Cars are incredibly complex machines, with many parts needing to work in tandem to get your vehicle moving. However, there are occasions when the components of your car can stop working alongside each other, causing your vehicle to lose power.
In this guide, our motoring experts are here to explain what factors can cause power loss, how to identify the problems, and the ways the issues are fixed, so you can get back to driving safely on the road.
If you’re wanting to tackle these causes yourself, our extensive range of service parts has everything you need to deal with power loss, whatever the scenario.
Causes of power loss in cars
Spark plug
The spark plug is the literal spark of life in your car’s engine, igniting the fuel and air mixture to get the pistons, and your car, moving.
If the spark plug in your vehicle is damaged, this will result in unignited fuel traveling through the engine, causing it to misfire and your car to lose power.
Replacing your car’s spark plugs can be done at home, with the assistance of a ratchet spanner.
Blocked fuel filter
A fuel filter is essential for preventing harmful debris getting into the engine of your vehicle and throughout the system.
Naturally, if the fuel filter becomes blocked over time, the fuel can’t enter the engine to be combusted, therefore it prevents your car from getting the power it needs.
Changing a fuel filter should be done every two years to keep your car’s fuel system clean and clear from blockages.
Clogged exhaust
Another part of your car that can become blocked is the exhaust. This can occur due to debris, such as leaves, finding their way into the exhaust pipe and preventing the release of combustion gases.
The exhaust can be easily cleared though by using an old towel or cloth with soapy water. Once the exhaust pipe has been cleaned, apply degreaser to remove any rust and small accumulated blockages; then remove the degreaser with some steel wool.
Fuel injector
Your car’s fuel injectors can clog-up over time, ultimately stopping them from injecting the crucial fuel needed to power up the engine.
You can clean the fuel injectors with specialist cleaner, based on whether your car engine is petrol or diesel. Check the bottle and add the specified amount into the fuel tank when it’s almost empty.
Backfiring exhaust
A backfiring exhaust (indicated by a loud bang when you’re accelerating) can be a reason why your car is losing power. Not only that, but it can suggest an issue with the car’s fuel pump, which if it is, you need to get checked immediately by a qualified engineer.
Catalytic convertor
Another source of power loss in a car, and a further part that can become blocked over time, is a vehicle’s catalytic convertor.
When you’re driving, any harmful pollutants in the exhaust are converted into water and other less harmful gases. If the convertor is blocked, these gases can’t go anywhere, meaning your car can’t rev to its full potential.
A clogged convertor will need replacing by a garage to ensure it is thoroughly cleaned and installed safely.
MAF (Mass Airflow Sensor)
Working closely alongside the fuel injector is the Mass Airflow Sensor. Sitting between the air filter and intake manifold, the MAF sensor calculates how much air is in the engine; this is vital for ensuring your car’s engine has the right fuel/air mix for combustion.
A faulty MAF sensor means the correct air measurement is not being delivered to the engine’s electronic systems, resulting in a reduced power output.
To replace the MAF sensor at home, disconnect the electrical connector and use a screwdriver to remove the old sensor from its clamps. Then, insert the new MAF sensor, followed by reconnecting the clamps and the connector.
Poor pressure
If there are any gaps or leaks in an engine’s valves, this can cause a poor level of compression in the car’s cylinders, which negatively impacts how much power is produced by your vehicle.
For a thorough check, ask an engineer to examine all of your vehicle’s engine valves to ensure there are no pressure leaks.
Timing belt
An engine’s valves may also be opening and closing at incorrect times, due to a misaligned timing belt (cambelt).
This essential engine part opens in sync with the pistons, and connects the crankshaft and camshaft together.
If you feel your car is losing power while you’re driving, it’s a good idea to ask a local garage if there are any issues with the alignment of your vehicle’s timing belt.
Limp Mode
The engine warning light is an indicator of a serious issue with your car’s engine. It also means it has potentially entered ‘limp mode;’ a security feature which cuts off power to the parts of the car that the computer deems less important, such as the air conditioning.
‘Limp mode’ deliberately staggers car performance during a fault, so this is often a clear indicator of why your vehicle is losing power.
If you see the engine warning light appear, take your car to an engineer as soon as possible to find out what the problem is.
Overheated systems
Any part of a car that is needing to work harder than normal, such as the cooling system, will inevitably be drawing more power from the rest of the vehicle. This is a tell-tale sign of power loss in cars, and should be checked by an engineer to identify any potential faults.
Checking for signs of power loss in your car is an essential part of car maintenance. If you want to know what a car service includes, and how often your car needs one, our experts explain everything you need to consider before booking it in for a service.