Why Is My Car Losing Power? Troubleshooting Engine Issues

There are clear signs that your engine is losing power. Your vehicle might not be accelerating as hard as it did before. Perhaps your vehicle has felt slower when it’s climbing hills or when it’s carrying cargo. If this is the case, then there’s a good chance that your vehicle has a problem.

Reasons Why Your Engine Is Losing Power

There are a lot of issues that can cause loss of engine power. A clogged fuel filter was a very common culprit in carburetor engines. Now, modern fuel systems don’t have frequent fuel filter issues anymore. However, a wide range of other components can still cause power loss when they develop issues.

What causes a modern car to lose power? The most common problems include faulty fuel injectors, fuel pumps, spark plugs, and air filters.

If your car is losing power while driving, it’s typically accompanied by other engine-related symptoms. You should note these other symptoms because you can use this information to find the root cause behind the power loss.

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Symptoms Alongside Power Loss

An engine that’s losing power will also likely show one or more of the following symptoms:

Unresponsive Throttle Pedal

The most obvious sign that the engine is losing power is an unresponsive throttle pedal. You might notice this symptom when you’re accelerating and the vehicle isn’t responding appropriately. You might also notice this when you’re driving uphill and your vehicle can’t reach its usual speeds.

When the throttle pedal is unresponsive and there aren’t other symptoms, then the problem might lie with your vehicle’s fuel system. Parts like the fuel line might be clogged, or the fuel pump might be supplying insufficient fuel pressure.

Engine Misfires

An engine misfires when there’s a problem with combustion in one of the cylinders. This can be a lack of ignition, a weak ignition that fails to burn the air-fuel mix fully, or an ignition attempt that occurs at the wrong moment in the engine cycle. A cylinder that misfires won’t create as much power.

Engine misfires are typically quite apparent because you can feel and hear them. A misfiring engine is going to create vibrations and popping or cough-like noises from the exhaust.

Engine misfires are typically caused by problems with the vehicle’s ignition system, such as fouled-up spark plugs that aren’t igniting fuel properly. However, a faulty fuel system or engine air filter can also cause this problem.

Engine Knock

Engine knock occurs when the air-fuel mixture in the combustion chamber ignites prematurely. This creates downward pressure on the piston during the compression stroke, which causes your engine to lose some of its rotational energy.

Aside from causing reduced engine power, engine knock also creates a metallic pinging noise. Engine knock can also damage engine components like pistons and valves.

Excessive Vibrations

An engine that has issues with its fuel or ignition system can cause excessive vibrations during idling. An engine that isn’t producing enough power can get to the brink of stalling when it’s sitting idle. When this happens, the engine is going to excessively vibrate.

Smoke Belching

When your vehicle belches smoke, it means your engine is running rich, which means there’s too much fuel in the air-fuel mixture. Pumping too much fuel isn’t an efficient or effective way to produce power. It’s similar to drowning your engine in fuel. It’s going to result in a lot of unburned byproducts, which come in the form of dark smoke coming out of your vehicle’s exhaust.

A smoke-belching vehicle can have issues like a fuel injector that’s pumping more fuel in the combustion chamber. Alternatively, the intake valves might not be allowing enough air to enter the combustion chamber.

Excessive Fuel Consumption

Whenever an engine has issues such as engine knock, smoke-belching, and misfires, there’s a good chance that the engine is excessively consuming fuel. An engine with issues is going to be more inefficient compared to an engine that’s functioning properly.

Illuminated Check Engine Light

Your vehicle’s onboard diagnostic system can detect many of the previously mentioned issues. Once detected, your diagnostic system is going to activate your vehicle’s check engine light located on the gauge cluster.

If your check engine light illuminates, then diagnosing the cause of your engine’s power loss is going to be easy since you can just plug in a scan tool and check for stored trouble codes. An illuminated check engine light combined with reduced engine performance can point to a wide range of issues such as faulty oxygen sensors, spark plug wires, or positive crankcase ventilation valves.

If none of these issues accompany your vehicle’s power loss, then your catalytic converter might be to blame.

If your vehicle is losing power, you must recognize its associated symptoms so that you can diagnose and address the underlying issues. Promptly address these symptoms so that you can keep your vehicle running properly and avoid further engine damage.