Keeping your car running smoothly can sometimes feel like a constant battle. From strange noises to dashboard warning lights, it's easy to feel overwhelmed when something goes wrong. But once you understand the most common car problems, you can take proactive steps that save you time, money and stress down the road.

Common car problems can range from simple fixes you can handle yourself to more complex repairs that require a professional. Below, we'll walk through some of the most common culprits and explain the symptoms, possible causes and estimated repair costs you should know.

1. The Check Engine Light Is On

You've most likely seen your check engine light illuminated on your dashboard before, but its status can tell you a lot about what car problems you're experiencing. This small but significant indicator is part of your car's onboard diagnostic system, designed to alert you to potential problems with various engine components, emissions systems and other critical functions. It's one of the more common car issues drivers face.

A steady check engine light usually indicates a problem that needs attention but not immediate roadside assistance. It could be anything from a loose gas cap (a surprisingly frequent cause) to a malfunctioning oxygen sensor. Alternatively, a flashing check engine light is more serious, indicating a problem that could cause immediate damage to the catalytic converter or other vital engine parts. If your check engine light is flashing, avoid driving the vehicle further.

2. The Engine is Overheating

An overheating engine is a serious problem that should be addressed promptly. Common signs include:

• There is steam or a burning smell coming from under the hood.
• The temperature gauge on your dashboard moves into the "red" or "H" zone.
• You notice a loss of engine power.
• Coolant leaks onto the ground.

If you notice any of these symptoms, pull over to a safe location as soon as possible and turn off the engine. Several factors can contribute to a car engine overheating, including:

• Low coolant levels due to leaks in the cooling system (hoses, radiator, water pump)
• A malfunctioning thermostat (which regulates coolant flow)
• A faulty water pump (which circulates coolant)
• A clogged radiator

3. Fluid Leaks Under the Car

Finding a puddle under your parked car can be a concerning car problem to have. Different fluids have distinct characteristics that can help you pinpoint the source. Here are some common ones:

• Oil leaks: Typically dark brown or black, greasy and have a distinct odor.
• Transmission fluid is typically reddish-brown (though it can darken with age), has a sweet smell and feels oily.
• Coolant can be green, orange, pink or blue and has a sweet smell.
• Brake fluid is light yellow to clear and has a distinct, almost fishy smell.
• Power steering fluid is usually clear to amber and slightly oily.

A leak near the front of the car might indicate a coolant leak from the radiator or hoses, while a leak near the middle could suggest a transmission or oil leak.

Fluid leaks can stem from various causes, such as worn seals, damaged hoses or cracks in fluid reservoirs. Here are the typical causes of different fluids:

• Oil leaks: Worn valve cover gaskets, oil pan gaskets or damaged oil lines can create oil leaks. Ignoring oil leaks can lead to engine damage due to insufficient lubrication.
• Transmission fluid: Worn seals or damaged transmission pan gaskets cause transmission fluid leaks. Low transmission fluid levels due to leaks can cause transmission slipping, overheating and eventual failure.
• Coolant: Cracked hoses, a leaking radiator or a faulty water pump can cause coolant to leak. Ignoring coolant leaks can lead to engine overheating, which could lead to a cracked engine block or blown head gasket.
• Brake fluid: Brake fluid leaks are more serious and often indicate a problem with the brake lines, calipers, or wheel cylinders. Brake fluid leaks directly compromise braking ability, which poses a safety risk.
• Power steering fluid: Worn hoses or a leaking power steering pump will often cause power steering fluid leaks. Low power steering fluid can make steering difficult, especially at low speeds, and can eventually damage the power steering pump.

4. Transmission Slipping

Transmission slipping is a serious problem that affects your car's ability to shift gears correctly. It feels like the engine is revving higher than it should for the current speed. Another symptom is if the car momentarily loses power or "slips" out of gear. This can manifest as any of the following:

• A delay in acceleration when you press the gas pedal
• A sudden surge or lurching sensation during shifting
• Difficulty maintaining a consistent speed, especially when going uphill

You might also notice noises like whining or grinding or a burning smell coming from the transmission.

Your transmission can slip due to low or contaminated transmission fluid (which lubricates and cools the transmission), worn-out clutches or bands inside the transmission, internal mechanical problems within the transmission itself or a faulty torque converter (in automatic transmissions).

5. Braking Issues

There are several things to look out for that indicate an issue with your braking system:

• Squeaking or squealing noises when you apply the brakes: This is often a sign of worn brake pads, a common issue that is usually relatively inexpensive to fix.
• Pulsating or vibrating feeling in the brake pedal or steering wheel when braking: This can indicate warped brake rotors. This car malfunction requires resurfacing or replacing the rotors.
• A spongy or soft brake pedal: A spongy or soft brake pedal occurs when the car travels further than usual before engaging the brakes. This could indicate air in the brake lines or a leak in the hydraulic system.
• Pulling to one side when braking: This may indicate a problem with a brake caliper or uneven brake wear.
• Burning smell: This could indicate overheated brakes, which can reduce their effectiveness.

6. The Car Won't Start

A car may refuse to start for a variety of reasons:

• Dead battery: If you turn the key and hear a rapid clicking sound, it likely means the battery doesn't have enough charge.
• Faulty starter motor: The starter motor might be the issue if you turn the key and hear a single click or nothing at all, even with a charged battery.
• Alternator issue: If the engine cranks slowly, it could be a problem with the alternator. The alternator is the prime suspect if the car starts with a jump start but dies shortly after.

Other less common causes of a no-start condition include a faulty ignition switch, a problem with the wiring or a lack of fuel.

7. Tires Are Wearing Unevenly

Uneven tire wear shortens tire lifespan, and regularly checking the tread is key. The quarter test helps: insert a quarter upside down into the tread. If Washington's head is fully visible, your tread is below 4/32 of an inch and it's time to begin looking for tires.

