Why Does My Car Lose Power?

By Max. D Gray. Updated: February 14, 2017
Why Does My Car Lose Power?

Why does my car lose power? In most cases, a loss of engine power is related to a mechanical failure in your vehicle; however, a loss of power may also be due to an external factor such as high temperatures.

If your car loses power while you are driving, there may be a variety of different reasons why. In this oneHOWTO article we'll help you diagnose your car's problem yourself, offering a number of possible answers to explain why does your car loses power and giving you some tips on how to fix the problem.

You may also be interested in: Why Is My Car Engine Light On

Does your car lose power because of a fuel injector?

Your car may lose power if an injector has poor contact with the internal combustion engine. If this is the cause of the problem, you will notice an exaggerated vibration in the motor.

We recommend that you maintain these parts well. It can be done by a mechanic, but you can also learn how to do it by yourself by reading our article how to clean a fuel injector at home.

Why Does My Car Lose Power? - Does your car lose power because of a fuel injector?

Does your car lose power because of the turbo engine?

If your car's model is among those which have a turbo engine or turbocharger, something that is increasingly common, you may find that this element is the reason why your car loses power when you drive.

It may be that a tube connector of the turbo engine is damaged, or simply dirty or poorly adjusted. This fault can also occur because the valve that regulates the turbo does not work properly. Here you can learn how to maintain a turbo diesel engine.

Why Does My Car Lose Power? - Does your car lose power because of the turbo engine?

Does your car lose power because of the AC system?

If you turn on the air conditioning system when you drive, your car will lose power. You will notice this especially when you go on a road trip, or with smaller vehicles used primarily for city driving. If you are overtaking while going uphill and have the air conditioning on, you will notice how the engine can feel like it is losing power.

There is no need to worry, but be aware that the air conditioning system will use of some of your engine's available power factor when driving.

Here you can learn how to clean your car's AC system, how to recharge it at home, and how to get rid of bad smell from car air conditioner.

Why Does My Car Lose Power? - Does your car lose power because of the AC system?

Does your car lose power because of the cooling system?

The cause of your car's power loss could also be an overloaded internal combustion engine cooling system. In extreme conditions generated by very high external temperatures, the car's fan has to act at peak performance. This takes away power to the rest of the engine equivalent to about 2 hp.

Here you can learn more about why is my car thermostat going up and down.

Why Does My Car Lose Power? - Does your car lose power because of the cooling system?

Does your car lose power because of an error in the ECU?

For cars with an ECU (Electronic Control Unit), an error in this embedded system can cause the car to lose power. In some cases, the car may stop completely.

This fault, which is not easy to solve, often happens because the ECU system detects a mechanical error in the car that doesn't actually exist. Therefore, the ECU gives the command to lose power or stop to the engine in order to prevent an accident although there is no reason to do so.

In most cases, ECU failures get fixed on their own and you will be able to use your car again after half an hour without a problem. However, you should go to a professional to repair the unit so that it does not fail again.

Why Does My Car Lose Power? - Does your car lose power because of an error in the ECU?

Does your car lose power because of the catalytic converter?

If your car loses power when you accelerate, or if it accelerates more slowly than usual, it could be that your catalytic converter may be blocking gases and thus not allowing your car to rev like it should: here you can learn more about why doesn't your car accelerate properly.

To check if your car is losing power because of the catalytic converter, you'll only need to pay attention for a rattle-like sound when you tap the catalytic converter lightly with a hammer or similar. Visit a mechanic if this is the case or clean the catalytic converter by yourself at home.

Another reason why your car loses power when you accelerate or doesn't accelerate at all when you press the acceleration pedal may be because your fuel filter is bad.

Other possible car problems

If as well as experiencing a loss of power you have noticed that your car jerks or makes a sound like an airplane, we have plenty of other articles to help diagnose your specific issue.

Do you know other reasons why a car loses power? Tell us in the comments section and help out other readers!

If you want to read similar articles to Why Does My Car Lose Power?, we recommend you visit our Car Maintenance and Repair category.

Write a comment about Why Does My Car Lose Power?

What did you think of this article?
Billy Kingdon
2015 toyota aygo still under warranty. Has an intermittent fault where it loses power when driving, and also won't accelerate or pull away. Also sometimes if you stall it doesn't restart, and when it does it won't rev for several minutes. Toyota main dealer say nothing is wrong, but the car is almost undriveable!
OneHowTo Editor
Hi Billy,

It is very hard to diagnose without being in front of the car, but it sounds like it could be a problem with the starter motor. The Toyota Aygo is generally a fairly sound car with little specific problems related to the 2015 model. However, we have heard of starter problems in older models. If you know how to listen out for the solenoid, it could help. This is what sends electrical current to the starter. If you can't hear it, this is likely the problem. Here is some more info you can read:

It depends on your warranty, but if your car is under warranty and you have a problem, you should be able to press the dealer on the matter (although always be polite, rudeness rarely helps in these discussions). We can't guarantee the starter is the problem, but if it is, then it would explain why it is malfunctioning at some points and not others.

We hope this is helpful!
My car lose power, when am at the stop light with the AC on.
OneHowTo Editor
Hi Ronnie,

Have you been able to consider the possibilities listed in the article?
Jerry D Frerichs
I have a 2009 Suzuki Equator. The vehicle would not go faster than 10 MPH and would not start again after I cut off the engine. The cam sensor and computer box has been changed. It still will not start. The radiator fan will turn.
jim paterson
focus 1.6 2003 drives good on flat road but struggles on hills,have to go down to third and sometimes second and this is with no luggage,pedal to floor
c hind
I have just replaced my glow plugs on my Renault scenic 1'9dci with a shorter one will it affect the engine performance
my car is a polo 2003 model,the mileage right now is started to loose power lately when atmospheric temperature is very hot and it is travelling long even stops and after some time to cool off,it then goes well.the temperature sensor says the engine temperature is ok
my car vauxhall zafira 2.2 petrol ,when i start the car first time i got sign car with spanner and i loses power to go ,but when i switch the car off and switch on again the sign car with spanner despair and the car drive normally .anyone know whats the problem.Thanks
Ruby Russell
I have a 2004 Volkswagen beetle and just put a new battery in ,, for about a month though whenever I push the gas to go it doesn't wanna go. I tap it and it goes fine.. Some days it doesn't act up.. What could it be
i have a hyundai getz 1.4 2008 its been losing power.i have change the fuel filter in tank.due to every one saying its needing fuel .it ,went great the same day next morning i have no power cant even get the car to move and my foot is flat on fuel
Have a 2005 turbo diesel manual terracan. Recentlty I have noticed vehicle loose power for about half a second then comes good. Not warning lights show. Prior engine had a stutter when idling. Can you advise

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