There’s no better feeling than lifting your foot off the brake, punching the gas, and watching your car pull away into the distance. Unfortunately, sometimes, this experience is hampered by a sudden juddering of the car when you do this. This can be rather annoying and scary at the same time – especially if you drive a manual. That is why we have written this article to explain why a car jerks when accelerating from a stop.
If your car jerks when accelerating from a stop, the most likely cause is a worn clutch. It may be because of the friction plate or even the pressure plate. In such cases, you might have to replace the concerned part. However, other problems such as ignition system issues, airflow problems, and even fuel line clogging can cause your car to jerk when speeding up. These problems can easily be fixed by cleaning or switching a part of one of those systems.
In most cases, this problem is nothing too severe and can easily be fixed. However, it is important to pinpoint the exact problem. Otherwise, there might be a chance of the problem snowballing and becoming something worse. Time to look in detail at what can cause this juddering of a car.
In manual cars, before you start, you must shift the gear to first before re-engaging the clutch. Often, due to high levels of stress or misuse, the clutch plate gets deformed, and the lining loses its grip. This causes rough re-engaging of the clutch when you try to accelerate your car from start. Moreover, your pressure plate might be damaged too causing similar issues.
To confirm this diagnosis, you need to pay attention to how the car vibrates during every gear change. If you notice the behavior is common during all gear shifts, then it is probably a problem with the clutch plate. You will have to take the clutch out to check whether the friction lining is the issue or the pressure plate.
Once the root cause is identified, you merely need to replace the respective part and you should be good to go. This can be a rather tricky fix; thus, it is best to let a mechanic handle the assembly and disassembly process.
Sometimes, an oil leak onto the clutch plate can also cause slipping and thus resemble such a problem. At such times, the source of the leak needs to be fixed and the lining needs a thorough cleaning for normal operation to resume.
If you notice the car jerks when accelerating not just during gear shifts, but other times too, then the problem may lie with the sparkplugs. In this case, you might feel the vibration even when the car is idling. A slight loss of power is also expected.
Over time, the extreme heat causes the sparkplugs to distort. They cannot form proper sparks every cycle due to this. Ultimately, this leads to the misfiring of the engine and unbalanced power causing the juddering.
Fortunately, replacing the sparkplugs is super easy and rather inexpensive too. They are situated right at the top of the engine and are easy to access. Generally, they are also replaced during certain periodic maintenance. So, if you ensure they are, you can prevent this problem altogether.
Clogged Fuel Systems
Ruling out the previous two problems, you might want to check the fuel lines. Several spots in the fuel system can cause a lack of fuel supply. Again, this leads to unbalanced power, and hence your car jerks when accelerating. A way to check if this is the problem is to observe the emissions. If the exhaust smoke is blackish then there is a high chance that there is carbon being burnt.
In the fuel system, the most likely candidate is usually clogged fuel injectors. You could try to clean them or replace them entirely. This is quite easy to do and inexpensive as well. The next suspect to check is the fuel filter. It often gets clogged due to impurities. Fuel filters are generally changed during routine maintenance to prevent such problems.
Finally, the last thing to check is a malfunctioning fuel pump or fuel lines. Fuel pumps can malfunction and blow the fuel pump fuse too. In such cases, sometimes you just need to replace the fuel pump.
Air Intake System
Along with fuel systems, the air systems can also cause problems related to the jerking of the car. The two main things to look for are the Mass Air Flow (MAF) sensor and the air filter. The former causes juddering by messing up the air-fuel ratio while the latter does it by reducing the flow of air to the engine. Either of these problems would also cause a noticeable drop in the engine performance.
Air filters can often get clogged due to outside dust and debris. It is quite easy to clean or replace them depending on the extent of the damage. Generally, they are replaced during maintenance as well.
On the other hand, MAF sensors can read the wrong amount of airflow, leading to an imbalanced air-fuel ratio and ultimately unbalanced power. This may be why your car jerks when accelerating. You can easily replace this MAF sensor as well to solve your problems.
Clogged catalytic converters
These converters are responsible for keeping your emissions within legal limits. However, they can often get clogged due to debris from the intake system or soot generated due to combustion. Because of this, the engine has to exert more pressure to push the exhaust gasses out. If this is done in bursts, you might feel that your car is juddering.
To help solve this problem, you will need to clean the catalytic converter. This might be slightly tricky if you don’t have a mechanical engineering background. Otherwise, with a good cleaner, you should be able to clean it without damaging it.
An alternative is to replace the catalytic converter altogether but that might end up costing quite a pretty penny. Ultimately, it depends on the life of the vehicle and how much more you are willing to invest in it to solve this problem.
Other Uncommon Issues
Aside from the ones listed above, if you have an old car, the reason it jerks while you accelerate might be different. For example, older cars used distributor systems to generate sparks. Moisture accumulation during winter months in the distributor cap caused the misfiring of the plugs leading to the vibration.
Alternatively, sometimes the accelerator cable used to get too lax. This led to the throttle valve not opening enough for acceleration and not staying open long enough either causing the random bursts of power.
In the first case, you need to take off the distributor cap and let it dry properly before starting the car again. For the accelerator cable, you will have to tension the cable properly or change it depending on the condition. If you are unsure about any of these processes, you can ask a mechanic to help you out.
As you can see, there can be a multitude of reasons why the car jerks when accelerating from a stop. Fortunately, most of these problems are rather mild and can be fixed fairly easily. Moreover, they are usually not too expensive either. So, you can simply do it yourself or let a mechanic handle it. However, it is important to get the problem looked at soon because it might be hinting at some underlying problem that is worse. Hopefully, this article shed some light on the problems and that you never face this problem ever again.