Only one tire deflating tells you the leak is localized to that wheel - so check the four common spots: tread (nail), sidewall (puncture), valve stem, and bead seal between tire and rim. Most of these are $25-$60 fixes.
Picked up on the road. Often plugs itself partially and leaks slowly. Soapy-water test finds it instantly. Patch from the inside for $25-$40.
Aluminum wheel corroded where the tire seals. Most common on cars 5+ years old in salt-belt states. Visible as white powder on rim edge.
Rubber stem cracks at the base after 5-10 years. Aluminum stems corrode at the core. $5-$30 to replace.
Pothole damage opens a hairline crack invisible from outside. Inflate to 40 PSI and spray soapy water on the inside lip.
Rubber grommet that seals the TPMS sensor to the rim dries out and leaks. $20-$60 to replace the seal kit or sensor.
Curb strike or sharp object. Sidewall is not patchable - the tire must be replaced.
| What You Notice | Likely Diagnostic Step |
|---|---|
| Lose 5+ PSI overnight | Major leak - inspect immediately |
| Lose 2-3 PSI per week | Slow leak - patch or reseal |
| Lose air only in cold weather | Normal contraction - 1 PSI per 10F drop |
| Visible nail head | Pull and patch from inside, do not just plug |
| Same tire flat after each repair | Bead corrosion - needs proper reseal |
Tell us which tire, how fast it loses air, and any recent road hazards - we'll tell you the most likely cause.
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Because the cause is local to that wheel. Nail, valve, bead, or bent rim - all isolated to one tire. If multiple tires are leaking equally, it's pressure-temperature drop or normal permeation.
Short distance to a shop yes, if you keep it inflated to spec. Don't drive it flat - the sidewall flexes and overheats, destroying the tire in 20-30 miles.
$15-$25 for a plug-only repair. $25-$40 for a proper inside patch. Patches are the safer fix and last the life of the tire.
The seal between the tire's bead (the inner edge) and the wheel's rim has corroded or shifted. Air escapes around the rim, not through the tread. Fix is to dismount, clean the rim, and remount with bead sealer.
Yes - in fact it's the #3 cause. Rubber stems crack at the base; aluminum stems corrode at the core. A $5 part fixes it.
No, unless they are heavily worn. Replace one tire and rotate to maintain even wear. Some AWD cars need matched tread depth - check your owner's manual.