Low Tire Pressure Warning

[vt1912]

I noticed front right tire pressure was showing 26 psi and the other three 42 (normal). I didn't find any sharp object. Filled up to 42 and drove 40 miles. Pressure is still holding at 42 (it's been about 5 hours since fill-up) Tesla Support desk said just keep monitoring; it might be just cold temperature. But that doesn't sound right. It wasn't that cold this AM (45 F at lowest) and why would it have only one tire affected by temperature (and dropping 16 psi seems extreme, no matter how cold). I am going to take it into service but if there is no obvious external damage (nail) what could be the cause? (tire is Continental ProContact 255 45R19)

 

[Gadget63]

I've had that problem too when the temperature drops. in 70 degree weather the tire pressure was 42, but the next morning when the temperature was in the 40's I got the same warning. If the outside temperature is expected to rise, then I wouldn't worry about it

 

[tldickerson]

Somebody playing with your tires maybe?

 

[JoeT21MY]

16 PSI loss is too extreme. I went from 42 to 40 when the Chicago temps fell below 32F. Hopefully Service will find it. Did you have Sentry mode on to confirm no practical joke?

 

[GtiMart]

Rule of thumb is 1 psi change per 10F difference. It would apply evenly on all four tires. You might have had one tire underinflated, and because temperatures got lower it tripped the alarm. In such a case, there's nothing else to do.

 

[jcanoe]

Check that the tire valve is not leaking air. Unscrew the dust cap and put some soapy water (or just use some spittle) on the exposed valve core. If a bubble starts to form then the valve core needs to be tightened, else removed and cleaned or just replaced.

If it is not too cold you can mix a solution of dishwashing detergent and water in a spray bottle and spray around the rim of the wheel; look for any bubbles that start to form. This won't help you find a leaking tire seal on the inside of the wheel facing the brake rotor. For that you would need to remove the wheel with the tire and dunk it is a water tank to check for the source of any leak. (Tire shops have this type of water tank.)

Only attempt to remove the valve core if you have the proper valve core tool and a replacement core (these can be found at any auto parts store.) Also, you will need an air pump as the tire will quickly lose any remaining air when you remove the valve core.