What makes a car lose acceleration

For old engines, maintaining compression can be a bit of challenge. There are several different ways an engine can lose compression:. One of the major things that can happen over time is the piston rings will wear down, and this will allow for blow-by. Some of the high pressure air and fuel mixture combusting will pass by the pistons and travel along the cylinder walls into the crank case. This is pressure that should be pressing the piston down, so power is lost.

It also means less compression as some of the air can escape as the piston travels upward on the intake stroke. With blow-by after combustion, the oil will contaminate much more quickly as the byproducts of combustion enter the crank case. If carbon deposits build up on the valves or valve seats, this can prevent the valves from closing properly. If an intake valve cannot fully close, it will allow air to escape during the compression stroke, effectively lowering the compression ratio.

Exhaust valves that cannot close properly will also result in a lower effective compression ratio. If deposits build on the piston or cylinder walls, these deposits can create hot spots.

These hot spots can result in engine knock if conditions allow for it. If the engine is capable, it will retard the ignition timing to reduce the likelihood of knock.

By retarding the ignition timing, power is lost. Spark plugs can build deposits with time. Without proper oil flow, components will wear much faster and will have to work harder to overcome the added friction. More wear, more friction, less power. The best thing you can do to prevent power loss over time is to properly maintain your vehicle. However, over time this can itself become clogged with all the excess material in the fuel system, impeding the flow of petrol or diesel into the engine.

Such a problem with the filter , will often show up when you are driving up a hill or trying to overtake a car — as you will not be able to achieve the power and acceleration you need to achieve. Fuel injectors can also become clogged with dirt over time, which prevents the proper flow of fuel into the engine.

It may also be accompanied by ignition, stalling and misfiring problems, and you may even become aware of the smell of fuel around your car. The diesel particulate filter or DPF can easily become blocked with particles. Many cars have systems where you can burn off the debris and particulate stuck in the filter at high speeds, but if you are only ever getting out into the gridlocked urban crawl this may not happen.

Some cars even have a system where the DPF will switch the car into a limp home mode. If this happens to you, then get to your local garage as soon as possible, to have the part cleaned. Your engine needs to clear out old exhaust gasses in order to take in clean air for combustion.

If your exhaust system is not working properly, this will in effect choke your engine and stop it from reaching full power. Some of the causes behind this could be:. No one wants to have a backfiring exhaust. These small explosions will cause you to lose power under acceleration. However, the cause of this issue will generally be somewhere in the fuel system — such as the fuel pump or the carburettor.

This can lead to the part becoming clogged, making it difficult for the exhaust gasses to pass through the intricate mesh of honeycombed precious metals that cleans out the harmful particles. Such a blockage will cause the exhaust gasses to become backed up in the engine.

The whole exhaust system is not immune from blockages. Old leaves, bits of grit and gravel or even rubbish papers and plastics, can get lodged in your exhaust and stop it from functioning properly. The turbo forces air into the engine at higher revs, giving it the extra oxygen it needs for increased combustion. Turbochargers can suffer from issue s, if there is a hole or lose connection in the tubing, which will impact performance. Similarly, it can get blocked up with leaves, rubbish and grit and needs to be cleared regularly.

Finally, the turbocharger is highly dependent on oil, so make sure that all your oil systems and filters are working properly. If your timing belt does not have the correct tension, or has been poorly maintained, this can cause your engine valves to open and close at incorrect intervals, resulting in poor engine performance.

This problem is one of the rarer ones on our list, and is accompanied by a tell-tale rattling coming from the engine. 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. 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.

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.

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.

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. 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.

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.

They create the spark that causes explosions inside the combustion chamber. 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. 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.