Car Jerks When Slowing Down – Here’s Why It Happens

Imagine you’re casually driving down the road and enjoying your routine music, and all of a sudden your car starts jerking when you applied the brakes. Well, you’re not alone as this is a very …

Car Jerks when slowing down

Imagine you’re casually driving down the road and enjoying your routine music, and all of a sudden your car starts jerking when you applied the brakes. Well, you’re not alone as this is a very common problem faced by most drivers, and they are usually caught off guard.  

Maintaining the car is vital for performance and keeping the mechanical components such as car battery, brakes, clutches in healthy condition is a must these days. If your car jerks while slowing down, you should understand that one of the many parts could have malfunctioned.

The jerks could either be very jolty, or have simple vibrations in the whole body of the car, but it needs your immediate attention and fixing by a professional technician.  

Let’s have an in-depth look at the different causes behind a jerking engine and jolty deceleration, and what should you do if your car jerks while slowing down. 

Why does a Car Jerk when slowing down? 

There could be many reasons behind your car jerking when you apply the brakes, and it could either be a major mechanical part at fault or simply a bad sensor. Let’s have a look at the most common reasons; 

Faulty Transmission 

As you try to slow down your car, the transmission will begin to downshift to adapt. If there’s something wrong with the transmission, the shifting will be jerky because the gears stumble and have a jolty movement to the lower gear. So you’d feel jerks in the car due to the transmission mounts transferring those to the body and a hindered car movement occurs. 

It could also be a defective torque converter as well, which is the component that controls how fast the engine and transmission interact. If the jerking occurs only at lower speeds, the torque converter is the most likely culprit. 

Leakage in the Gearbox 

If there’s leakage in the transmission, the whole assembly could heat up and lead to jerky shifting. this is mainly because there’s no lubricant to reduce the friction and allow the bearings to slide across each other smoothly. Transmission leaks can be caused by blown seals or damage to your car’s undercarriage. 

Worn Out or Damaged Clutch 

If you get these jerking motions while driving at lower speeds or in lower gear ratios, it can probably be a bad clutch on your car. To test, see whether the jerks go away when you slow down at higher gear ratios and if they reappear in lower gears. If the jerks are only occurring in lower gears, it is most probably the clutch that’s causing you the headache. 

Depending on the build quality, maintenance, and how roughly it is used, a clutch can easily last up to 150,000 miles. If your clutch hasn’t been replaced even after driving past 100,000 miles and its servicing had not been ideally ensured, it’s probably time for a replacement. 

Throttle Body Issues 

The air intake supply system in a car is controlled by the throttle body. If the throttle body gets damaged or there occurs a problem, the airflow system will not be able to effectively regulate the supply of air/fuel mixture into the engine. If the throttle body is the issue, the jerking movements normally appear when you are idling or driving at lower speeds. 

Faulty MAF Sensor 

The Mass Air Flow (MAF) sensor regulates the flow of air into the engine via the air intake. If there’s something wrong with the MAF sensor, either too less or too much air will be sent to the engine along with the fuel, hence disrupting the normal combustion process. 

If the MAF sensor is the culprit, you’d most likely experience a jerking motion in your car while slowing down. 

Some Other Probable Causes 

Apart from the main culprits, these issues can also cause your car to jerk when slowing down; 

  1. Damaged or worn-out engine and transmission mounts. 
  2. Damaged ignition coils. 

What Causes the Engine to Jerk? 

With so many parts moving in harmony and different processes going on, anything apart from normal can lead to a problem and cause the engine to jerk. Although the list could be never-ending, these are some of the most common issues that cause the engine to jerk. 

  1. Dirty Air Filter 
  2. Clogged Fuel Filter 
  3. Damaged Fuel Pump 
  4. Problematic Fuel Injectors  
  5. Faulty Spark Plugs 
  6. Damaged EGR Valves 
  7. Clogged Catalytic Converter 
  8. Faulty ignition system 

What to do if Your Car Jerks When Slowing Down? 

If you feel that your car has suddenly started jerking while slowing down, you’ve to act wisely and make sure you get the problem diagnosed and fixed. Keep the following points in mind to avoid any trouble and get safely back on the road in no time; 

Act Wisely – Don’t Panic 

The first and most important step is to control your nerves and don’t panic. The jerks can be accompanied by loud noises, so be calm and safely take your car to a garage or park it away from the traffic and rush, then call for help.  

Get the Transmission System Checked 

As discussed, a faulty transmission is usually the culprit behind jerky movements in a car. So have the system checked for leaks, loose mounts, or damaged parts and get it fixed. 

Get the Engine Checked Thoroughly 

So many components and filters in the engine are responsible for the proper functioning of the car, and any of these could be at fault. So calmly get all the parts scanned and let the expert technician diagnose the problematic component.  

Check the ABS 

A bad ABS sensor, module, or wiring can cause the car to jerk as well when slowing down. So it is important to have the ABS checked properly and the problem rectified. An ABS warning light also appears on the dash if there’s something wrong with the system. 

Get the Brakes Inspected 

The worn-out brake pads or damaged discs might be causing your car to jerk when you apply the brakes. Getting the brakes checked can get you out of trouble quickly. This comes after you’ve ruled out the obvious causes and the engine or transmission is completely fine.  

Final Thoughts 

Your daily drive partner is made up of thousands of parts, that work in harmony to ensure a smooth operation. Although you might be maintaining your car properly and there could nothing be wrong with your car apparently, a problem can occur anytime. 

If you feel continuous jerks while slowing down, there could be something wrong with your car, It could either be a bad sensor, a clogged catalytic converter, a bad air filter, or a huge problem like a faulty gearbox.  

It is important that you get your car diagnosed and the problem fixed properly, by an expert technician. Maintenance and regular checkup keeps your car in mint condition and can also help you avoid any surprises.