Slow punctures are common but understandably more challenging to detect compared to a sudden puncture. In this article, we cover how to identify if you have a slow puncture, what causes it and how to repair a slow puncture.
What is a slow puncture?
Slow punctures are tiny, almost undetectable holes in a vehicle’s tyre that slowly let the air inside escape. Compared to sudden punctures or tyre blowouts, slow punctures don’t require you to stop the car or slow down immediately. Instead, with a slow puncture, the tyres will deflate gradually, taking several days or even weeks before you notice that it has deflated.
Many drivers mistake this for low tyre pressure and resort to inflating it instead of repairing it. This will help with a temporary fix but if it’s indeed a slow puncture, it will eventually deflate again.
What causes a slow puncture?
Some common causes of a slow puncture include:
A slow puncture can occur when hitting a particularly nasty pothole or kerb, which damages the wheel rim or sidewall inside the tyre.
The most common cause of slow punctures is driving over something sharp such as a nail, screws, or loose pieces of debris in the road.
If the (steel) wheel becomes rusty, then it might cause gaps that can lead to a slow puncture. In the case of alloy wheels, the metal can become porous over time allowing the air to seep through the metal.
Although uncommon, other issues that cause a slow puncture include faulty valve stems, cracked tyres, corrosion on the bead or even just sub-standard tyres.
Symptoms of a slow puncture
Slow punctures are certainly harder to identify than a sudden puncture but there are some tell-tale signs that you should look out for:
Refilling air pressure more often:
If you find yourself stopping at the petrol station more often than usual to inflate the tyre air pressure to the recommended limit, make a note of which tyre has the lowest PSI reading. It’s worth getting this checked by a mechanic to ensure it’s not suffering from a slow tyre puncture.
Car drifting to one side
This one is not super obvious but if you suspect that you may have a slow puncture, then you can double-check by driving along a straight, quiet road and briefly loosening your grip on the steering wheel. Be wary of your surroundings when doing this test!
If you find that the car is drifting on one side, it could be an indication that something is wrong with the tyres. This could also be a symptom of bad wheel alignment. Either way, it’s best to get it checked by a mechanic.
A vibrating steering wheel:
Slow punctures will result in the tyre having reduced air pressure which will result in unbalanced tyres. This may in turn cause the steering wheel to vibrate especially at higher speeds on the motorway.
How to repair a slow puncture
Whether a slow puncture can be repaired often depends on what is causing the puncture and the extent of the damage. For example, if it’s a piece of nail that is embedded in the tyre, then a mechanic may be able to insert a rubber plug and repair the puncture hole.
Sometimes, it could be a leaking valve which is letting the air escape. You can do a quick test yourself to check if you need a valve replacement by rubbing some soapy water around the valve after inflating the tyre and checking to see if any bubbles form – indicating that the air is escaping.
If the slow puncture is due to damage to the tyre’s sidewall, then it is quite likely that the tyre will need a replacement.
You should check your car’s tyres regularly – at least once a month – to ensure they are in good condition. Remember, tyres are the only thing keeping your vehicle in contact with the road so it’s critical that they are in good shape! A tyre pressure gauge and tread checker is a handy tool to own which enables you to check tyre pressure and tread depth quickly and accurately.
You should not ignore a slow puncture, as a partially inflated tyre can affect your car’s braking and handling performance. When you drive on a tyre with a slow puncture, you can further damage the tyre, which means you’ll have to replace it rather than repair it. It’s safer and much more cost-effective to attend to a slow puncture sooner rather than later.
If you need a tyre fitting, you can get an instant price by entering your registration number and postcode on our website.