Blog Car Care Advice Common Car Issues Due to Excessive Heat
Car Care Advice

Common Car Issues Due to Excessive Heat

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No matter where you live in the States, summer is arguably one of the best seasons to hit the great outdoors. As the days have heated up, some people prefer relaxing on the beach, while others enjoy hiking and camping. One thing many people have in common this summer is relying on their cars more than ever to enjoy what’s left of summer.

Summer can be a tough time for your vehicle as it is frequently operating outside its normal temperature range. And this can cause a host of problems if your car is not properly prepared for the heat. To ensure your summer is one to remember, we’ve outlined the most common issues caused by excessive heat and how to prevent them.

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Along with overcharging, hot weather is a leading cause of shortened battery life. On a hot day, a battery can reach internal temperatures above 140 degrees, far above the ideal operating temperature of 80 degrees. Every 15 degrees Fahrenheit the ambient temperature increases cuts the battery’s life cycle by nearly half.

Along with overcharging, hot weather is a leading cause of shortened battery life.

Hot weather can cause the liquid electrolyte solution that is inside the battery to evaporate. This can expose the lead plates and cause internal corrosion, limiting the batteries ability to hold a charge and a decreased ability to produce enough power to start an engine. Increased power demands from air conditioning and vehicle cooling systems also puts a constant drain on the battery.


As the temperature soars, the road becomes hotter, and checking your tire pressure becomes more important. Tire pressure increases approximately one pound per square inch (psi) with every 10 degrees Fahrenheit increase in temperature.

Tire pressure increases approximately one pound per square inch (psi) with every 10 degrees Fahrenheit increase in temperature.

The excessive heat and subsequent increase in tire pressure can cause the tires to become overinflated. This excess air pressure can deform the shape of the tire, decreasing the amount of tread that is in contact with the road. It will also cause excessive wear along the center of the tire, and in extreme temperatures, it is possible that the rubber can disintegrate.


Extreme heat ages engine oil, causing it to thicken and decrease in viscosity (how easily the oil flows). As the lighter parts of the oil evaporate and gas is released, molecules in the oil lose stability, becoming hyperactive. As the oil degrades it allowing sludge, resin, and varnish deposits to form in greater amounts. This also leaves the engine more susceptible to abrasion, scuffing, and corrosion.

Other consequences of extremely high oil temperature also include:

Cooling System

Several parts including your water pump, thermostat, radiator, hoses, and coolant make up your vehicle’s cooling system. Working in extreme heat can cause additional stress on the cooling system, and when a part fails, the engine temperature rises, putting the engine at risk of serious damage.

When one part of the cooling system stops working, the entire cooling system fails. If your cooling system is not up to scratch, to begin with, driving in heavy traffic with little airflow to the radiator can accelerate its demise.


Fuel economy can worsen in hot weather due to the excessive heat causing pre-detonation of the air/fuel mixture. As the air becomes hotter, its molecules gain energy, causing them to move faster. As their speed increases, so does the distance between them, making the hot air going into your motor less dense.

This can cause pre-detonation – when the air/fuel mixture ignites prematurely before the spark plug ignites it. When this happens you will be able to hear a slight ‘pinging’ or ‘knocking’ sound from your engine. This can damage the spark plugs and in extreme cases, or if not fixed, can even damage pistons and break piston rings.

Checklist Before Driving In Hot Weather

Assess Your Battery’s Health

A car battery will usually last between three to five years under normal conditions. You can easily check the health of your battery with a multimeter. If you don’t have one, ask your mechanic to check it for you.

As an alternative, you can perform a simple load test yourself by performing the following steps:

If your car struggles to start, or if the lights dim when you attempt to start the car, your battery is on the way out and should be replaced.

You should also give the battery and battery terminals a quick visual check to see if there is any buildup or corrosion. If there is a buildup present, it can be carefully cleaned off, but be aware that you are dealing with a caustic material. So, if you’re doing it yourself, be sure to take the necessary precautions such as gloves and safety glasses.

Check The Fluids

Your vehicle’s fluids do a lot of heavy lifting in hot weather, by making sure your engine is lubricated and kept cool. All that’s needed is a visual check to make sure they’re not low. The fluids you’ll want to keep an eye on, are your engine oil, coolant, power steering, transmission, and brake fluid. The location of each reservoir varies between different cars, but your owner’s manual will provide a picture of where they are and explain how to check them on your particular vehicle. If they need to be topped up, be sure to use the fluid recommended in the owners manual, or ask your mechanic what they recommend for your vehicle.

Prepare Your Air Conditioner

Nothing can turn a comfortable road trip into a brutal desert crossing quicker than a failed air conditioner system.

You’ll also want to take note of any odd smells as this indicates the presence of bacteria. Your air conditioner uses an air filter similar to the one on your engine, and this should be replaced about every 12,000 – 15,000 miles to keep dust and debris out of the air that’s circulating around your car. If your car fails any of the above tests, or the air conditioner isn’t as cold as it should be, your mechanic will need to perform a diagnostic test to pinpoint the problem.

Check Your Tires

We’ve covered how to check your tires in a previous article titled ‘Everything You Need To Know About Tires’. The two main things to keep an eye on are the air pressure and making sure your tires are wearing evenly. Because the heat will cause the air in your tires to expand, it’s a good idea to get into the habit of checking your tire pressure once every two weeks. The recommended tire pressure for your vehicle can be found on a sticker or placard around the driver’s door. You may also want to invest in a cheap hand-held tire gauge if you don’t already have one. Driving on overinflated or under-inflated tires doesn’t just cause premature wear, it can increase your braking distance and affect steering response and how your vehicle handles. Also check your spare tire, or your repair kit to see if anything is missing.

Inspect The Belts And Hoses

A hot engine coupled with hot weather can cause belts and hoses to lose their flexibility, crack, or fail completely. This can be easily inspected while the engine is switched off. Look for any cracks, fraying, nicks, or bulges. Squeeze the radiator hose which should feel firm, but pliant. Any hose or belt that is showing signs of wear needs to be replaced as soon as possible.

A hot engine coupled with hot weather can cause belts and hoses to lose their flexibility, crack, or fail completely.

Tips For Driving In Hot Weather

Be Prepared

If you’re expecting a spell of extreme heat or traveling a long distance, keep a well-stocked emergency kit in your vehicle. This should include some first aid supplies, water, snacks, a flashlight, sunscreen, some basic tools, and jumper cables.

Get Comfortable

Hot weather can bring out the worst in people, especially on the road, so make sure you’re comfortable before you set off. Clean your windshield if necessary, check that your phone is fully charged, make sure you have some music to relax you, and know where the rest areas and gas stations are located if you need to pull over during your journey.

Plan Ahead

If your car does break down, following a plan that you’ve already prepared can make managing a stressful situation easy. Store the number for a mobile mechanic and local towing service in your phone, and learn how to perform some basic jobs like jump-starting a car and changing a tire so you can get moving again fast.

Keep Hydrated

We often don’t recognize that we’re overheating until after it’s happened. An insulated drink bottle that has been pre-chilled is a great way to ensure you have enough cold water at hand.

Expect The Unexpected

The longer daylight hours of summer mean animals are active for longer. But the warm weather can also mean additional cars on the road, more people exercising, heavy machinery getting moved and more people cycling to work. Be extra vigilant and avoid taking risks.