If your car jerks when slowing down, there shouldn’t be too much to worry about. The reason for this is that many people encounter this problem at some point, and it can be a stressful experience for some people, especially for drivers without any experience in driving.
There are a number of reasons why your car jerks when slowing down. The purpose of this article is to inform readers about what causes jerking when slowing down in vehicles and how to fix this issue.
Why Does My Car Jerk When Slowing Down?
If a car jerks when slowing down it is possibly caused by a transmission fluid leak, failing transmission, worn engine mounts, worn clutch, leaking engine mounts, damaged turbo, or a faulty torque converter.
When a car jerks when slowing down it is about the feeling created rather than the sound the vehicle makes. There is this feeling of vibrations that occur rapidly. It almost feels like the vehicle is gasping for air.
Frequently, when a car jerks when slowing down, it is usually caused by an imbalance in the fuel and air passed into the engine. Various components and parts of the engine may also be responsible for this imbalance; hence, troubleshooting is quite necessary.
Furthermore, when the tires or brakes have a problem, it may also lead to a situation where the car jerks when slowing down. A clogged fuel filter may also be the cause.
The fuel filter takes out dirt and keeps it out of the engine; however, when it is not clean, it is usually unable to act as resistance for dirt and other particles. Consequently, they enter into the engine and are capable of causing unexpected car jerks when slowing down.
The mass airflow sensor determines the balance of fuel and air being passed into the vehicle’s engine. When a sensor failure occurs, an imbalance is created between the air and fuel, which could lead to excess fuel or less fuel in the engine.
This is also capable of causing car jerks when slowing down. A throttle position sensor may also be responsible for jerking in a vehicle when a throttle position sensor is faulty. This sensor determines the Throttle’s position, and when it fails, it could also cause jerking in a car.
Lastly, a poorly aligned or damaged tire can result in car jerks when slowing down. A little thing like a nail, glass, or metal can cause enough damage to a tire and cause misalignment.
Also Read: RPM Going Up And Down At Idle (Causes & Solutions)
Other Reasons Why a Car Jerks When Slowing Down
1. Failing/Faulty Transmission
In several cases, a transmission failure is a reason why a car jerks when slowing down. Shifting between gears will not be a smooth operation when a transmission fails or becomes faulty.
Consequently, the car jerks when downshifting due to the failure to switch gears. The simple way to fix this is to have the transmission examined by a professional mechanic and when a fault is discovered, have it fixed immediately.
Another thing responsible for car jerks when slowing down is when the torque converter gets faulty. This component (torque converter) constitutes part of the transmission and helps regulate the work rate of the transmission and the engine.
If a torque converter fails or becomes faulty, it could cause car jerks when slowing down, especially when a vehicle is being driven at a low speed. The transmission fluids should be checked to confirm whether they are in adequate proportion or if they need to be topped.
2. Leaking Transmission
As stated above, transmission is the major reason a car jerks when slowing down. It can also make the vehicle perform terribly when driving at a low speed, especially when the vehicle has transmission problems.
Leakage is a common issue with transmissions and can cause car jerks when slowing down. Inspecting the underneath of the vehicle to check for any visible leak is highly recommended; if any leakage is found, check on the nearest mechanic for assistance.
Also Read: Transmission Fluid Leak When Parked (Causes & Solutions)
3. Worn Clutch
If a vehicle’s clutch wears off, it may also lead to car jerks when slowing down. A damaged or worn clutch leads to the engine revving up even at a low acceleration due to the worn clutch.
A way to know if a worn clutch causes the vehicle to jerk is to check for any irregular sound or vibration that may occur when driving at low acceleration. Some components of the clutch can also be changed to know what exactly is wrong with the clutch and fix the same accordingly.
4. Throttle Body Problems
The throttle body is a constituent of the vehicle’s engine. It regulates the quantity of air going into the air intake system, which controls the quantity of air being passed into the engine.
In several cases, a lousy or faulty throttle body can result in car jerks when slowing down due to its inability to regulate air and fuel passed into the engine.
When the throttle body of a vehicle is damaged, there will be issues with idling at a low speed because it cannot regulate the quantity of fuel going into the engine.
5. Damaged Mass Air Flow Meter (MAF)
The engine component measuring the quantity of air entering the vehicle’s engine is known as the mass airflow meter. Suppose the MAF sensor should become defective or get damaged.
In that case, its duty to regulate the right quantity of air that goes into the engine is not carried out, which will result in the vehicle moving inappropriately when driving at a low speed.
A professional mechanic should inspect and repair this issue, and a few tests can be carried out to know if the MAF sensor has any problem whatsoever.
6. Damaged Coil Packs
Another popular issue that can make a car jerk when slowing down is when the coil packs are faulty. Damaged or faulty coils can make a vehicle move badly when driving at a slow speed, especially if the coil packs have not been changed in a long time.
Fortunately, it is not a difficult problem to fix; changing coil packs can be done by the vehicle owner, or a professional mechanic may be engaged to assist with this task.
7. Worn Mounts
Worn engine mounts could another reason a car jerks when slowing down. Engine mounts keep an engine in one position when the engine is working, and in a situation where it wears out, the engine does not shake or vibrate as it should due to the wearing out of the mounts.
