If your car has a tire that’s losing 10 PSI overnight, then this article is just for you.
Tire leaks are very common and losing 10 PSI overnight indicates a pretty decent size leak, which should be quite easy to find.
Luckily, there are only a handful of ways that a tire can lose a decent chunk of pressure in a short timeframe, thus finding the leak and fixing it comes down to knowing the tire’s weak points and giving them a quick check.
With that said, let’s go straight to the point and get you back on the road.
Four Possible Reasons Why a Tire Loses 10 PSI Overnight
While it’s normal for car tires to slowly lose pressure at the rate of 1-3 PSI a month, a 10 PSI decrease overnight indicates a pretty substantial leak, which most is most often caused by a puncture in the tread.
However, each case is different and your tire might be leaking for a whole different reason.
Here are all the possible ways that a tire can develop a leak, the most likely ones are at the top.
1. Puncture in the Tread or Sidewall
The most common cause of a 10 PSI overnight tire leak are punctures in the tread area, which is always in contact with the road.
There are lots of junk on the roads, including sharp objects like nails and screws, thus it’s only a matter of time before your tires will get pierced by them. Luckily, the object that caused the puncture will often remain lodged in the tire and prevent air from escaping quickly.
Punctures with sharp objects can leak at a rate of 1-3 PSI a day, or even 10 PSI and more.
2. Bent or Damaged Wheel
Potholes are nasty. Not only do they rattle the hell out of your car’s suspension, but they can also damage your wheel and cause a substantial tire leak.
If you’ve recently hit a big pothole, then your tire leak might be caused by the impact bending your wheel and preventing the tire to seal properly against it. In that case, your tire will leak around the area where it makes contact with the wheel.
With that said, corrosion at the bead seat area can also cause a tire leak, although in that case, the tire will leak lower than 10 PSI overnight.
3. Leaky Valve Stem
Another common reason for tire leaks are bad valve stems. They’re made from rubber, which does degrade over time due to exposure to the elements.
Valve stems can leak from the inner valve itself, the valve’s rubber body, or the area where the valve stem seals to the wheel.
These bad boys usually leak at a very slow rate of 1-3 PSI per day if they go bad, but if the leak is at the valve core, then a bad valve stem can easily let the tire leak 10 PSI overnight.
4. Dry Rot
Dry rot is just a term for really old, cracked, and brittle tires. As the name suggests, the rubber compounds of the tire dry out and decay over time.
If your tire has small hairline cracks on the sidewall or the tread like in the picture above, then your tire has dry rot. In some cases, these small cracks can leak and easily cause your tire to lose 10 PSI overnight.
5. Bead Damage
If the leak appeared after replacing tires, it could be due to bead damage.
The tire’s bead is the area that contacts and seals against the wheel. In some cases, inexperienced technicians might accidentally damage the tire’s bead while mounting the tire onto the wheel.
Furthermore, bead damage can occur over time if the tire is very old or if something gets lodged between the bead and the beat seat of the wheel.
Bead damage usually leaks at a slow rate but can reach 10 PSI overnight in some cases.
How to Find a Tire Leak
Since your tire is losing 10 PSI overnight, then locating the leak shouldn’t be difficult. There are three ways that you can reliably find tire leaks.
Sound & Feel
If you’re lucky enough to have sensitive hearing, then you can use sound to locate tire leaks.
Try to remove the wheel if possible, put your ear close to the tire and listen for a hissing sound. You can also run your hand around the tire and feel for air escaping.
Probably the best way to find tire leaks is by using soapy water or leak detector spray. They’re both made from 70% water and 30% dish soap.
Remove the wheel if possible and spray soapy water all around the area where the tire touches the wheel to check for bent wheel or bead damage.
Next, spray soapy water all around the tread and the sidewall to check for punctures.
Lastly, spray soapy water on the valve stem. You can also remove the valve stem dust cap and spray soapy water inside to check if the valve core is leaking. Also, don’t forget to spray on the base of the valve stem cap where it touches the wheel.
If a leak is present, bubbles will start to appear in the leak area. Sometimes it might take a few minutes for bubbles to appear, so be patient and persistent.
Put the Wheel Into Water
Another popular way to find tire leaks is by submerging the tire underwater. Once the tire is underwater, any leaking air will escape as bubbles, thus revealing the area of the leak. You may need to keep the tire submerged for a few minutes to see bubbles.
How to Fix a Tire That’s Loosing 10 PSI Overnight
Now that you know where to look for tire leaks and how to find them, it’s time to find out how to fix them and get back on the road.
Use a Plug Kit for Punctures
Punctures in the tread area are the most common reason for tire leaks and luckily the easiest to fix. The best way to fix punctures is with a plug kit. A plug kit consists of a set of rubber plugs, rubber cement, a plug tool, and the reaming tool.
If plugged correctly, the tire is safe to use and the plug should hold air for the lifetime of the tire. Here’s how you do it:
- Remove the wheel if you can – it will be easier to work that way.
- Remove the nail from the tire and use the reaming tool to clean the hole. Don’t go crazy with the reaming tool, just a couple of passes to clean and prep the hole in the tire.
- Insert the plug into the plug tool and cover it well with rubber cement.
- Insert the plug into the hole using the plug tool.
- Quickly pull the plug tool out.
- Cut off the remains of the plug with a knife, scissors, or pliers.
- Let the plug dry out for a few minutes
- Pump the tire back up and drive home.
This is the process for punctures in the tread, but if the puncture is in the sidewall, then the tire is trashed. You cannot safely plug a sidewall puncture.
Replace The Valve Stem
If the valve stem is the culprit behind your tire losing 10 PSI overnight, then the only way to fix it is by replacing the valve stem or its core.
If it’s only the core (found under the dust cap) that’s leaking and not the rubber body of the valve stem itself, then you can unscrew it and replace it with a new core for less than 50 cents.
However, if the valve stem is leaking around the base and sealing improperly against the rim, then you will have to replace the whole valve stem. This requires removing the tire from the wheel, thus it’s best to be done at a tire shop.
Repair The Rim
Bent wheels are the worst. Not only is it very difficult to straighten out and repair a bent wheel by yourself, but paying a tire shop to do it is pretty expensive as well.
Getting your wheel repaired by a professional is definitely the best choice that you can make. Aluminum can be pretty brittle and if you don’t know what you’re doing, you can easily break the wheel and make it unsalvagable.
Dry Rot or Bead Damage?
If your tire is losing 10 PSI overnight due to dry rot or bead damage, then it’s time to buy a new tire. There is no proper way to reliably and safely fix dry rot and bead damage.
Tire leaks are no fun and they can quickly ruin your day. However, there are only a handful of spots where leaks could occur on a tire. As long as you know where these spots are, finding tire leaks won’t take you much time at all.
Some leaks are not worth fixing, such as dry rot, bead damage, and sidewall punctures. In that case, you will be better off buying a new tire.
Eddie is the co-founder of CarCareCamp.com, and the site’s primary contributor.
Under his belt, Eddie has a bachelor’s degree in Automotive Electronics Engineering and almost a decade of experience working as a semi-truck technician (specializing in electrics).