Why Is My Tire Losing Air Overnight, How Can I Fix It?

A common vehicle maintenance concern among drivers is the slow loss of air from tires, often noticeable when it appears flatter after sitting overnight. The question comes, why is my tire losing air overnight? Several reasons can be responsible for this seemingly mysterious loss of pressure Understanding them can help motorists address the problem and ensure a safer drive. Is losing air a simple fix or a symptom of a bigger issue? Here, we’ll explore the reasons behind brand new tire flat overnight and the corresponding remedies.

tire losing pressure but no leak

Why Is My Tire Losing Air Overnight?

Here are the primary reasons why a tire might lose air overnight:

1. Punctures

One of the most common reasons is a small puncture or leak caused by a nail, screw, or bolt embedded in tire. These punctures might be so tiny that they only cause a slow leak, which becomes evident after the vehicle sits overnight.

2. Faulty Valve Stems:

The valve stem is the tiny protrusion from your tire that you unscrew when you need to inflate it. Over time, these can become damaged, corroded, or loose, allowing air to escape.

3. Bead Leaks

The bead of a tire refers to the edge of it that sits on the wheel. If there’s damage, corrosion, or dirt between the bead and the rim, it can create a path for air to escape, causing the tire to deflate slowly.

4. Damaged Wheels or Rims

Dents, cracks, or rust on your wheel or rim can provide an avenue for pressure loss. Even minor damages can cause the tire not to seal correctly, leading to a slow leak.

5. Temperature Fluctuations

The principle behind this is the ideal gas law, which states that the pressure and volume of a gas change in proportion to its temperature. Cold weather can cause the air to contract, reducing its volume and thus, its pressure. While this doesn’t mean your tire is lacking pressure, it can appear so, especially if the temperature drop is significant.

6. Wheel Weights

Wheel weights are sometimes installed on the inner side of the wheel to balance tires. If incorrectly positioned, they might damage the inner liner and make tire losing pressure but no leak.

7. Aging Tires

As tires age, their rubber loses elasticity and becomes porous. Over time, this can lead to minute leaks, especially if those are frequently exposed to harsh conditions.

8. Previous Repairs

A poorly executed puncture repair or tire plug might not seal entirely, allowing air to escape slowly.

Can Tires Lose Air Without a Leak?

Yes, tires can lose air without a noticeable puncture or leak. One primary reason is permeation, a natural process where gas molecules escape through the rubber compound. Even without damage, tires can typically lose one to two pounds per square inch (PSI) per month due to permeation alone. Additionally, temperature fluctuations play a significant role. As temperatures drop, the air contracts, reducing pressure. For every 10°F change in ambient temperature, the pressure can alter by about 1 PSI.

Other factors as mentioned above are also liable for contributing to this phenomenon, including changes in altitude and minor imperfections in the valve stem or bead seating. The rubber may become more porous as aged, especially if exposed to harsh conditions, resulting in increased air loss. Furthermore, previous repairs or the constant flexing and compression tires undergo while driving can also lead to minor gas escape. Regularly monitoring the pressure ensures safety and optimal vehicle performance.

How Do You Find an Air Leak in a Tire?

Finding a leak in a tire can sometimes be challenging, especially if the leak is small or intermittent. Here’s a step-by-step guide to help you locate the source of the leak:

Visual Inspection:

Begin by doing a thorough visual inspection of the tire.

Look for obvious signs like nails, screws, shards of glass, or any other foreign objects embedded in the tread.

Examine the sidewalls for cuts, cracks, or bulges.

Listen Carefully:

In a quiet environment, move your ear close to the tire and listen for a hissing sound. Sometimes, you can hear the air escaping from a small puncture.

The Soapy Water Test:

This is one of the most effective methods to find a leak.

Mix a soapy water solution (dish soap works well) in a spray bottle or a bucket.

Spray or brush the soapy solution generously over the tire, including the tread, sidewalls, and valve stem.

Watch for bubbles to form. The escaping air will create bubbles in the soapy water, indicating the location of the leak.

Focus on areas around the valve stem, as these can often be sources of slow leaks if the stem is damaged or the valve core is not seated correctly.

Check the Bead:

The bead is where the tire seals against the rim. Corrosion or debris can compromise this seal, leading to a leak.

Use the soapy water test around the rim edge to detect any leaks in this area.

Submersion Test:

checking tire air leaks

If the soapy water test doesn’t reveal the leak or if you want to confirm a suspected leak:

Fill a large tub or container with water.

Submerge one section of the tire at a time into the water.

Look for streams of bubbles coming from it. These bubbles will show you exactly where the tire is leaking.

Inspect the Valve:

Sometimes, the valve stem or valve core can be the culprit.

Apply soapy water around the base of the valve stem and the valve core itself. If bubbles form, you’ve found a potential leak source.

If the valve core is the issue, it can often be tightened or replaced to resolve the leak.

Seek Professional Help:

If you’ve tried the above methods and still can’t locate the leak or are unsure about the severity of a found issue, it’s best to consult a specialist or auto mechanic. They have specialized equipment and expertise to identify and fix tire leaks.

Once you’ve located the leak, it’s essential to repair it properly. Small punctures in the tread area can often be repaired using a patch/plug combination. However, punctures in the sidewall or damaged tires must be replaced for safety reasons.

How Long Does It Take for a Slow Leak to Flatten a Tire?

