How to Figure Out Why Your Car Won’t Start

Posted on April 24, 2025 by Autohaus

Nothing is more frustrating than jumping into your car, turning the key (or pressing the button), and… nothing happens. Your car won’t start. Whether you’re rushing to work, heading out for errands, or picking up the kids, a car refusing to start is a situation no one wants to deal with.

There are plenty of potential culprits, from something as simple as an empty fuel tank to more complex issues like a faulty starter motor. Understanding why your car won’t start and knowing the proper troubleshooting steps can save you time, money, and stress.

This guide breaks down the common reasons for car starting problems, how to diagnose them, and practical advice on what to do next.

Call 317-571-0800 if Your German Car Won't Start in Indianapolis Indiana — Call 317-571-0800 if Your German Car Won’t Start in Indianapolis Indiana

Typical Car Starting Problems

Battery Issues

The battery is the heart of your car’s electrical system. When there’s a problem, your car won’t start—but diagnosing the issue is simpler than you think.

Dead or Weak Battery

A dead or weak battery is one of the most common reasons why your car refuses to start.

How to Check

Turn the key to the “ON” position and check the dashboard lights. If the lights are dim or don’t turn on, it’s likely your battery.
Use a multimeter to measure the voltage. A reading below 12.4 volts means the battery is weak.

How to Fix It

Jump-start the car:

Connect the positive (+) terminal of the dead battery to the positive terminal of a working battery.
Attach the negative (-) terminal of the working battery to an unpainted metal surface on the car with the dead battery (not directly to the battery).
Start the working car and wait a few minutes, then try starting your car.
Have the battery tested at Autohaus Dierolf to determine if it needs replacement.

Corroded Battery Terminals

Even if the battery isn’t dead, corroded connections can block electrical flow.

How to Spot It

Look for white or bluish-green buildup around the battery terminals.

How to Fix

Disconnect the cables (start with the negative). Use a battery terminal cleaner or baking soda mixed with water to remove the corrosion.
Reconnect the cables securely.

⚙ Pro Tip: Regularly clean the terminals to prevent recurring issues.

Starter Problems

If your battery checks out but your car still won’t start, the culprit may be the starter motor.

Faulty Starter Motor

The starter motor is responsible for cranking your engine to get it running.

Signs of a Starter Problem

A clicking noise when you turn the key.
Dashboard lights dim significantly when you try to start the car.
A burning smell or smoke (rare but critical).

Quick Fix

Try gently tapping the starter with a wrench while someone else attempts to start the car. This can temporarily “unstick” the solenoid.

If these steps fail, the starter motor likely needs professional repair or replacement.

Schedule Automotive Diagnostic Testing Today

Fuel System Issues

Even the most powerful engine won’t run without fuel. Problems in your car’s fuel system can lead to frustrating starting issues, but most of them are easy to diagnose and fix.

Empty Fuel Tank

It may sound obvious, but overlooking this simple issue is common. Sometimes, drivers misjudge how much fuel they have left or forget to refuel.

What to Do

Check your fuel gauge. If it’s low or empty, add fuel and try starting again.
If needed, add fuel and try starting the car again. If the car still doesn’t start, there could be another issue at play, such as a problem with the fuel pump or fuel line.

Clogged Fuel Filter

The fuel filter plays a crucial role in keeping debris and impurities from entering the engine. Over time, it can become clogged, restricting or completely blocking the flow of fuel. This can lead to serious performance issues or prevent the car from starting altogether.

Signs

The car starts but stalls quickly.
Poor engine performance when running.

Solution

Replacing a fuel filter is routine maintenance.
Check your service schedule to avoid this problem in the future.

Malfunctioning Fuel Pump

The fuel pump transfers fuel to the engine. If it fails, your car won’t start.

How to Check and Fix

Turn the key to the “ON” position and listen for a whirring sound near the fuel tank. If you don’t hear it, the pump may be faulty.
A qualified mechanic can run a fuel pressure test to confirm the issue.