Beyond basic wear, worn tire patterns reveal issues. Outer edge wear suggests underinflation, center wear indicates overinflation and one-sided wear points to misalignment.

Check your pressure monthly (and before long trips) with a gauge and inflate tires to the pressure listed in your owner's manual. Regular tire rotations (every 5,000-7,000 miles) also distribute wear, extending tire life.

8. Low Tire Pressure

While it's normal for tires to lose a small amount of pressure over time, finding one tire significantly lower than the others indicates a leak. This could be from a puncture from a nail or other debris or due to a damaged valve stem or a broken seal between the tire and the wheel rim.

A simple way to find the source of a leak is to use a mixture of soapy water. Mix dish soap with water in a spray bottle and spray the mixture onto the tire, paying close attention to the tread, sidewalls and valve stem. If there's a leak, you'll see bubbles forming where the air is escaping.

Ignoring a slow leak can lead to a flat tire, so have your tire inspected by a professional as soon as possible (and have them check the tire pressure of the rest of your tires while you're there).

9. Knocking From the Engine

A knocking or pinging sound from your car engine can sound like a light tap or a more pronounced, rhythmic knock. While some engine noises are normal, a distinct knocking or pinging sound often indicates underlying car troubles.

One common cause is using fuel with a lower octane rating than recommended for your type of vehicle. This can lead to pre-ignition or detonation, where the air-fuel mixture ignites prematurely. It can also be due to a low engine oil level, leading to increased friction between engine components or loose engine components like connecting rods, pistons or bearings.

If you hear a knocking or pinging sound coming from your engine, have it inspected by a qualified mechanic to determine the appropriate repair.

10. Cracked Windshield

When it comes to windshield repair, minor cracks can sometimes be fixed, but larger cracks usually require replacement. Small chips or cracks smaller than a quarter can often be repaired with resin.

Larger cracks longer than six inches require full replacement. These weaken the windshield, compromising safety. Replacement involves removing the old windshield, cleaning the frame, applying adhesive and installing a new one.

11. Ignition Key Not Turning

A key that refuses to turn in the ignition is a frustrating car issue. There are several common causes:

• Worn-out key: If your key is worn down, it can prevent the ignition from engaging. Try your spare key, and if it works, you'll know the original key needs replacement.
• Locked steering wheel: To unlock a locked steering wheel, gently turn the wheel in both directions while trying to turn the key.
• Shifter not fully in آ€آœParkآ€آ‌: Ensure the shifter is securely in the "Park" position and try again.
• Debris: Apply a small amount of penetrating lubricant specifically designed for locks to your key and insert it into the ignition multiple times, gently wiggling it to distribute the lubricant.

If none of these solutions work, you may have a more serious ignition system problem requiring professional attention, such as a faulty ignition switch or cylinder.

12. Gas Mileage is Inefficient

Poor gas mileage can drain your wallet and indicate potential problems with your car. The best way to maintain better gas mileage is with regular vehicle maintenance to keep your engine running smoothly. This includes the following:

• Regular oil changes: This ensures proper lubrication and reduces friction within the engine.
• Replacing air filters and fuel filters: Clean air filters allow the engine to breathe efficiently, while clean fuel filters ensure a consistent flow of fuel.
• Maintaining spark plugs: Worn or fouled spark plugs can lead to incomplete combustion, reducing fuel economy.
• Proper tire pressure: Properly inflated tires reduce rolling resistance, improving fuel economy. You can check and adjust your tire pressure at home or at most gas stations.

Beyond regular maintenance, your driving habits and vehicle weight can also impact car engine efficiency. Aggressive driving habits (like rapid acceleration and hard braking) consume more fuel. Reducing unnecessary weight in your vehicle can also improve gas mileage.

13. Failed Emissions Test

A failed emissions test means your car emits excessive pollutants into the air. This is often due to a faulty oxygen (O2) sensor, which monitors the amount of oxygen in the exhaust gases and helps the engine control unit (ECU) create optimal combustion.

However, a malfunctioning O2 sensor isn't the only culprit. It could be operating correctly and sending accurate information to the ECU, which may indicate issues with the ignition system, such as a misfire. This can cause unburnt fuel (hydrocarbons) to travel through the exhaust system, passing over the O2 sensor, leading the ECU to compensate for the misfire. Similarly, problems with the fuel management system causing the engine to run rich can also lead to excessive emissions.

Other potential causes of emissions test failure include a faulty catalytic converter, a leaking exhaust system, or problems with the engine's computer system.

FAQs About Common Car Problems

Still have questions about common car problems? Find answers below.

What is the Most Common Car Issue?

The most common car issue is often a dead battery or a check engine light. Dead batteries are frequently caused by leaving lights on or extreme temperatures, while a check engine light can signal anything from a loose gas cap to a faulty oxygen sensor.

What is the Most Expensive Car Problem to Fix?

Major engine or transmission problems are among the most expensive car repairs. Issues like a cracked engine block, blown head gasket or complete transmission failure can require extensive labor and costly replacement parts, often totaling thousands of dollars.

At What Point Is a Car Not Fixable?

A car is typically considered not fixable when the repair costs exceed its market value or when critical structural damage makes it unsafe to drive. Extensive rust, a severely damaged frame or major engine or transmission damage in an older, low-value car often reach this point. In these cases, the cost of repairs outweighs the benefit of keeping the vehicle.

Stay Ahead of Disaster With AAA

Car troubles happen, but dealing with them doesn't have to be a nightmare. A AAA membership provides peace of mind with 24/7 roadside assistance, covering everything from jump starts and tire changes to towing and lockout services, so you're never stranded.