The time it takes for a slow leak to flatten a tire varies greatly depending on the size of the leak, the initial tire pressure, and the volume. Here is a breakdown:

  1. Very Slow Leaks: These are leaks that might cause the tire to lose 1-3 psi (pounds per square inch) over the course of a week. At this rate, if you start with a pressure of 30 psi, it would take several weeks to months to become significantly underinflated.
  2. Slow Leaks: If the tire is losing about 1-2 psi per day, you’d notice a significant drop in pressure within a week.
  3. Moderate Leaks: Leaks causing a loss of 2-5 psi per day would make it noticeably flat in a matter of days.
  4. Fast Leaks: If you’re trailing more than 5 psi per day, it will be flat within a day or two.

Remember, driving on an underinflated tire can cause damage, reduce fuel efficiency, and compromise the safety of the vehicle due to reduced handling and braking capabilities.

How Do You Fix a Tire That Keeps Losing Air?

If your wheel consistently loses air, it’s essential to pinpoint the problem and address it appropriately. Here’s a systematic approach to fixing a tire went flat overnight but now holds air:

1. Identify the Source of the Leak:

  • Start with a visual inspection for nails, screws, or other foreign objects.
  • Use the soapy water method: Spray the tire with soapy water and watch for bubbles indicating a leak.
  • Pay special attention to the valve stem and where the bead meets the rim.

2. Puncture Repair:

  • If the leak is due to a puncture in the tread area, you can use a plug or patch/plug combination to seal it.
  • Clean the area around the hole and follow the repair kit instructions.
  • Remember that punctures in the sidewall should not be repaired; the tire will need to be replaced.

3. Valve Stem and Core:

Fixing Tire Valve YouTube
  • If the valve stem is the culprit, it might need to be replaced. This job can be done relatively quickly by a professional.
  • A faulty valve core can be removed and replaced using a valve core tool.

4. Bead Seal:

  • If the leak is at the bead (where the tire meets the rim), it may require reseating or cleaning the rim. Corrosion or debris on the edge can prevent a proper seal.
  • Sometimes, a bead sealer can be applied to ensure an airtight bond.

5. Check the Rim:

  • Dents, cracks, or corrosion in the wheel or rim can lead to air loss. Such issues might require the rim to be repaired or replaced.

6. Replace the Tire:

tire replacing
  • If the tire is old, has significant wear, or has damage that cannot be repaired (like sidewall punctures or large gashes), it is safer to replace it.

7. Regular Maintenance:

  • Always maintain your tires at the recommended pressure.
  • Regularly inspect them for signs of wear, damage, or embedded objects.

8. Consult a Professional:

  • If you need clarification on the source of the leak or the appropriate repair method, consult a vehicle mechanic. They can offer expert advice and ensure the repair is done correctly.

Regular inspections and proper maintenance are vital to extending the life of your tires and ensuring a safe driving experience. If you notice consistent pressure loss, address the issue promptly to avoid more significant problems or potential hazards on the road.

How to Keep Tires from Losing Air?

To minimize the chances of trailing air and to ensure they remain at the recommended pressure for extended periods, follow these preventive and maintenance tips:

  1. Regularly Check Tire Pressure:
    • At least once a month, use a quality pressure gauge to check tire pressures and put air in tires as required.
    • Always check the pressure when cold, preferably in the morning, as driving heats the wheel and may result in inaccurate readings.
  2. Inspect Tires for Damage:
    • Routinely inspect tires for any signs of punctures, like nails or screws, and other damages, such as cuts, cracks, or bulges.
    • Remove any debris from the treads which might lead to a puncture over time.
  3. Ensure a Good Bead Seal:
    • Clean the rims periodically. Dirt and corrosion can interfere with the bead seal on the edge.
    • If changing a tire, ensure it is appropriately seated on the rim.
  4. Regularly Check Valve Stems and Caps:
    • A damaged or deteriorated valve stem can cause slow leaks. Ensure valve stems are in good condition and replace them if necessary.
    • Always ensure that the valve caps are securely in place. They remove dirt and debris and offer an additional seal against slow leaks.
  5. Use Nitrogen:
    • Filling tires with nitrogen can maintain the pressure for longer since nitrogen molecules are larger than oxygen molecules and are less likely to permeate the walls. However, the benefits are debated, and regular air is primarily composed of nitrogen (~78%).
  6. Avoid Potholes and Other Road Hazards:
    • Impact with potholes or sharp objects can cause immediate punctures and weaken the tire or cause minor damages that lead to slow leaks over time.
  7. Maintain Proper Wheel Alignment:
    • Misaligned wheels can cause uneven tire wear leading to areas becoming more susceptible to leaks.
  8. Rotate Tires Regularly:
    • Rotating tires every 6,000 to 8,000 miles can help in even wear and reduce damage due to prolonged stress.
  9. Avoid Overloading Your Vehicle:
    • Excessive weight stresses the tires, increasing the chances of damage and air loss. Always adhere to your vehicle’s weight limit specifications.
  10. Replace Old or Damaged Tires:
  • If a tire consistently loses air, even after attempts to repair it, or if it’s old and showing signs of wear, it might be time to replace it.

By proactively taking care of your tires and attending to any issues promptly, you can substantially reduce the chances of them losing air. Regular maintenance ensures the safety, optimal performance, and longevity of the parts.

To Sum Up

A tire that loses air overnight can be a nuisance and a potential safety hazard. It’s essential to identify the source of the leak and address it promptly. Regular inspections and maintenance can keep such issues like tire losing air but no hole at bay and ensure a safer driving experience.


Mr. Shafiqule Islam is a graduated Mechanical Engineer and has more than 15 years experience of repairing and maintenance of different brand vehicles like Toyota, Mitsubishi, Ford, Mercedes, BMW etc. He is also giving training to Mechanics. He has started writing to share his practical knowledge to Vehicle Owners, Drivers and Mechanics to keep their cars at best fit.

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