Over the past 2.5 months I noticed that the TPMS sensor has been tripped, which never happened before. Initially I shrugged my shoulders and attributed it to the weather, refilled at a local pump to 34 PSI (verified with a gauge). But the sensor was tripped 2 weeks later, and before refilling I checked the pressures suspecting there was a leak in one of the tires. To my surprise, all of the pressures were low - ranging from 27 to 30 PSI. This would repeat itself every two weeks, and I could not find an offending tire - all 4 would be at least 5 PSI lower that original 34 PSI. Fed up with looking at the little TPMS butt light & with freezing my behind while pumping air in the tires every week, I made a dealership appointment for today deciding to just bypass the tire shop. They sprayed the tires with soap/water, found no leaks and pumped the tires back to 35 PSI.

Back to the drawing board, as I fully expect the problem to return. I drive on NYC's potholey roads and know it can affect the integrity of the rims and there could be microleaks through the rims. If it's the rims then this is upsetting as they should be able to hold up to this sort of wear and tear. I don't drive like a maniac and the tires are 1.5 years old, were properly balanced and rotated, AFAIK. It is also possible that salt/grime corroded the weights/rim internal surfaces and they may need to be sanded down and covered with a sealant at a tire shop. What are the next steps I should take (besides waiting, of course)?

 

Did they check the valve stems? It is your most common suspect.

 

If you have no leaks then you should know like you said that when the cold weather comes around, expect your pressure to drop and sensors to read 3-4psi below what they would be in warm weather, after a 20min drive you should gain the 2-3psi back once the tires warm up, i have the AM pressure sensors that show me the exact psi and temp in each tire, in the WINTER(like now) when i shut off my car after reaching home they will be at 35-36psi and when i start it in the cold morning its around 32-33psi but quickly get back into 35-36 when i get to work. As is u should expect to loose some air over time in cooler weather especially in NY winters.

That is why its recommended that you check and refill air when tires are cold, else fill an extra 2-3psi if warm.

hope it helps.

 

They did (and my regular mechanic did as well) - both said stems were fine If it was valve stem related, would think the leak would be in one - maybe two tires, but all four?

 

IIRC, I filled the tires when they were pretty cold to 34 PSI several times. It still does not explain how the pressure would fall from 34 to 26-27 in less than 1 week. Too big of a drop IMO to be accounted for the weather and temp-related air expansion/contraction. By the same token, the sensor light should disappear after 1 hour of highway driving (I have a long commute) as the heat expands the air within tires - but it doesn't turn off. What also concerns me is that nothing like this ever happened during the previous winter(s) - in fact, I've never seen the TPMS light prior to the past 2.5 months.

 

If all of your tires are losing a little air over a period of time, I would suspect a slow leak between the tire and the rim. There is usually a buildup of corrosion at the bead area of the rim, due to the reaction of the aluminum to the rubber. You can also see this on some cars when the center cap and the wheel are dissimilar materials. If that is, in fact, the case, the tire will have to be dismounted and the rim cleaned with something like an air powered scuff pad. Occasionally, the tire will also have to be cleaned.

I have one tire that is doing that now but it hasn't become enough of a PITA to have it fixed right now. I did have an older Intrepid that had to have all four tires done at least twice a year.

Mike

 

^ since its losing that much air and its not the stem or a puncture anywhere on the tires, it has to be the contact point of the rim and tire as mikeb suggested, or the potholes might have bent the rim the slightest bit to allow a very slow air leak when you hit bumps. The only way to check for sure would be to dismount a tire and have them check the contact path of the rim and tire and the integrity of the rim itself.

 

Remember that girl that you pissed off 3 weeks ago? Well she put bobby pin sized holes in all 4 your tires.

 

chances are...you're in single digits and below freezing weather in NY. That should explain basically the lost in tire pressure. I've lost about 10psi in mine when the temperature dropped from high 30's to the teens. I heard nitrogen maintains pressure more consistently if you want to try that.

 

The chance of all 4 rims or all 4 tires have a leak or all 4 bent is with quick calculations comes to 1: 23455595 +/- 2.

Well I think if all 4 tires doing it than it is the installation of the tires or the tires itself. Out of couriosity what tires you have? As you said maybe good idea to visit your tireshop and get them to re install the tires and the mean time to spray some sealants on them. How much tread you have left on them? Maybe good idea to switch to new ones.

From the last 4 winters with the G my pressure really dropped only 4-5 psi when it got cold each year.

 

Thanks everybody for chiming in with ideas and suggestions. The I have Goodyear Eagle GT's which were originally installed by a local Goodyear tire shop 1.5 years ago. I had the tires rebalanced a year after what turned out L front tire created steering wheel vibration at high speed (possibly after I curbed it or hit a pothole). I still have a decent amount of thread (50%) left and the tires themselves are not too bad in snow and rain - don't want to drop another $500+ to replace them way before time. Going to a tire shop and having the tires dismounted & rims checked for integrity/ clean and apply sealant is probably my next step. If the rims are kaput, will use it as an excuse to go up to coupe 19's by the winter's end, and possibly biting the bullet and getting one of those portable cig lighter compressors and just carrying it the trunk for a quick air refill.

 

My wife is pissed at me 1/2 the time, she knows how much I luv my G so it must be her

 

A week later, as expected, TPMS light went on. All 4 tires were at 35 PSI 6 days ago, now are 31/31/30/27. Having the tire shop de-mount tires, clean up the rims, reseal and remount. Hopefully this'll take care of it.

 

^ very weird, keep us posted.

 

As I thought, it was the rim corrosion. The guy at the tire shop said there was a _lot_ of corrosion on my stock 17" rims, and that leads to moisture trap -> oxidation. When the temperatures change, cracks form and rim/tire seal is compromised. He said that he had several Nissans and Infinitis with this issue - but it is common to many alloy rotors. They cleaned up the corroded rim and applied sealant, so I should be good for a while.