From: xenolith@optusnet.com.au   
      
   On 25/7/2022 10:59 am, The Real Bev wrote:   
   > On 7/24/22 5:45 PM, Paul in Houston TX wrote:   
   >> The Real Bev wrote:   
   >>> 2013 Corolla S with the original wheels, tires and pressure sensors.   
   >>> There are only 33K miles on the tires and the tread is just fine.Ever   
   >>> since I've had it (2016) a single tire loses air very slowly -- it   
   >>> used to go from 32 (or 35, I'm not real picky) down to maybe 24, and   
   >>> the light would come on.  A month or so later the same thing   
   >>> happened.  Time between lights is now between one and two weeks.   
   >>>   
   >>> Dealer said he couldn't see a problem.  (I have no actual proof that   
   >>> he actually looked.)  I have a nice plug-in tire pump (the $35 one   
   >>> from Harbor Freight;  the cheaper one burned up rather quickly when I   
   >>> tried to pump all four tires) so there's no real problem, and I'm   
   >>> unwilling to load the tire up with slime, but I'd really like to know   
   >>> WTF is happening.  Sooner or later I'm going to need new tires and it   
   >>> would be nice to know if I need a new pressure sensor too.   
   >>>   
   >>> BTW, I really like the tires (Goodyear Eagle RS-A) -- excellent   
   >>> cornering on the road I take to go skiing.  People really need to be   
   >>> ashamed when they get passed by a granny in a 9-YO Corolla!   
   >>   
   >> If the manual tire gauge agrees with the pressure sensor then the   
   >> pressure sensor is ok.   
   >   
   > The red light just says I NEED AIR.  The gauge on the pump and on my   
   > nifty little talking digital one are never the same -- I've NEVER seen   
   > two gauges the same, in fact.  For one reason, you lose a little air   
   > each time you check.  I wonder if the sensor device itself has a tiny leak.   
   >   
   > Some of the tires have plastic caps, some not. I had a cap on this one   
   > originally, but I lost it a while back.  No difference.  I keep meaning   
   > to buy some of the metal ones with the core tool, but I forget.   
   >   
   >> You did not say if it is always the Same tire -   
   >> will assume so.   
   >   
   > Yes.  The others hold air for months with or without cap.   
   >   
   >> Every time I had that problem there has been a nail or screw in the   
   >> tread.  The left rear of my Kia had that problem for last two years and   
   >> I finally upped the air pressure to 40+ and soaped it.  Found the screw   
   >> and removed it with needle nose pliers and then plugged it.   
   >   
   > I'm sure that if the dealer (amazingly enough, and against everything I   
   > knew about buying used cars for the last 50 years, I bought the car from   
   > the dealer, and it was the first one I drove when I decided on a 2- or   
   > 3-YO Corolla -- I couldn't see a reason to NOT buy this one!) would have   
   > found something obvious if he'd bothered to look.  They used to do a   
   > free rotation with the discounted oil change, so there's really no   
   > reason he shouldn't have given it a visual inspection;  I didn't expect   
   > them to take it off the rim.   
   >   
   >   
   A *visual inspection in-situ* will not find a slow leak. All that is   
   doing is a scan for the obvious, like a *visible nail*. To do a proper   
   inspection for a slow leak, you really need to remove the wheel and do   
   an immersion test. A pressure leak that loses ~10psi over a week will   
   show as a bubble every now and then during the test. When I was a wee   
   apprentice, we had a water vat purely for the purpose of leak testing   
   tyres. The practice works.   
      
   FWIW, your tyres are getting to the point where I would call them *time   
   expired* or, as they say, past their *use by date*. I have never had the   
   issue of tyres time expired, they are typically worn out in 3 to 5   
   years. I'd clock up 33 k miles in 2 years, maximum 3, so I've never seen   
   a tyre on any of my cars over 5 years old.   
      
   --   
   Xeno   
      
      
   Nothing astonishes Noddy so much as common sense and plain dealing.   
          (with apologies to Ralph Waldo Emerson)   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)