I have a strange clicking sound under the dash when moving. Does not seem to be tied to engine/trans.

clicks accelerate/decelerate with wheel speed. Click is also accompanied by a blip in the aux gauges (all of them in sync blip up/down slightly with the click).

any thoughts?

https://youtube.com/shorts/9a2DiIoXHBw?si=2fdSqPCSib6KNyR8

 

Sounds like the O2 counter in the carpeted box between the passenger seat and door. Most people just unplug it.

 

Def not 02 counter - it is unplugged.

I had replaced the odo gear about 20k ago, but…

Wayne suggested there may be a link there. Well when I stopped at a light I reset the odo - the gauges dipped a bit when I pressed the reset and the voltage dropped a LOT…like a short maybe somewhere in the reset circuit. I do have the lutz boards on my gauges.

 

Is your odo still working?

 

Yep no issues with odo and trip odo resets and works just fine

 

My 80 Euro did this originally. It was a failed aftermarket relay that was installed to give the car a seat belt warning buzzer. Apparently it was required during federalization.

All my 928s exhibit similar behavior on odometer reset. The solenoid VDO used in these clusters are way overpowered and violently yank at the odometer reset bar

 

Well - I thought the switch was the issue but it turns out it is not. The click is still there along with the gauge blip - even with the switch removed. Somehow somewhere something is being grounded at a regular interval that is directly connected to speed of a wheel turning - and it is showing its path in one of the cluster grounds. I guess the next step is to get the car off the ground and start the engine and go around and see if we can determine the source of the grounding by manually turning each wheel and watching the gauges of listening for the click.