Ignition System Faults

The ignition system is vital for creating the spark needed to ignite the engine’s air-fuel mixture.

Bad Spark Plugs

Worn or fouled spark plugs are a frequent culprit in cars that won’t start.

What to Do

Remove the spark plugs and inspect them for damage or deposits.
Replace worn or damaged spark plugs with new ones.

Faulty Ignition Coils

Ignition coils generate the high voltage needed for the spark plugs to work. If you suspect ignition coil trouble, have them tested at Autohaus Dierolf for accuracy.

Symptoms

Engine misfires
Reduced fuel efficiency

Other Potential Issues

While battery, starter, fuel, and ignition problems cover most cases, here are additional possibilities for those experiencing persistent trouble:

Faulty Car Computer (ECU)

Modern vehicles, especially complex ones like BMW, Volkswagen, Mercedes-Benz, and Porsche, rely heavily on an Engine Control Unit (ECU). If the ECU malfunctions, it can confuse the starting system.

Solution

Visit Autohaus Dierolf for a car diagnostic service to pinpoint the issue.

Anti-Theft System Issues

Many German cars have advanced anti-theft systems. If activated unintentionally, they may prevent the car from starting.

What to Do

Look for the anti-theft symbol on your dashboard. If it’s flashing, your system may need to be reset according to your car’s manual.

Avoid These Common Mistakes When Troubleshooting

Overlooking obvious issues like an empty fuel tank.
Incorrect jump-starting that damages your car’s electrical system.
Neglecting corroded battery terminals, which is often a quick fix.
Ignoring warning signs, like clicking or whirring sounds.
Assuming it’s always the battery without testing it first.
Replacing parts unnecessarily without verifying the root cause.
Postponing professional diagnostics, which can save you from more expensive repairs later.

Take Action to Get Back on the Road

Car starting problems are stressful, but knowing the common causes makes troubleshooting manageable. Whether it’s a weak battery, a failing starter motor, or a clogged fuel filter, addressing these issues early can prevent bigger headaches down the road.

If your car won’t start and you’re unsure why, schedule a diagnostic service at Autohaus Dierolf today. Our expert mechanics in Indianapolis specialize in German cars like BMW, Volkswagen, and Audi, and will get you back on the road quickly and safely.

Book Your Appointment Now

How Does Tire Width Affect Gas Mileage in Cars?

Posted on February 25, 2021 by Autohaus

Today, everyone is looking for the answer to better gas mileage. Vehicle owners and drivers are on a constant hunt for secrets, miracle cures, rises in the economy, and blatant luck to reduce gas mileage, prices, and fuel consumption. There are several reasons why vehicles can get good or bad gas mileage. There are so many factors that affect this area of concern; however, there is one variable that is hardly discussed but highly influential when it comes to fuel mileage. This variable is tire width. Tires have a large influence on how a car or truck operates on the road.

Continue reading to learn how tire size can affect fuel economy and gas mileage on the road.

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The 101 on Gas Mileage and Tire Care

There are two things to consider when thinking about tires and their effect on gas mileage; one is wind resistance, and the other is rolling resistance. When a car is driving at higher speeds, it experiences higher wind resistance; this means lower fuel economy. Rolling resistance is the impact the road has on the tires, and how it affects drivability. If you change the features (size and width) of your tires, it will then influence the interaction it has with the road, thus affecting the gas mileage. This is where tire width can begin to influence gas mileage.

Tire Size and Width Influences Gas Mileage

Many people believe by changing the height of a car’s tires, they can increase its fuel economy. This is not a reliable idea. You see, speedometers are specifically calibrated to the number of revolutions a set of tires makes per mile while driving. If the original set of tires is replaced, the calibration will be off and changes in fuel economy will be blurred. Shorter tires will calculate at higher gas mileage because they will make so many more revolutions per mile. This negatively affects fuel consumption because it makes the car’s engine work at a higher rpm to achieve the same speeds. Taller tires will do just the opposite while still offering an inaccurate reading.

