c. e. white

I have a strange tire problem......

I have a 2011 Ford Fiesta, purchased new in late February of 2011. It is the
SE Hatchback (not SFE) with Kumho Solus KH25 185/60-15 tires on alloy
wheels. For the first 5 months I added air to the tires once (and I did
check them regualrly). In late July, out of the blue, the low tire pressure
warning light came on when I was on the way to work. I was afraid I had a
tire going down, but the car drove normally so I continued on to work. As
soon as I got to work I looked at the tires and all appeared normal. When I
got home and checked, the pressure in all four tires was in the mid-20s.
Weird. I reinflated all the tires to 35 psi. All seemed fine for the next 3
weeks or so, until yesterday. The low tire pressure light illuminated on the
way to work again. As before when I looked, the tires seemed fine. As
before, when I checked the pressure, 3 of the 4 were in the mid 20s, one was
in the low 20s. I reinflated the tires to 35 again. I've had a lot of cars
and a lot of tires, and never before have I had a set of tires (four tires,
not just one) lose 10 pounds of pressure in less than a month.

Any thoughts? My only thought is that I somehow damaged the tires on a mid
July trip to Florida. We drove I-95 to South Florida in mid July. The trips
were quick (600 miles, <10 hours including stops). Is it possible I somehow
damage the tire structures in such a way that all four are now uniformly
(more or less) leaking air at a much higher rate than normal? Parts of I-95
are really rough, it was really hot, and the trip to Florida and back was
fairly relentless.

Ed

sc tom

Some evening (when it's a little cooler out) after driving around for a
while until the tires are good and hot, take a small brush and brush a
liberal amount of water and dish soap solution around the bead areas and the
valve stem (both on the filler valve area and the seal at the rim) and see
if any bubbles form. It may take a little while since the leak is very slow.
I've had leaks before where the filler valve had worked loose just enough to
leak out the way you describe, but I've also seen leaks around the bead
area, but usually on older rims than you have.
--
SC Tom

c. e. white

I've had one fail like youu are suggesting.....but all four at the same
time?

Ed

sc tom

LOL, no, not all four. But maybe with the extreme heat of the Florida trip,
maybe the stems loosened some? Those aren't the tires that cam on the
Fiesta, are they? Or did it come with Kumho's on it? It would be awfully
hard to prove, but maybe some damage from the installer? Still hard to make
it all four tires/rims though.

Good luck with it. Let us know whatever the resolution is.
--
SC Tom

c. e. white

Kumhos are the original equipment tires on 2011 SE Fiestas. The car has the
Ford valve stem attached style of pressure transducers with the replaceable
rubber valve stems. I have had the same style on two other Fords and never
had a problem with the stems or tires - but then I never drove back and
forth to Florida in 100 degree July weather with those vehicles.

The Kumho tires seem decent. At 15K they still look good, don't bump and
seem grippy enough for NC weather (little snow!). But this realtively fast
air leaking has be baffled. I guess I need to check them at least weekly
(they never have "looked" under inflated).

Ed

jim beam

there's a very limited number of possible causes, so let's consider:

* tires. they're multi-layer, and there are several features designed
to help air retention. one is the bead that contacts the rim. another
is the butyl rubber liner that decreases air permeability. if either of
those have been cheapened, and if you look, you'll see those tires are
made in china, they will indeed lose pressure faster than you're used to.

* valves and valve stems. the mold seam sealing surface is crucial to
airtightness, and it's easy to screw up with a poor quality molding
machine. same for the seal bands on the valve.

* the rims. while unlikely, rims, especially cheap cast aluminum, can
be porous.

you could also of course have a flat - a staple on the freeway will
explain the single "flattest" tire but still be hard to spot.

but the reason they're all losing air so fast, for my money is either
tires of valves. you can have the latter replaced cheaply enough. if
it's the tires, and it's bugging you bad enough, you'll have to replace
them. get stuff that's not made in china where they cut corners and use
unskilled labor, and you'll be fine.


--
nomina rutrum rutrum

If they are OEM tires go back to the dealer and see what they have to
say - the car (and tires)is stil under warranty.

iym

All the suggestions given to you are viable that you should check out,
but I'd personally *lean* towards the valve stems...at least as the
first and cheapest thing to go after. I had the same problem as you,
although not with the OEM tires. every time I'd check, they all would
be down. I let it go, and then one day I came out and one tire was
completely flat. I took it off the car and brought it to a tire shop
and they said the stem was no good. Put it back on the car and no more
problems...from that tire. The other three kept losing air. So I took
the car down to the shop and they replaced the remaining 3 stems and I
haven't had a problem since. Funny thing was, the guy asked if I got
the tires (set of 4 Michelin) from BJ's. Surprised, I said 'yes' and he
said he had gotten a lot of people with the same issue in lately. He
said they must have gotten a bad/cheap batch of stems. With yours, I
suspect the car and tires are still under warranty? Bring it back to
the dealer and let them take care of it. Heck, you may even get a new
set of tires out of the deal...They might also have experianced a bunch
of customers with the same issue as you...

steve w.

A 2011 having this problem should have the first step of taking it back
to the dealer and having them check it out. Having ALL of the tires drop
evenly suggests a fault that should be covered.

--
Steve W.

c. e. white

The Ford warranty covers the tires. The amount covered depends on the
mileage. I am past the 12,000 mile mark (100% covered till then), but in
theory Ford will cover 60% of the cost of the tires, if the problem is the
tires (at least till I hit 24,000). And the tires may have a manufacturer's
warranty as well. But, I suppose I'll need a little more history before I
try to get Ford to do anything. I'll monitor the tires for a couple of weeks
and if they still seem to be losing pressure at an unusal rate, I'll visit
the dealer. I can't imagine this will be an easy sell, but you never know.

Ed