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Why is my car struggling to accelerate?

Charlotte Phillips, 1 year ago

3 min read

  • Advice
  • howto
  • why
Looking under car hood image

WhoCanFixMyCar offers five possible reasons your car isn’t accelerating properly and some of the symptoms you may find

When you've got somewhere important to be and your car is struggling to accelerate, not only is it frustrating, but it’s also potentially damaging for your vehicle if it goes unrepaired.

So what could be causing your car’s loss of acceleration, and how can you fix this problem to get your car back to its usual speed?


Why doesn't my car accelerate?

Clogged MAF Sensor

Blocked fuel filters

Slipped timing chain

Oxygen sensor problems

Catalytic converter failure

Why doesn’t my car accelerate?

A loss of acceleration feels like your car isn’t gaining the same speed as it once did when you put your foot down.

You will likely notice this change just from driving around yourself and feeling more resistance than you used to when pressing down on the accelerator pedal.

The best way to describe this feeling would be to imagine a weight has been added to your car, pulling you back and preventing you from gaining the same acceleration that you used to have, even though there's no immediately obvious cause.

This problem could be caused by a number of things, however, some of the most common reasons for your car struggling to accelerate are listed below.

What can cause acceleration problems in a car?

Clogged or malfunctioning Mass Air Flow Sensor

The Mass Air Flow (MAF) Sensor is situated in your car’s engine and has the job of telling your car exactly how much fuel is going through the engine. This allows your car to perform at its best by monitoring the exact airflow through your vehicle’s engine.

When the MAF Sensor becomes clogged or fails, it cannot measure the correct airflow through the engine, causing the wrong data to be sent to the engine ECU. This can cause damage to your engine, with one of the main symptoms being the car struggling to accelerate and pick up speed.

Blocked or dirty fuel filters

Blocked or dirty fuel filters are one of the common causes of a loss in acceleration in cars.

When a car is experiencing a blocked fuel filter, the engine won't get the amount of fuel that it needs, meaning you ultimately won’t be able to get as much acceleration as you should be getting.

Luckily, it's relatively cheap to get blocked fuel filters cleaned.

Slipped timing chain

The timing chain is one of the key components of your cars engine, and, as such, if the timing chain has slipped even slightly, it can instantly cause acceleration problems.

Timing chains need to be replaced between around 40,000 and 120,000 miles on average, but some smaller timing chain problems can also crop up between then which can be a lot cheaper to repair.

Oxygen sensor problems

The oxygen sensor in your car helps to regulate the air-fuel ratio going through the engine and sends this data to your car’s computer system. If this sensor becomes damaged or malfunctions, the engine will be unable to regulate the correct air to fuel ratio, and as a result, your car might struggle to pick up speed or hesitate as you accelerate.

Catalytic converter failure

The catalytic converter is important because it acts as a defence method against air pollution from our vehicles. The catalytic converter exchanges the harmful substances in your car’s exhaust fumes, such as carbon monoxide, for less harmful substances like carbon dioxide and water vapour.

While they should generally last around 10 years, the catalytic converter can become blocked, overheated, or generally damaged which will likely cause acceleration problems for your car.

As well as struggling to accelerate, you may also notice excessive heat and a burning smell from your car caused by catalytic converter failure.

If you notice any of these issues with your car, it could explain why you are experiencing a loss of acceleration. Though frustrating, we have a huge selection of garages in our network here at WhoCanFixMyCar who are able to fix these problems and get your car running at its usual speed.

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