Tire Width versus Gas Mileage

Tire width is one of the only tire size factors that can influence gas mileage in a positive way. For example, a narrow tire will have less wind resistance, rolling resistance, and weight, thus, increasing gas mileage. If choosing a narrower tire, be aware that they can make the car’s handling characteristics more difficult to control. It is best to always install the proper size tires for your particular vehicle. A professional tire tech or mechanic will have no problem helping you figure this out. Also, keeping your tires fully inflated can improve gas mileage.

Do you need fuel system repair or factory scheduled maintenance for a European car in Carmel, Indianapolis, IN? Contact Autohaus Dierolf at 317-571-0800 for the best deals around town!

More Reads to Check Out:

Top 5 Car Parts Affected By Cold Weather
How to Start the New Year With Better Fuel Mileage
Routine Automotive Services Recommended Just for European Vehicles

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The Seven Essential Automotive Fluids Every Vehicle Needs

Posted on July 23, 2020 by Autohaus

When it comes to car care, your vehicle needs more than just a run through the neighborhood car wash every now and then. In adherence to most manufacturer’s instructions, it is important to service your vehicle’s tires, engine, lighting system, battery, and more. But undeniably, one the most vital maintenance practices you simply cannot neglect are your vehicles essential automotive fluids. There are seven automotive fluids that every vehicle needs to operate safely, or at all for that matter.

Continue reading to learn which 7 automotive fluids every vehicle needs, and where to get trusted Indianapolis car maintenance and advice.

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➀ Motor Oil

Motor oil is one of the basic, primary fluids that all vehicle’s need to operate safely, or at all. Motor oil is intended to lubricate the moving parts inside a car engine’s crankcase. Without it, an engine will quickly overheat, causing the vehicle to break down. This is because all the moving parts within a car engine creates friction, which produces heat. The lubrication reduces this friction, which in return, prevents overheating. Motor oil protects an engine’s pistons, valves, and all its other moving parts. Have your oil changed every 6 months or 5,000 miles, more or less depending on how much you drive.

➁ Brake Fluid

The ability to stop a vehicle is just as important as the ability to make it go. Just like motor oil, brake fluid is also one of the most important fluids for any vehicle. A car’s brake system uses hydraulic pressure to make a vehicle come to a stop. When a brake pedal is pushed, the brake line system compresses the brake fluid, which then allows the hydraulic force to be transferred to the brake pads and rotors where the friction is made that stops a vehicle. If there is a leak in this system, or no brake fluid at all, a vehicle loses its capacity to stop upon request. Brake fluid must be re-filled on a regular basis. The general rule is to have your vehicle inspected for all fluid changes and replacements, as well as other factory services, every 3 to 6 months depending on how much you drive and the age of the car or truck.

➂ Radiator Fluid (Coolant or Anti-Freeze)

Radiator Fluid, also called coolant or anti-freeze, is extremely important for your car or truck. It is a heat-transfer liquid that prevents a motor from overheating. It does this by cycling through an engine and collecting heat as it flows; and then returns the collected heat to the radiator, which is then filtered and released through the exhaust and muffler. A car is not operational if it overheats. Operating a car without coolant can cause irreversible damages to the engine and other parts of the vehicle, as well as, put passengers and drivers in danger. Adding anti-freeze to your engine is simple and can be done on your own. Simply locate the radiator cap, unscrew, and our in store-bought pre-mixed coolant. Be sure to have your car’s radiator flushed annually by a professional mechanic.

➃ Transmission Fluid

Transmission fluid is not a solution that requires a car owner to check on their own. Professionals typically tend to these types of fluids when facilitating regular scheduled maintenance tasks. Transmission fluid is rust-colored, or almost a reddish hue. It is used to lubricate and cool the inner components of a vehicle’s transmission, similar to motor oil.

➄ Power Steering Fluid

Power steering fluid is also typically checked and administered by a professional automotive technician during routine factory care. Power steering fluid is pressurized by a small hydraulic pump that is powered by the engine. Its main responsibility is to make turning a car easier. It increases the functionality of the steering mechanism that directs the car tires while driving on the road.

