What Can Cause a Loss of Power in My Car?

A lot of common automotive problems have no noticeable symptoms. Oil or coolant leaks will not immediately impact the way your car drives. A seemingly serious issue like a check engine light can even occur with no changes in drive ability.

Sometimes problems present more noticeably. Noises from your suspension when you turn or press the brakes, a new smell, or loud engine operation are common. One of the most noticeable changes in driving dynamics is a loss of power. Unfortunately, there are many potential causes for power loss, making it a tricky diagnosis. In this article, we are going to go over some of the most common causes of this complaint.

Engine Operation

Before we look at the causes of power loss, we need to understand the basics of engine operation. Internal combustion engines require oxygen (air), fuel, spark (gasoline only), and compression to run. Loss of engine power is normally a result of an issue relating to these basic requirements. The complexity of modern vehicles means the potential causes are numerous, however.

Fueling Issues

The fueling system in your vehicle has several components that can have a direct impact on engine power.

Fuel Filter

The fuel filter prevents contaminants from getting into the fuel system, protecting the fuel lines and injectors from damage. Clogged or dirty fuel filters can cause a reduction in engine power. Some vehicles have serviceable fuel filters, and some have a screen built directly into the fuel pump. Filters that can be serviced should be changed every 50-60 thousand miles. Older cars should have fuel filters changed more frequently, as gas tanks can degrade and contaminate the fuel.

Fuel Pump

The fuel pump is responsible for moving fuel from the tank to the engine and providing the pressure and volume needed for optimal operation. A failing fuel pump can result in a drop in engine power or complete engine shutoff.

Fuel Injectors

Modern vehicles use fuel injectors to spray fuel into the engine through port or direct injection. Injectors allow fuel to enter the cylinder and mix with air before combustion. When a fuel injector becomes clogged or fails, you will notice reduced engine power and even misfires.

fuel injector out of car

Air Intake Issues

Fuel and air need to mix before combustion. Air is supplied through the intake system. Issues preventing fresh air from getting into the engine can result in a noticeable loss of power.

Dirty/Clogged Air Filter

The engine air filter keeps debris and dust out, but after thousands of miles, they become less effective and can even stifle the engine. Changing your air filter will prevent it from causing performance issues.

Throttle Body Problems

The throttle body controls the amount of air entering the engine when you press the gas pedal. If it becomes dirty or stuck, you can experience sluggish or jerky acceleration.

Close up of throttle body

Turbocharger and Supercharger Problems

Some vehicles employ forced induction to provide the engine with denser, compressed air. Superchargers and turbocharges allow for more power to be squeezed out of smaller engines and can improve fuel economy. 

Turbo removed from car

On forced induction vehicles, any issue with the turbo or supercharger can cause a significant power loss. If the air is not compressed to the correct PSI, the engine won’t make full power until it’s repaired or replaced.

Spark and Compression Issues

Lastly, inadequate spark or compression can result in a loss of engine power. There are a few potential causes of problems with spark

Coil Packs 

Most modern cars use a coil-on-plug system to activate the spark plugs. If a coil pack fails or has issues, the spark plug may not fire.

Spark Plugs 

Spark plugs ignite the air/fuel mixture on gasoline engines. If they are not changed regularly, they are not as effective at their job and can cause reduced engine power, rough running, and bad fuel economy.

Low Compression

During normal engine operation, the air and fuel mixture is highly compressed in the cylinder before combustion. Bad head gaskets, failed pistons rings, damaged pistons, or problems with valves and valve seats are some of the more common causes of low compression.

Red head gasket removed from car

Limp Mode

Sometimes, a fault can cause your car to go into limp mode. Limp mode is meant to protect your vehicle from damage while you drive to a repair shop or dealership and will cause a substantial drop in engine power.

Diagnostics is Often Required

With so many potential causes of reduced engine power, it’s hard to pinpoint the cause of the issue without digging into the car. If your car is feeling sluggish, the best thing you can do is visit your local repair shop.

Get Your Car Serviced at Becker Service Center

Is your car having problems? It may be time to visit a repair shop! Becker Service Center is your one-stop for all things auto repair. Our Naperville repair shop is staffed with ASE Certified technicians with years of experience. Give us a call or schedule an appointment online today!