It may become necessary to run a vibration test to detect what could have gone wrong with the engine mounts. Changing engine mounts may be the answer to the jerking problem of a vehicle when slowing down.
8. Damaged Turbo
In a few instances, when a turbo in a vehicle gets damaged, it can cause car jerks when slowing down. A damaged turbo will cause the engine to move at a speed different from its normal speed, and consequently, the vehicle jerks when slowing down.
In situations like this, a vehicle requires a professional mechanic to examine the level of damage and repair any crack found on the turbo case, if any is found. Sadly, this is an expensive repair, although it is possible to repair, and the vehicle returns to normal after such repair is concluded.
Also Read: Car Temperature Gauge Stays on Cold (Causes & Solutions)
What Should I Do When My Car Jerks When Slowing Down?
Taking a vehicle to a mechanic’s shop to service it is an essential thing to always remember. Several components could get damaged, which includes every part mentioned above and even some other components.
1. Reflect on Your Gear Shifting (Manual Cars Only)
If the vehicle is manual, it puts such a driver among the minority and a decreasing majority of drivers in Europe and the US. The jerking may be experienced due to poorly timed or uneven shifting.
Professional manual vehicle drivers do not usually go through this jerking experience. However, if a driver is going through this, a reason for this could be that such driver is driving a manual vehicle after a very long time.
Some repair costs could be saved by simply having an expert driver check the shifting to know if it is wrong. The driver himself can also check it. Do these jerking motions occur during downshifting?
It is important to eliminate these factors first if you drive a manual car.
2. Have the Brakes Inspected
After ruling out the major cause, other causes should be considered. First among those other causes are the brakes. Inspect the brakes carefully and service them if necessary.
Minor problems that could lead to issues with the brakes include air in brake lines, which is easy to fix through bleeding the brakes.
There may also be the need for new brake pads. A squealing sound may also be heard while slowing down. In a very serious case, the smooth surface of brake rotors may deform due to overly worn brake pads.
3. Have the Transmission Serviced
A faulty transmission could also be the problem. Fixing this issue as fast as possible is quite critical. This is so because repairing the transmission is like changing torque converters.
It is quite a huge task as the transmission of a vehicle is among the most complex and intricate systems. Nonetheless, these repairs are necessary for the vehicle.
Hopefully, inspecting will result in simple issues like a low quantity of transmission fluid, which can easily be filled as a quick fix to such an issue.
4. Have the ABS Inspected
The anti-lock brake system (ABS) could also be responsible for decelerating a vehicle. Have you seen the ABS warning indicator showing on the dash display?
It could be a sign that the vehicle’s ABS sensor is faulty, a bad connection, buildup of particles, or other problems capable of distorting its regular operation.
5. Most Importantly – Don’t Panic
It is important to remember that with little regard to how bad a vehicle jerks or the type of sound it makes, never panic regardless. Stay calm and continue driving with care, slowly and at a steady pace, till it has safely been parked at least, or drive carefully to a mechanic’s workshop if possible.
If such an occurrence takes a toll on the safety of the vehicle, find a secured location and pull over; after that, look for roadside assistance as that could be a way to get the vehicle out of the way.
Also Read: Brake Pedal Squeaking (6 Causes & Solutions by Expert)
Frequently Asked Questions – Car Jerks When Slowing Down
Why does my car keep jerking when I brake?
When the brake rotors are deformed or no longer balance, the vehicle may jerk when slowing down or experience rapid vibration, depending on the driving conditions. If it is a problem of a worn brake pad or brake pads full of dirt and particles, there is an art of the brake rotor beneath the brake pads that can gather these substances, which could cause the vehicle to jerk when slowing down.
Why does my car jerk when accelerating and decelerating?
An unclean fuel injector is part of the usual reasons why an accelerator jerks. Such a dirty injector makes the vehicle lose power when trying to speed up after slowing down or when driving at a particular speed. This is a consequence of a misfiring engine.
Why does my car stutter when I stop?
A very common reason for a stuttering engine is the car’s fuel system ( including the pump, filter, and injectors.) These components of the system are critical and work hand in hand in making sure fuel circulates smoothly through the engine’s fuel injectors and pumps into the engine from the fuel tank.
Can transmission cause a car to jerk?
The transmission control module regulates shifting while accelerating; hence, a delay may occur while shifting, which is capable of making a vehicle jerk. Although it does not occur as frequently as other problems mentioned, it is equally capable of causing a vehicle to jerk.
Is it safe to drive a jerking car?
A surging or jerking vehicle at high speed can be quite dangerous, especially during bad weather or heavy traffic. If it is noticed that while accelerating, a vehicle jerks, then do not drive such a vehicle and ensure a professional mechanic looks at it.
Conclusion – Car Jerks When Slowing Down
We have explained the most popular reasons why a car jerks when slowing down. Other factors may also be responsible for this problem; however, the more regular causes are the ones listed above.
If a vehicle jerks when decelerating, try to fix the problem following the procedure given in this write-up. Getting a professional mechanic to assist in solving this problem is highly recommended if uncertain about how to handle the diagnosis.