Tires & wheels

Tire keeps losing air slowly

A tire that needs air every week or two almost always has a small puncture, a leaky valve, or a bad seal at the wheel rim. It can usually be found and fixed cheaply.

Difficulty
Easy
Time
15–30 minutes to diagnose
DIY cost
$0–$15
Pro cost
$20–$45

Symptoms

  • Low tire pressure warning returns every 1–3 weeks
  • One tire is always lower than the others
  • Tire looks fine but keeps needing air
  • No obvious flat, just gradual loss

Likely causes

  • CommonSmall nail or screw punctureA slow leak often means the object is still lodged in the tread, sealing part of the hole.
  • CommonLeaking valve stem or valve coreRubber valve stems dry out and crack over time, leaking air slowly.
  • PossibleCorroded or dirty wheel bead sealRust or road grime between the tire and rim can let air seep out.
  • Less commonCracked wheel rimA hairline crack from curb impact can leak air slowly.

What to do

  1. Check tire pressure with a gauge and compare all four tires to the recommended PSI on the driver door jamb sticker.
  2. Inspect the tread visually for anything embedded, like a nail or screw.
  3. Spray a mix of water and dish soap on the tread, sidewall, and valve stem and watch for bubbles.
  4. If you find a puncture in the tread, note its location for repair.
  5. Check the valve stem itself for cracking or a hissing sound at the tip.
  6. Add air to the correct pressure as a temporary measure if you must drive.
  7. Take the wheel to a tire shop for a proper patch or valve replacement rather than relying on refills.

Tools and parts

  • Tire pressure gauge
  • Spray bottle with soapy water
  • Air compressor or access to a gas station air pump
Replacement valve stem or valve coreSearch: “tire valve stem replacement”
Tire plug patch kitSearch: “tire plug patch kit”

When to call a pro

If the leak is on the sidewall rather than the tread, or you can't find the source, have a tire shop inspect and repair it rather than continuing to add air.

Safety

Generally low risk

Generally low risk for a careful person. Stop if anything looks different from what this guide describes.

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.