Hi all, the leaking occurs in the rear passenger tire. It leaks very slowly, I would say from 35tpms to 32tpms in 2 weeks. I drive every day. and no it doesn't have anything to do with temperature because it's the only tpms that goes down and I have checked all my tpms regularly.
I don't know whether the leak comes from the valve or from any bend of the wheel. Is there anyway I could do to pinpoint the leak?

Thanks in advance!

 

tires will naturally lose air pressure over the course of time. As they warm up the rubber molecules expand slightly and let out tiny amounts of air. Think of the tire as a balloon. After a week or so balloons start to deflate by themselves because the air is seeping out through the rubber.

However an excessive loss in air like you are having could be due to a few things.

1. Bad Valve Stem -> a tire shop can screw on a new one for a few dollars and call it a day.
2. Nail in tire/damage -> check your tires for a nail or any other sort of damage.
3. A bad seal on the tire -> if the tire is no longer sealed against the rim it can leak air every time you hit a bump (tire may have unsealed slightly/cracked the sealant bead after a hard hit). If this is the case, a simple dismount and remount should fix the problem.
4. A bent wheel -> a bent wheel will also cause the seal not to be 100% and allow air to leak.
5. A cracked wheel-> a small crack will allow air to escape, the tire place can check this in their water tank.

 

Also if someone uses fix-a-flat it can cause the next tire to not seat properly. Spray soapy water on the rim if there is a leak it will bubble on the spot.

 

thanks guys... I'll try to spot the leak !!!