Desert Heat: Protecting Your Car's Cooling System and Battery

If you live somewhere like Phoenix, Las Vegas or the inland valleys of California and Texas, your car works harder every summer. Extreme heat speeds up wear on batteries, cooling systems, air conditioning, tires and rubber parts. A little preparation helps you avoid getting stranded on a blistering afternoon.

Why heat is hard on cars

High temperatures affect almost every system:

• Engines run hotter and rely heavily on the cooling system.
• Batteries lose fluid and suffer faster internal wear.
• AC systems run nonstop under heavy load.
• Rubber hoses, belts and seals dry out and crack sooner.
• Tire pressure rises and rubber ages faster.
• Fluids break down more quickly.

Many people think cold weather kills batteries, because that is when a weak battery finally fails to start the car. In reality, heat often does the damage that cold weather exposes.

Protect your battery

Heat speeds up the chemical reactions inside a battery and can cause fluid to evaporate, shortening battery life. To get the most from yours:

1. Have it tested before summer and again before winter. Many auto parts stores and shops test batteries for free.
2. Keep terminals clean and tight. Corrosion causes poor connections.
3. Make sure the battery is secure. Vibration can damage internal parts.
4. Park in the shade or a garage when you can.
5. Plan for replacement. Batteries in hot climates tend to need replacing sooner than in mild ones. If yours is several years old, consider replacing it before it fails.

Warning signs include slow cranking, dim headlights at idle, a battery warning light and a swollen or leaking battery case.

Keep the cooling system healthy

The cooling system keeps engine temperature in a safe range. In desert heat, every part of it matters:

• Coolant. Check the level when the engine is cold, and follow the manufacturer's schedule for coolant replacement. Use the type specified in your owner's manual.
• Hoses. Look for cracks, bulges, soft spots or leaks.
• Radiator. Keep the front clear of bugs and debris that block airflow.
• Cooling fans. Make sure they turn on when the engine is hot and the AC is running.
• Water pump and thermostat. Leaks or erratic temperature readings can signal trouble.

Never open a hot radiator cap. Pressurized coolant can cause serious burns.

If your temperature gauge climbs toward hot, turn off the AC and turn on the heater to pull heat away from the engine. Pull over safely and shut off the engine if it keeps rising. Driving an overheated engine can cause expensive damage. Our page on cooling system coverage explains which components plans typically include.

Keep your AC working

In the desert, air conditioning is a safety system, not a luxury. Signs of trouble include warm air from the vents, weak airflow, unusual noises when the AC runs and water or musty smells inside the car.

Help it out by:

• Replacing the cabin air filter on schedule.
• Using a windshield sunshade to reduce cabin heat.
• Venting the car for a minute before turning the AC to maximum.
• Having the system checked if it stops cooling well.

AC compressor and condenser repairs can be costly. See our air conditioning coverage page for how plans handle them.

Do not forget tires and rubber

• Check tire pressure in the morning before driving, when tires are cool. Use the pressure on the driver's door jamb sticker.
• Inspect tires for cracking on the sidewalls, a sign of heat and sun damage.
• Check belts and wiper blades, which dry out faster in the sun.

Pack a summer emergency kit

• Plenty of drinking water.
• A phone charger.
• A sunshade and a light-colored towel.
• Jumper cables or a portable jump starter.
• A small first aid kit.

Many extended warranty plans include roadside assistance, which can be helpful if you break down in extreme heat.

What warranties do and do not cover

Batteries, belts, hoses and tires are often treated as maintenance or wear items and may not be covered by factory or extended warranties. Major components, such as the water pump, radiator or AC compressor, are more commonly covered, depending on the plan.

How Warranty Wizards can help

We help drivers in hot climates compare plans from independent third-party providers and check whether cooling and AC components are covered before buying. You can request a free quote at /get-a-quote/.