Why does my car feel like it’s dragging when I accelerate?
This blog will answer the following questions: Why does my car feel like it’s dragging when I accelerate? Should you continue to drive if the car feels like it’s dragging? What to do if the performance of the engine is poor?
Why does my car feel like it’s dragging when I accelerate?
Your car can feel like it’s dragging under acceleration due to the following reasons:
- Clogged air filter
- Low boost pressure
- Weak/damaged engine mounts
- Jammed brake caliper/emergency brake.
Let’s take a detailed look at each reason and how to fix them:
Clogged air filter
The air in the intake manifold passes through an air filter before it reaches the throttle valve. The air filter removes moisture and dirt from the intake air and over time it can reach its limit. Manufacturers use multiple air filters depending on the displacement of the engine.
If the car is operating in a dusty environment, the filter can get clogged. As there is insufficient air available for combustion, the performance of the engine drops significantly. The car can feel like it’s dragging even when the driver is fully pressing the throttle pedal.
If there are no warning lights in the instrument cluster then either replacing or cleaning the air filter is a good way to check if the car feels normal. In some luxury cars, there are pressure sensors upstream and downstream of air filters to measure the contamination level.
This problem is more common in diesel engines because diesel engines require more air to operate than petrol engines. If the driver continues to drive the car with a clogged air filter, the engine control unit will store a fault code related to the air mass sensor.
Low boost pressure.
Most of the cars running today have turbochargers to compress the air and produce boost pressure. Turbocharging an internal combustion engine helps to reduce displacement while maintaining performance.
Therefore, if there is a low boost pressure in the system the car feels like it’s dragging. The internal combustion engine on its own cannot produce maximum horsepower. Without the boost pressure, the vehicle loses its throttle response and acceleration is poor.
An internal combustion engine can lose the boost pressure when there is a leak in the charge air intake system. The turbochargers are also controlled by wastegates, if the wastegate of the turbocharger is open due to a vacuum leak it will not spin the turbine wheel and there will be no boost pressure in the system.
The leak in the vacuum and the charge air intake system can be identified by visual inspection. An automotive smoke tester can also be used to check for small leaks in the system. Usually, the boost pressure leaks from cuts in the intercooler hose.
The leak in the Vacuum system can be due to the cracks in the rubber pipes which connect the vacuum cells to the transducers. Vacuum leaks can be difficult to identify because the pipes are not directly visible.
Weak/ damaged engine mounts
The internal combustion engine is mounted on the front axle carrier or the subframe. There are two engine mounts that support the engine and also absorb the vibrations. The engine mounts can get weaker with the age and mileage of the vehicle.
A weak engine mount does not allow the drivetrain to transfer all the power to the drive wheel. It also increases the NVH levels inside the vehicle. Due to the increased noise and vibrations inside the cabin, the driver can feel like the vehicle is dragging while accelerating.
If there are no fault codes in the engine control unit and the charge air intake system is leak-tight then the engine mounts must be replaced so that all the engine power is transmitted to the wheels.
Jammed caliper/ emergency parking brake
If the car feels like it’s dragging under acceleration then it is possible that the brakes are not fully released. There are service brakes and an emergency parking brake in the vehicle. The service brake can get jammed in a closed position which prevents the caliper piston from fully retracting.
If the vehicle has a floating caliper then rust or corrosion on the sliding pins can cause the brake pads to remain in contact with the brake disc. Similarly, the parking brake’s electrical motors can malfunction and engage the brakes.
If the brake pads can easily overheat and damage the brake disc, and the brake caliper. The car also cannot accelerate as the brakes can be stuck fully or partially. It is not safe to drive in this condition because the overheated brakes can catch fire and damage the vehicle.
Should you continue to drive if the car feels like it’s dragging?
No, if the car feels like it’s dragging it is not safe to continue driving until the problem is rectified. If there is a fault in the engine then the engine check light will be ON in the instrument cluster. Consult the nearest workshop to check the cause of the engine check light.
If the car feels like it’s dragging look for symptoms like a bad smell coming from the engine compartment, black smoke from the exhaust, and shift quality of the gears. The cost and time required for the repairs depend on the type of fault that is causing the drop in the performance of the engine.
What to do if the performance of the engine is poor?
If the performance of the engine is poor then perform the following steps.
- Read out the fault memory of the engine control unit with any OBD-II scanner.
- Check the service history of the vehicle and perform service if it is due according to the manufacturer’s specifications.
- Check the condition of the air filter and replace it if it is clogged.
- Renew the spark plugs of the engine and use the fuel system cleaner to clean the injector nozzles.
If the performance of the engine is still not good then the compression pressure must be checked. Due to high mileage, the piston rings get worn out. The compression pressure can start to leak and the engine loses its performance.
Similarly, if the cam profile on the camshaft is worn out, it prevents the valves from opening completely. Hence, the cylinder cannot be charged with the maximum quantity of the air-fuel mixtures and the car will feel sluggish.
This blog explained various reasons that can lead to poor performance of the engine. As the engine is not producing maximum power, the car feels like it’s dragging and it does not accelerate quickly. Periodic maintenance is important for the engine to keep its peak performance and maintain the reliability of the vehicle.