I have a leak in the seal around the stem (see red arrow in picture). Can someone tell me if this will require a whole new stem with the monitor attached, or would I be able to just unbolt the top portion of it (the bolt at the bottom of the red arrow)?

 

I just got my tires rotated. My two front valves have been leaking for over a year. I brought to the dealer twice and they claimed that they could not find anything, and attributed it to porous rims, which they could replace at $500/each.

I told the tire mechanic when I was getting the tires rotated and now I have three leaky stems.

My neighbor has the same car 2008 Honda Civic Hybrid and hers too has leaky stems.

Sounds like a common problem.