Last post on Feb 12, 2011 at 7:22 PM
You are in the Subaru Legacy & Outback
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Subaru Legacy, Subaru Outback, Sedan, Wagon
#14 of 34 Re: 2009 Subaru Legacy Limited - TPMS Light [pilot1226]
Feb 18, 2010 (7:38 am)
Service Papers in hand and pictures of the tires...
12/15/08 - 3750 mi service
04/14/09 - 7500 mi service (Tire Rotation)
04/16/09 - Passenger Rear Tire replaced (sidewall bubble)
07/24/09 - 11250 mi service
11/10/09 - 15000 mi service (Tire Rotation)
So, looking at the pictures:
Passenger Front: fdh4 nxf4907
Passenger Rear: fdh4 nxf4907*
Driver Rear: fdh4 nxf1908
Driver Front: fdh4 nxf4907
So, we can see that the Driver Rear tire is the one that was replaced as this DOT number matches my documentation from the shop where I replaced the tire. Given the 2 rotations, it appears that the replaced tire has followed the typical rotations per the Subaru owner's manual below:
Whether the dealer actually follows this or not, I don't know. I know that my previous car, a Civic, had a different rotation path even with non-directional tires.
So, it seems like between the two rotations, the passenger rear went to the driver front, then the driver rear where it is now.
This means that the tire with the persistent TPMS light was on the Driver Rear at the time the other had the sidewall bubble - on the other side of the car. So, to me, this rules out mauling a curb or the same pothole being the culprit. Again, a lot of this "theory" depends on whether or not they were rotated the way the owner's manual said, but so far, all my rotations have been done by the dealer. And, we ruled out that it's definitely not my new tire that's leaking, which is a relief.
I didn't see a nail or anything irregular in the treads themselves. Either way I'll have the dealer look at it when I take it in for the 18,750 mi service next week.
#15 of 34 Re: 2009 Subaru Legacy Limited - TPMS Light [pilot1226]
Feb 18, 2010 (10:42 am)
Either way I'll have the dealer look at it when I take it in for the 18,750 mi service next week.
Sounds like a good plan at this point.
#16 of 34 Re: 2009 Subaru Legacy Limited - TPMS Light [pilot1226]
Feb 18, 2010 (8:01 pm)
Now there's an interesting fun fact. Subaru has changed it's long standing tire rotation policy and now recommends cross-rotation??? In my previous post, I was advising you to follow what appears to be an outdated set of instructions.
From my owners manual:
Tire wear varies from wheel to wheel. To maximize the life of each tire
and ensure that the tires wear uniformly, it is best to rotate the tires every
7,500 miles (12,500 km). Rotating the tires involves switching the front
and rear tires on the right-hand side of the vehicle and similarly switching
the front and rear tires on the left-hand side of the vehicle. (Each tire
must be kept on its original side of the vehicle.)
#17 of 34 Re: 2009 Subaru Legacy Limited - TPMS Light [fibber2]
Mar 04, 2010 (5:49 pm)
Well, I had the car serviced today. They took the tire off and put it in a tire bath and basically came to the conclusion that there's no air escaping from it. So, I guess that's good news. No nail or any other irregular markings to suggest tire damage.
The dealer suggested that if I continue to have the issue that I take the car to a tire shop because they have some more advanced equipment.
Not sure if I asked this above, but is it possible for the Subaru TPMS system to "vent" when the pressure is too high? Reason I ask is because I'm wondering if the recent heat changes in my neck of the woods could contribute to the light coming on. (From weather in the 50's to the 20's).
Otherwise, I'll have to keep an eye on it. The light came on today while driving it to the dealer for service, but before that, it was good for about 2 weeks without filling it.
#18 of 34 Re: 2009 Subaru Legacy Limited - TPMS Light [pilot1226]
Mar 05, 2010 (5:42 am)
Not that I have ever heard. It is simply a monitor system, and not reactive.
