What are the reasons for slow tire air leakage but unable to find the leak?

[Zelda]

The following are the reasons for slow tire air leakage but unable to find the leak: 1. Foreign objects puncturing the tire: This is the most common situation. Objects that easily puncture the tire include nails, screws, wires, glass fragments, sharp stones, and tiles. Among these, nails and screws are the most likely to puncture the tire, causing a slow leak. If the tire is punctured by a foreign object, careful observation of the tire surface can reveal it. If the puncture location is hidden, you can sprinkle water on the tire surface to find bubbles or hear a "hissing" sound of air escaping. 2. Leaky valve core: If you pour water on the valve core and see bubbles, it indicates a leaky valve core. In this case, simply loosen the dust cap a bit, as being too tight can press against the valve core and cause air leakage. 3. Damage to the tire sidewall: Besides the tire tread being easily punctured by foreign objects, the sidewall and inner edge of the tire can also be damaged. Some drivers have poor spatial awareness and often scrape the tire sidewall against the curb when parking. Once or twice may not cause issues, but repeated occurrences can wear down the tire sidewall.