A CAR expert has revealed three signs your car is suffering from a slow puncture and a £2 Amazon gadget that can fix it in seconds.
The tiny tool could make all the difference if you get caught on the roadside and save you shelling out hundreds for a tow truck.
Dave Alexander from Auto Garage Life shared the handy hack on his YouTube channel.
Demonstrating on his gorgeous Ford Mustang, Dave urged drivers to get hold of a valve tool for peace of mind even when their tyres are feeling low.
Dave said: "This little tyre tool is actually four tools in one.
"I've had one of these in my toolbox for 20-odd years and I use it relatively often.
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"If you are constantly putting air in your tyre then you might have a slow puncture coming from somewhere.
"You'd probably do well to check the valve...[unless] there are any obvious nails or screws in it, this is the other obvious place to check for a puncture."
He explained that a slow puncture, where tyre pressure declines very gradually over time, can be caused by the valve on the tyre itself being a little loose.
This can happen naturally through wear and tear but allows small amounts of air to escape as you drive along.
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Fortunately, you can use one of the four ends of the valve tool to correct this.
The device has one arm which features a notch in the metal end.
This can be inserted into the valve and gently used to tighten it back up by turning to the left.
Don't do this too hard as overtightening can lead to a more severe puncture.
The tool also has three other attachments, which can be use to clean both the inside and outside of the valve and keep it in good condition.
Valve tools are available online for as little as £2 from Amazon.
That could save you big, though, as roadside recovery if you break down can run into the hundreds.
It comes after we revealed a free check drivers can do to stop their cars overheating in today's 31C temperatures.