Slow Leak in Tire Pressure When Cold --Not Tire

[jnonny]

I'm having a strange slow loss of pressure in one of my front tires ..and was wondering if anyone may have had similar experiences..

I've had three visits to the Dealer now, and last visit we changed the tire, but still leaks when temps drop below 30F or so ..otherwise seems to hold air fine for weeks..
..

It all started when I noticed the tire pressure light come on a couple times through the fall --didn't think much of it, just attributed it to normal fluctuations with temp/time, etc.. as was a good deal of time passing between --just topped off the tires and carried on..

The real problem arose when winter came and temps began to drop further.. the first "cold" day when temps dropped below 30F I came out to a flat tire one morning --figured it was a nail/puncture ..filled the tire and proceeded to look for a nail..

Couldn't find any nail, so removed the tire, over filled it to 50 psi or so and sprayed the tire with water to search for bubbles and signs of the leak/puncture --but to my surprise could not find any signs of a leak --did this a few times and no sign of leak..

So figured it might be the TPM sensor/valve or rim.. and/or may just be missing the puncture.. The dealer isn’t too far from me so I figured I'd have them take a look..

Dealer visit one:
Dealer removes tire, puts extra pressure and dunks the tire in a tank of water to look for bubbles --nothing.. They can't find any sign of a leak.. They then tighten the TPM nut and then remove the clip-on weights and replace them with the stick on type ..indicating that possibly there may be a compromised seal due to the clip.. Sounds good.. A week or so goes by and all is well.. until the temp drops below 30, and once again had a flat overnight..

Dealer visit two:
I relay the problem, that the tire only leaks when cold (<30F) and holds air fine otherwise ..I tell them to just replace the tire if once again they can't find the leak.. (the tire was run for a bit w/low psi, resulting in some scuffing to the sidewalls so figured the tire should be replaced anyways) ..Once again, tire is overfilled and dunked, but no sign of leak --I'm then told that they had a similar issue recently where a tire was leaking from the rim/bead and that bead sealing compound fixed it (also indicating that there was a slight groove in the bead from prior weight clip).. They also indicate that they will replace the o-ring on the TPM sensor.. Further indicating that the tire is fine and does not need to be replaced.. Ok, sounds good to me.. the then remove tire and apply the bead sealing compound and replace o-ring.. and again all is well ...now seems to be holding air in temps below 30F.. until a really cold night in the teens comes along and once again I have a flat in the morning..

Dealer visit three:
I relay the problem again (only leaks when cold, etc..) and tell them to take a quick look again, but just change the tire as we seemed to exhaust all options last visit and I don't have time wait, return again, etc.. They return with the same can't find the leak.. and are hesitant to change the tire as there is no sign of leak –though also indicate that rim appears fine/perfect and TPMS again double checked.. I certainly don't want to have to pay for a tire if it does not need it, but they verified that the rim and TPM sensors showed no sign of issue/cause.. They wanted to swap the front tires/rims to see if leak follows tire and/or stays with the rim --but I can't keep returning to the dealer, etc.. so figuring the tire was the only variable based on their expertise, I had them just change the tire.. (They indicated that they would send the tire to the manufacturer to search for a defect in hopes of possible refund/reimbursement)

All is well for a few days until once again this morning (in the teens overnight w/snow) my TPM light came on and I was 10psi low.. Seems to be better once again as not completely flat this time ..but the leak is still there..

I've since called the Service dept and am waiting to hear back regarding warranty coverage for this issue, and what can be done now that we officially ruled out the tire.. They mentioned leaving the car for eval ..but don't want to return if not covered (don’t have the tire/wheel warranty) ..will see what they come up with --The Service team has been quite accommodating in attempting to fix my leak issue thus far, just figure three times for same issue is enough eval.. and if not covered will just order a rim/sensor and replace on my own..

Long story short (apologize for the rambling )..anyone have any strange tire pressure/leak issues and/or find the respective culprit.. any thoughts on the leak being the rim or TPMS..

[jetfuel]

...change the rim...aluminium reacts in weird ways to extreme temperatures...
...have them pull the tire and go inch by inch around the sealing area of the wheel..
...bet you a beer....there's an imperfection of the sealing area...my1c..

jetfuel

[jnonny]

Originally Posted by jetfuel

...change the rim...aluminium reacts in weird ways to extreme temperatures...
...have them pull the tire and go inch by inch around the sealing area of the wheel..
...bet you a beer....there's an imperfection of the sealing area...my1c..

jetfuel

..thanks, but forgot to mention that this is on a Pure with the Steel Rims --guess there could be an imperfection/defect with the steel rims as well?

and/or any chance of a good pot hole impact causing the rim to go slightly out of "round" --making it difficult for bead to seat properly when rubber contracts/stiffens with cold..

[jetfuel]

...the same applies...inch by inch inspection of the sealing area with the aid of a light that can be seen from outer space...lol

jetfuel

[smark]

If the dealer is far, just go to any tire store. You don’t have the tire/wheel warranty. Sound like a bad steel wheel. With a very slow leak. A bad seam in the wheel itself. Do they run soapy water around the wheel seams, and tire bead???? Good luck.

PS.
Check to see if the valve stem needle is screwed all the way in.

[wahi]

maybe one of the neighbor's kids?

[jetfuel]

Originally Posted by smark

Do they run soapy water around the wheel seams, and tire bead????

...if they do that get a towel and a gun...make him dry the whole tire and wheel assy and then shoot the bastard for being an idiot ...

jetfuel

[h20m0f0]

I just put air in my tire on the way home from work tonight, mine was just cuase of the wheather change (it's dipping into the 40's here Brrrrrrrr) so my tire light was coming on, but now it's all better no light all the way home....

[GHammerly]

My light came on today but garage = 45F , outside = -6F

[jnonny]

..appreciate the feedback ..Looks like the new tire is holding pressure now, no drop after a few days in the single digits and snow ..so looks like the tire was the problem..

might have jumped the gun after the tire was replaced ..initial drop must have been due to the drastic swing in temp from the heated garage at the dealer (70F) dropping to the low teens outside over night ..and/or the new bead might of had to "seat" in a bit..

will see, but looks like the new tire fixed my mysterious leak --still strange though as the old tire had no signs of any puncture and only leaked when cold (below 30 or so).. poss some bead/rim combination/defect and/or just a really tiny puncture with a decent seal until cold..