I still think there is a leak somewhere. The problem with a tire bath is that it is a 'no-load' test. Your tire might only leak out a small amount of air during certain dynamic operations, such as hitting a bump or pothole, cornering loads that push against the bead, when hot and the internal pressure exceeds a certain threshold, etc.
It could be a rim problem, where the tire meets the rim, or the TPMS/valve unit itself.
#19 of 34 Re: 2009 Subaru Legacy Limited - TPMS Light [fibber2]
Mar 06, 2010 (9:27 am)
Okay, that makes sense. So, if I bring it to the shop where I had the one tire replaced (a Yokohama retailer nearby), what kind of test(s) should I be asking for, and what's a reasonable price for it?
#20 of 34 Re: 2009 Subaru Legacy Limited - TPMS Light [pilot1226]
Mar 06, 2010 (10:15 am)
I had a slow leak (1 lb/wk) on my 07 and took it to a tire place. They used a water bath and had trouble finding a leak, but finally found a leak around the tiny gasket used to attach the TPMS unit to the rim. They showed me where it was corroded, but not from rust.
They told me that the material the gasket was made of was reactive to the alloy wheels which caused corrosion and then a leak. They replaced the gasket with one of a different material. They said there was a Bulletin out on the problem.
I don't remember whether the new gasket was silicone or whether silicone was the one that was reactive to the wheels.
I later mentioned this to my Subaru dealer, and they were not aware of the problem.
We've also had slow leaks around the rim due to corrosion from the salt used on the roads here. I don't think your car is old enough for your leak to be due to this problem.
#21 of 34 Re: 2009 Subaru Legacy Limited - TPMS Light [snowbelter]
Jan 17, 2011 (1:57 pm)
Another winter is here and sure enough this same issue persists. Only in the colder months - when the temperature outside is around or below freezing (32F), the TPMS light will come on affecting the front two tires. This is persistant, despite rotations. I think there may be some type of problem with the Yokohama tire itself?
When I fill it to 33PSI cold, as the door jamb suggests, it lasts for about 2 days, then the light returns. It seems the front tires will "stable off" around 27PSI and won't lose any more air at this point.
The rear tires have been a solid 30PSI and don't require any air.
But, considering all the quarters I've put into air pumps at the local gas stations, I might as well have bought new tires by now.
Do I have to have the lower-profile tires with the Legacy, or is there a way to get a conventional tire profile for when I get these things replaced?
#22 of 34 Re: 2009 Subaru Legacy Limited - TPMS Light [pilot1226]
Jan 17, 2011 (7:24 pm)
That does seem odd. When the temperatures drop however, your air pressures will go down, causing the TPMS light to come on. I would pump em up to 35psi and see if they can stay stable.
Subaru Guru and Track Instructor
Jan 17, 2011 (8:13 pm)
According to TireRack.com, the Yokohamas on the Legacy are Yokohama Advan A82A (Ultra-High-Performance All Seasons) 205/50R17, V rated though I wouldn't be foolish enough to try to push 149mph in Northern Jersey, too much traffic!
Max inflation pressure is 44 psi, so I'm comfortable to inflating it to 35psi in that I won't pop them in highway driving as the pressure increases.
Since the light is on - again - I'll go and hit the nearby pump one last time and we'll see how long it lasts. Driving doesn't seem to affect it in anyway, so the only thing I can think of is some bad contact between the stem and the tube or something along those lines, but it's so weird because it only affects them when they're in the FRONT, meaning the pressure from the engine is really pushing on them.
At any rate, what are your opinions on Michelin Pilot Sport A/S Plus or Pilot Exalto A/S? The Sport Plus is a little bit more money ($10 per tire, give or take), but the treadwear is 500 as opposed to the 400 of the Sport Plus. The Sport Plus is also listed as High Performance, whereas the A/S is "ultra-high."
Thanks, will check back in a few days. If it weren't for this tire glitch, I would say the Legacy is a perfect car for my needs. (Though come spring we will be selling our Nissan and getting a new Outback!)