is some relay.

You may be hearing the o2 sensor notification clicking ... it should light up the bulb on the dash but it could be that the bulb is out ...

Not saying for sure that that is it with out hearing the click but its worth looking into ....

Another click you can sometimes hear is the odo if the gear is clashing slightly before it goes .. that would go with the vehicle speed .. more rapidly when faster and non when standing still ....

The glass in the gauge's expands and contracts and makes a click also.

My 83 SC also does similar. I hear it only when driving --- tick/click at 5 sec intervals (approx). Don't hear any thing when engine is shut down.

Im interested too. Sounds like mine, small click about 10 min apart. its almost like a small pebble bouncing of the windshield. I figured it was something in the heater system expanding under the dash.

Emergency brake warning light
 

In my car, this "clicking" sound turned out to be a bad emergency light switch on the MS. When the brake is engaged, there is a flashing warning light accompanied by a "clicking" sound. When the brake is released, the warning light should go off and the click should stop. If you do a search on this topic, you should find a fix that can eliminate emergency brake-related clicking sounds that involves disconnecting the battery IIRC. If this doesn't solve the issue (and it didn't in my case), you may have a bad e-light relay on the MS.

That is the o2 sensor counter for sure. Take out the tach. and you'll see it and unplug if you wish.

If the reset knobs for the Odo and the clock contact the side of the hole through the glass they can make a click. Also as mentioned before, the glass can make that sound against the bezel. Grab the bezel of the gauges and see if tweaking them a bit makes the same click. Releasing the built up force will also prevent it for clicking for a while. My clock does this fairly regularly...

Mine does this.

I've got the mystery click in my '88 as well...the 5 - 10 minute interval one. Hearing this has been a part of the driving experience since I've owned the car. I always thought it came from the clock. Had the odometer gears replaced by North Hollywood Speedometer and this didn't change the click in any way - still there. Replaced O2 sensor around 8000 miles ago and that had no effect on the click.

The tonal quality of my click sounds exactly like a small stone hitting one of the instrument glass faces...kind of has a sharp tick with "cup" like overtones, exactly what would eminate from inside one of the instruments.

Tiny German midget throwing rocks inside the clock?

Which bulb would it light up? I'm looking in the owner's manual and I see no reference to that. Is this some sort of early attempt at a CEL?

In any event, in my case the click is every 5 to 10 minutes so that doesn't sound like the case. Also, I thought about the odometer and I've watched it tick over both tenths and full miles. It seems to be quiet and smooth.

Don't get me wrong, I attribute the whole thing to character.

It goes along with the time that I was driving it in a fairly back woods part of NH and gas gauge seemed lower than it should be. I tapped the glass like the WWII fighter pilots do in the movies and the gauge jumped to where it should have been. I was very pleased that I fixed something.

You've acquired the notorious "Neun-elfer"
..or rocks inside a clock...
German Elves

Read my lips ITS THE GLASS!

I love the click. It's like a reality check: you're in the 911, things are good.

Mine's every 5-10 min, even did it over the winter with the battery out of the car.

Dang! Mine does it too. Every few minutes when driving. Seems to come from the dash. I thought mine was the only one that did it. Blimey!

Yep, mine too. +1 on the "expansion". Almost certain it's the gauges...

I don't have an O2 sensor..

not sure about the 5-10 minute version but on my SC it was the OBX sensor/box thing behind the dash clicking every few seconds. there is a reset button on it, or you can just disconnect the ground wire and it will go away.

It's the glass/plastic from the clock expanding/contracting. The sound seems to come from the center hole where the adjustment shaft sits.

jp
NY