Recently had my Rota GForce 18x9s mounted and balanced to Falken FK452 245/35-18s with OEM TPMS Sensors. I had the Mazda Dealer mount the TPMS and had a tech where I work mount the tires. I recenetly have been loosing air in all four wheels. I can literally hook up our guage after filling to 42psi and watch it drop down in small 1/10 psi increments. I am now topping these daily to avoid running to low and damaging the belts or wheels..any ideas or suggestions?

 

Improperly mounted TPMS i'd say.

 

One thing I tried simply because I assumed the same thing...I tightened them down a bit more but I'm still leaking out air at a good rate...I know they're only Rotas...but they are better than stocks

 

Any tire shop should have one of these: Lisle Plastics 19822 TIRE DUNK TANK

 

I had this issue on one corner a few years ago when I got new rims and tires. Not the best idea but I was able to find a rubber grommet that fit tightly around the valve stem and worked it into the space between the valve stem and the rim........before putting the cap on. Once the cap was screwed down it cured my issue. Next time I changed tires and at that time I went ahead and put in new TPMS and had no issues this time.
Think I has a thread on it somewhere, let's see if I can find it. Couldn't find thread, but found pic that was in the thread.

The red grommet is the original on the TPMS and is inside the rim.
The 2nd grommet/gasket(in yellow) is what I added. It was added and wedged in there while everything but the cap was on the wheel.

 

Where could I possibly look into getting some of the yellow grommets? I can already tell this is going to be a pain in the *** having to pull every tire off but for a few hours work I wont have the dumb light on anymore...

 

Weren't really yellow, I just colored them for the picture.

Anyway, I actually went and bought a box of tire valves stems at Autozone.
I just asked the guy what he had and looked until I found a box with what I thought were the right size grommets. I didn't care about all the other stuff, the schrader valve etc., I was only really after the grommets.

I'll see if I can get some info off the box or take a pic of it. The real way to do it would be to go back to your shop and have them mount the TPMS's correctly. Of course this assumes the TPMS's will fit on your rims.

My problem was that the hole in the rim was bigger around than "normal" and the grommet on the TPMS, which is on the inside of the rim(red in pic) was not enough to keep air from escaping.

If you end up using my method, you won't even have to pull the tire off or take the wheel off. Just take the valve nut off(blue in pic), wedge the new grommet(yellow in pic) into the hole around the valve stem being careful not to let the valve stem fall inside the tire........and work the "new" 2nd grommet down as far as you can, then replace the valve nut. The valve nut will actually compress the grommet and may make a good seal...................it did for me.

 

Check that your valve cores are tight. Had this issue once when I got new tires. Cores were loose so all my tires were leaking. Tightening fixed the issue.