The most common cause of a flat tire is a puncture. Sometimes you know what hit your tire, sometimes you don’t. However, sometimes you can search for holes, find one, and yet your tire is still going flat over time.

What can cause this kind of flat tire mystery?

A Faulty Valve Stem

The valve stem is the thing you unscrew to inflate your tire. The valve stem can easily become damaged or corroded. It could also be loose or even simply clogged with dirt. One of the first things to check is that the valve stem is screwing on correctly. Sometimes you can fix this yourself, especially if it’s a clog. However, in most cases, you should go to a mechanic to have the valve stem checked and, if necessary, replaced. New tires generally come with new valve stems, so this is more likely to be a problem if you have not needed new tires in a while.

The Tire is Poorly Seated

This often happens if you pop the curb or rub a wheel against something when parking. You probably won’t notice any damage right away, but will see a mysterious slow leak. A qualified mechanic can easily re-seat your tire, but don’t try to fix this yourself, as you’re likely to make the problem worse.

A Leaky Tire Bead

Along the same lines, sometimes the leak is in the edge of the tire that rests on the rim. These leaks aren’t easily found in a visual inspection. Spraying your wheel and valve system with soapy water can help reveal a leak, which will show up as a stream of small bubbles. Make sure that you do this when the tire is fully inflated. This will save time when you take the car to the shop as you can tell the mechanic where the leak is.

Wheel Corrosion

Sometimes the problem is not your tire, it’s your wheel. The mounting surface of the wheel can become corroded. It can also be dented, which often happens if you hit a pothole or drive down a rough gravel driveway. Alloy rims are also known for being porous, which can be fixed by patching with gasket sealer. This is definitely not something you should attempt yourself. A mechanic will be able to tell you if the wheel can be fixed or if it needs to be replaced.

Overall Tire Wear

Sometimes there is not a specific hole, but rather an area where the tire has worn thin from overall wear. Generally, this means it is time (or past time) for new tires. Uneven tire wear, caused by poor tracking or balance, can make this much more likely.

Temperature Changes

Hot air expands, cold air shrinks. This includes the air inside your tires. This means that hot weather, especially if driving for a while, increases your risk of a blowout. Cold weather can cause the pressure in your tires to drop below safe levels. If there’s a cold snap, you may need to add a bit of air to your tires. In some cases, the low pressure warning will go away after you drive for a few miles and heat up your tires, but you should still check your tire pressure. This is one thing you can probably handle yourself. However, if in doubt, or if you suspect a leak, call a mechanic. Tire problems are more likely to develop in winter when cold rubber is less flexible.

A flat tire can be caused by a variety of factors, not all of which are visible to a simple inspection. Instead, you should check your tire pressure with a gauge about once a month and contact your mechanic if you suspect you have a leak. If you think you may have a leak in one or more tires, contact Anders Automotive to make an appointment today.