Loose TPMS valve stems.
I just saw the following post by J. Cox on Lucid Owners FB:
"Hello, fellow Lucid owners!
I have an Alert Bulletin (AB) for you all to look out for on your Lucids. In aviation, pilots and mechanics identify potential problems, and then they issue what's called an Alert Bulletin (AB) so that everyone in the industry can be made aware of a potential problem with that particular aircraft or system, so then everyone can identify and eliminate potential future accidents.
So I figured it was fitting since we all drive Lucid (“Air’s”). Definitely not looking to catastrophize this, as it’s a minor inconvenience and something you can have them do on the next scheduled maintenance. Anyway... If you’re mechanically inclined, you can easily DIY inspect this problem on your Lucid Air and/or Gravity at home. If you’re not so good with tools, then be sure to request to get checked during your next mobile service or at your local Lucid Service Center. Also, any tire shop like America's Tires will be able to check this for you for a minimal fee or probably even for free as well.
Anyways, on to the story, today while out and about in a friend’s Lucid, we drove to the local supermarket. While shopping for about 30 minutes, he had a warning pop up on his mobile app that the front right tire pressure was low. (Showing 45 psi. Normal pressure should be 49 psi with the 19" Aero Range Wheels.) After a quick inspection for screws or nails, we found nothing. Well, after we pulled out of the parking lot on our way home, we were watching the TPMS pressure on the pilot panel drop quickly (like a stone). Realizing we were not going to make it back, we pulled into a gas station to air up the tire. (FYI, in California, both air and water are free at all gas stations. Just simply ask the attendant to turn it on.)
Much to our surprise and fear, the tire made it down from the already low 45 psi to just 22 psi in less than 5 minutes of driving. (Approximately 1-2 miles.) We pulled the Aero Range cover off and found that the TPMS valve stem nut was barely hanging on by just a few threads, and the whole valve stem was loose and hissing air when touched. We ran the nut down by hand the best we could, then we inflated the tire slightly above the door sticker rating (only to make sure we could make it home with a rapidly leaking tire).
On the ride home, the tire only dropped by 2 psi. (Approximately 7 miles.) I looked up the Lucid OEM TPMS valve stem nut torque spec, and it is 53 +/- 6in-lbs.
Here is the thing... All 4 TPMS valve stem nuts were practically hand-tight on the Lucid we were driving (which admittedly has 75K miles on it). But each TPMS sensor was 1 full rotation or more loose from torque. We then checked the valve stem nuts on the Green Air GTP. All 4 of them were loose as well. Then we went down and checked the valve stem nuts on the other Red Air GT, and it also had 2 loose nuts on it.
The other two cars were not as loose, and all hold air like normal, but they also don't have as many miles of use as the daily driver, Lucid GT. Out of 12 tires checked, only 2 were within torque. I highly recommend you all check your TPMS sensor valve stem nuts for proper torque.
--The torque value on the Lucid OEM valve stem nuts is 53 +/- 6in-lbs. With the use of a 7/16 or a 11mm deep socket.--
If those nuts become loose and/or fall off, your tires could rapidly deflate, getting you stuck somewhere waiting for the heroic Lucid Customer Care team. So, with that said, I highly recommend you check your TPMS valve stem nuts for proper torque."
