10 Causes of a Car Losing Power When Accelerating

Car Losing Power Acceleration

Just like all mechanical types of equipment in this world, cars are also liable to damage.

If one of the important parts of your car’s engine gets worn out or damaged, it is a big chance that your car will lose power when accelerating.

Your car engine might not get enough fuel, or there might be a problem with the electricity supply to the engine.

In this article, we will discuss the various reasons why a car could lose power while accelerating.

A car can lose acceleration due to various reasons. Here are some of the most common reasons why it’s losing power. This list comply to both petrol and diesel engines.

10 Causes of a Car Losing Power When Accelerating

  1. Clogged Fuel Filter
  2. Clogged or Dirty Air Filter
  3. Clogged catalytic converter or particle filter
  4. MAF Sensor malfunction
  5. Oxygen Sensor malfunction
  6. Faulty fuel injectors
  7. Faulty fuel pump
  8. Low cylinder compression
  9. Faulty turbocharger/boost pipe leak

These are the most common types of causes for this type of problem.

Let’s continue to talk more about it. Here is a much more detailed list of the most common causes why your car is losing power while accelerating.

Clogged Fuel Filter (Both Diesel & Gas)

Fuel Filter

A fuel filter has the responsibility of filtering the fuel before it goes into the engine and combustion chamber. If the fuel filter gets clogged and the fuel does not reach the engine chamber in the right quantity, the engine will not perform at its optimum level.

You will feel as if you are losing power while you accelerate. So, when this happens, the first thing you should do is check your fuel filter.

The fuel filter is located in the engine bay or near the fuel tank in your car’s trunk. If the fuel filter is clogged, you can get it changed by a mechanic who will charge you a very paltry sum.

Clogged/Dirty Air Filter (Both Diesel & Gas)

Dirty Air Filter

The engine needs clean air to function properly. Dust and other particles can damage the combustion chamber. Therefore, the air that goes into the system should always be clean. To ensure this, an air filter is placed right before the throttle body.

As soon as the throttle opens, the air is sucked in, and it passes through the dedicated air filter, which cleanses the air of dust and other harmful particles. The air filter goes bad after a few thousand miles, so it is best if you get it changed every time you go for an oil change.

Clogged Catalytic Converter or Particle Filter

Clogged Catalytic Converter

The exhaust removes all the harmful and unnecessary gases from the engine. The sooner the exhaust excretes these gases, the sooner the engine can restart combustion.

Therefore, if the car can excrete gases faster than it produces them, the car runs fast and smooth.

However, if there is any obstacle in the way like a clogged catalytic converter or a clogged exhaust, then your engine loses power.

MAF Sensor Malfunction (Gas Engines)

Dirt Maf Sensor

The Mass Airflow Sensor (MAF) measures the amount of air the car needs to accelerate. Once it gets that measurement, it sends this information to the ECU, which notifies the throttle to open accordingly.

If the MAF is faulty and not measuring the airflow properly, you could experience a serious loss in power. Sensors can get worn out due to heat and dust. Regularly cleaning them can help improve their function.

Oxygen Sensor Malfunction (Gas engines)

Oxygen Sensor

The MAF senses the amount of air entering the engine, and the oxygen sensor measures the number of gases that exit the engine. It is therefore located in the exhaust pipe. If the MAF readings match with the oxygen sensor readings, then this means your car is in perfect running condition.

The oxygen sensor also affects the fuel injection system, so its proper function is necessary for your car’s smooth running.

If the oxygen O2 sensor fails, it can cause a lean condition in the engine, which will cause the engine to lose power when accelerating.

Faulty Fuel Injectors (Both Diesel & Gas)

Fuel Injector Location E1609829649410

Fuel injectors introduce fuel into the combustion chamber. They do this by sending in fuel at high-pressure, much like a spray. They need to spray the precise amount of fuel into the chamber for combustion to happen.

If there is even a slight miscalculation, the combustion cycle can get disrupted, resulting in loss of power and, in the worst-case scenario, broken cams or pistons.

Fuel Pump (Gas Engines)

Cars Fuel Pump

The fuel pump delivers fuel from the fuel tank to the engine. The fuel pump has to be powerful enough to be able to send the fuel at high pressure. If the pressure is low, the fuel injectors will not be able to spray the correct amount of fuel into the combustion chamber, resulting in a loss of power.

A faulty fuel pump will not pose problems at low speeds, but you might be left wanting when you are looking for quick acceleration. Fuel pumps usually have a long life, so checking the fuel pump on your car shouldn’t be your first action.

Worn Spark Plugs (Gas Engines)

Bad Spark Plugs

The spark plugs are part of the engine, which can cause problems with the engine’s power. They create the spark that causes explosions inside the combustion chamber. Without them, your car won’t even run.

If you are losing power, bad spark plugs could be a problem in some rare scenarios. Mostly you will notice worn spark plugs when your car is misfiring.

If your car engine doesn’t sound like usual, there is a chance that a spark plug is worn out and the car is running on one cylinder less than usual.

Poor Cylinder Compression (Both Diesel & Gas)

Car Compression Test E1609889560360

The cylinders in an engine have to be sealed tight so they can contain the explosions happening inside them. The car works on this basic principle. If the compression rate is high, then all the power from the explosion is being used to drive the pistons. However, if there is a leak, the compression rate drops.

In easier terms, this means that the cylinder cannot compress the explosion, and the power is not completely transferring to the wheels. This can lead directly to a loss in power while accelerating.

Faulty Turbocharger / Boost pipe leak (Both Diesel & Petrol)

Turbocharger

If your car is equipped with a turbocharger, your turbocharger is likely damaged. The turbocharger gives the engine a lot of extra horsepowers, and without it – your car will feel like a tractor.

An even more likely scenario is that a turbo boost pipe came loose, so the turbocharger will not increase the turbo pressure. This will cause a serious drop in the engine’s performance and cause the turbocharger to break.

Written by: Magnus Sellén

Founder, owner & main author of Mechanic Base. I have been repairing cars for more than 10 years, specialized in advanced diagnostics & troubleshooting. I have also been a drifting driver and mechanic for over 7 years.