➅ Battery Fluid

Many vehicles today are manufactured with maintenance-free batteries; however, some older models will require a vehicle owner to manually replace the battery fluid on a regular basis. In these type of vehicle batteries, the individual cells need to be filled with the proper type of battery fluid in order for the vehicle to run.

➆ Windshield Wiper Fluid

Although commonly overlooked, a driver could almost not live without windshield wiper fluid! Mud, dirt, water spots, insects, fingerprints, and more can be distracting on a vehicle’s windshield. Windshield wiper fluid is a soapy viscous solution that can be controlled manually by a push of a button inside the car. This button or attachment is generally near the steering wheel. Depending on how often it is used, windshield wiper fluid should be refilled every few months or so.

Auto Repair and Factory Scheduled Maintenance in Carmel, Indiana

Call Autohaus Dierolf at 317-571-0800 to request a free estimate, or to schedule an appointment, for European auto repair or factory scheduled car maintenance in Carmel, Indiana. Our German factory-trained mechanics provide a wide range of automotive maintenance and repair services for all European make and model vehicles. Best of all, we offer free written estimates and extensive warranties on all our work. Don’t wait another minute to get your needed automotive work done. Call our office today to get started.

Summertime Automotive Care Advice to Live By

Posted on July 9, 2020 by Autohaus

Although the damaging winter snow and salt can be rough for cars and trucks, summer weather can equally take a toll on your vehicle as well. The combination of high temperatures and general wear and tear can negatively affect several vital components of a vehicle, including the battery, tires, radiator, and more. This is why it is critical to remember safe and effective auto care in the summer heat.

Continue reading to review some helpful automotive care tips to keep your vehicle running smoothly this summer!

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Car Battery Service

High temperatures and overcharging can cause the battery in your vehicle to drain faster, shortening its life. This is because heat can cause battery fluid to evaporate quickly, consequently damaging its internal structure. To avoid such problems, have your vehicle serviced regularly by a licensed mechanic who can make sure your electrical system is charging at the correct rate. For car batteries that require “topping off”, it is necessary to check the levels more often in hot weather. Keep in mind that dirt is another cause behind battery power loss. So be sure the top of your battery remains clean, since dirt and corrosion can interrupt current flow.

Radiator Service

Another important component to service properly in summer heat is your car’s radiator. High temperatures cause the cooling system to work harder, therefore relying on the radiator fluid more. Simply be sure that your radiator fluid is always a 50:50 mix of coolant and water, and routinely have your radiator flushed and refilled once every year to support an optimal cooling system. During routine radiator service, your mechanic will complete a comprehensive visual inspection, and then run a pressure test, thermostat test, cooling fan test, and more. And remember to never open a radiator cap that is hot to the touch!

Tire Service

Your tires will certainly wear out more in hotter weather since they experience more stress in such conditions. This is why tire service and tire care are important for summer. Be sure your tires are inflated properly, and check them regularly for structural damages. Have a professional auto shop service your tires every 6,000 miles with tire rotation and balancing, inflation, replacement, and more.

Auto AC Service

An auto AC system is designed to control the interior climate of a vehicle, including temperature and humidity, and comes in many different forms depending on the make and model of the car. Routine auto AC service is a critical part of preventative maintenance for your vehicle. Not only does it provide the proper inspections and replacements necessary for every summer, it prevents future breakdowns and costly repairs.Keep in mind that a refrigerant leak is damaging to the ozone layer. Not only does a properly-functioning AC system save on gas mileage, it is environmentally friendly.

Trusted European Car Repair Service in Carmel, Indiana

Call Autohaus Dierolf at 317-571-0800 for European auto repair and service in Carmel, Indiana. Our German factory trained mechanics have more than 30 years of experience specializing in European make and model vehicles. We provide a wide range of automotive repairs and services, including factory scheduled maintenance and auto repair. Call 317-571-0800 for affordable and reputable auto maintenance in Carmel, IN today.