Reasons a car jerks driving at low or constant speeds

Buying a car is easy, but its maintenance is the hard part. Your car requires constant attention in terms of washing, detailing, polishing, servicing, and lots more.

Article summary

Dirty injectors and car engine parts are the most common reasons that a car jerks at low or constant speeds while driving. However, some other reasons include the following:

  • Spark plug issues
  • Distributor caps condensation
  • A new car part


If you’re missing some maintenance pointers, your car will surely remind you in the worst ways. One of these is experiencing car jerks while driving. In this article, we lay down all the reasons a car jerks at low or constant speeds while driving.

Keep reading so you can save yourself some hassle!

Table of Contents

Reasons a car jerks driving at low or constant speeds

There could be several reasons a car jerks driving at low or constant speeds, and we cover them all below.

Dirty injectors

car injectors

While cars look smooth sailing on the outside, what goes on inside the engine is beyond a layman’s understanding. But we’ll try to sum it up.

Fuel is used to power vehicles. They must burn it to create energy. However, this practice leaves the engine’s insides prone to grime and dirty leftovers from the burning. If any dirt gets on the fuel injector, it’s natural for the car to jerk.

A direct comparaison between dirty and clean fuel injectors can be seen in the following table.

Dirty Fuel InjectorsClean Fuel Injectors
FunctionDecreased fuel efficiencyImproved fuel efficiency
CausesBuildup of carbon over timeRegular maintenance and cleaning
Repair CostsInexpensive if caught earlyLess expensive than dirty fuel injectors
MaintenanceRegular cleaning recommended to prevent buildupRegular cleaning recommended to keep fuel injectors working

Some signs that your injector might be dirty are the jerking you experience when the car is cruising at normal speeds. Another sign is the vehicle losing power while cruising.

Solution: You can avoid this phenomenon by regularly cleaning the fuel injector yourself. A car cleaning kit for the fuel injector can be bought at most garages. Buy one with PEA cleaning fluid.

Regular cleaning can avoid sky-high repair costs.

Dirty engine parts

car engine

Apart from the fuel injector, other parts could also be causing car jerks in the engine. Your fuel filter can get clogged from the burning fuel grime.

If you are somewhat acquainted with the parts of an engine, you can uninstall, clean, and refit it yourself. But you should call a professional if you are a first-timer.

It might help to give the engine a good cleaning once in two or three months. Exceptionally dedicated drivers do this because they know the benefits. It doesn’t hurt to start now if you haven’t already!

Spark plug issues

spark plug wires

If the car jerking is happening just as you start driving, the issue could be with the spark plug. Imagine you pushing a lighter that sparks a flame, which you use to light a candle.

It is somewhat the mechanism of a spark plug. The most common issues with spark plugs are shown in the following table.

Buildup of carbon or oilEngine misfires and poor acceleration
Gradual erosion of the electrodeReduced fuel efficiency and decreased power
Overheating of the spark plugEngine knocking and difficulty starting the engine
Oxidation of the spark plugPoor acceleration and engine misfires

The battery is used to ignite the spark plug. In turn, it ignites the fuel. The fuel starts burning, and the car comes into motion.

But if the spark plug is dirty or faulty, this can’t happen. You’re expecting an unlit lighter to light a candle.

There are several spark plugs. Some may be working while others aren’t. However, if you replace some and leave others, you might encounter the same problem again. The older plugs will stop working while the new ones stay intact.

That’s why you should consider replacing all the spark plugs at once. However, do check once to see if cleaning them will do the trick.

What are the signs of car jerking?

First off, let’s learn how to recognize car jerking. If you’re driving normally at constant or low speeds and experience a motion forward that can only be explained as if you just hit the gas and let go suddenly – that is a car jerking.

There can be several reasons for this, but you must identify the frequency and the circumstances of the jerking. Does it happen when you speed up? Does it happen when you start the vehicle?

Does it randomly happen as you drive at a uniform speed and catch you off guard? The answer has a lot to do with the solution.

When driving at a constant speed

Sometimes you don’t even hit the gas, and the vehicle seems to have a mind of its own, and the car jumps. We cover some of the reasons for this below.

Condensation in distributor caps

distributor cap

If you live in colder areas, parking a vehicle overnight could cause moisture to form inside distributor caps. Water might seem harmless, but it can cause engines to misfire when accelerating at low speeds.

You can park your vehicle in a garage or porch area to avoid this. If this is not possible, you could buy a thermal cover easily. It will ensure your vehicle stays protected from any additional heat and damage as well.

Engine mounts coming loose

The engine mounts keep the chassis connected to the engine. Sometimes this can get worn out and disconnected. When engine mounts come loose, it causes your engine to rev at lower speeds.

If this certainly is the case, it might need replacement. Only get this done by a trusted and qualified professional as the engine will need due support from beneath during the job- it certainly isn’t an amateur task!

Fuel running out

We’ve got some good news and bad news. The good news is that there might not be anything wrong with the car.

The bad news is that you forgot to feed it, and now you must fetch some fuel for it to start again. Thankfully the car isn’t like a pet that reacts dramatically to a feeding being missed.

But this might mean you are getting stranded in the middle of nowhere with no gas for miles. So always pay attention to the fuel meter before going on long drives.

A new part

You left your car at the garage for servicing, and now that you’re driving off after retrieving it, it feels different. Sure it is shiny and new-looking. But the smoothness of the drive isn’t the same.

A new installation could be a problem if the vehicle stutters and spurs when stopped or accelerating.

You’ve got new parts installed like new spark plugs or a rack and pinion steering, and the car is jolting with a mind of its own.

We recommend you head to a trusted mechanic (a different one) and get the work checked steadily.

If the new parts are not installed properly, they could cause malfunction. They could even result in other parts of the car being damaged.

Some fluid under the car

Are you noticing some unwanted red fluid under the car? The Check Engine light is also on and stays on. That’s exactly what you need to do.

Get the vehicle checked by a professional mechanic. Loose bolts and unhinged drain plugs as well might be causing the leaking of the transmission fluid. It will cause the car to go into jumping mode occasionally.

Here are some properties of the transmission fluid.

LubricationHelps lubricate various components of the transmission
CoolingHelps cool the transmission and prevent overheating
CleaningTransmission fluid contains additives that help to clean the transmission
Seal protectionKeeps the seals and gaskets soft and pliable

Your engine will be stuttering, spurting, and not working at its best until you get this fixed.

Keeping the transmission fluid intact will cause the engine to work at its prime. It will also increase the life of your ride by several years!

When stopped in the drive’?

There could be a few reasons for this. However, all are fixable. You should get the problem diagnosed quickly and work on it fast before any accidents happen.

Problems with the clutch

In a stick shift car, the clutch is of even more importance. It is used frequently and wears out fast because of the constant gear changing.

If you are new to this, it could be the car jolting is caused by your awkward gear-changing. The experience may smoothen out after more familiarity with the car.

However, your clutch could also be worn out and defective. The pressure plate could be the problem. Sometimes oil leaks to the clutch plate and causes even more problems.

Simple wearing out and aging of the car can also lead to clutch trouble. It can be fixed with a quick trip to the mechanic.

Bad clutch control

The driver can also be the culprit of a vehicle jolting on its own. If you’ve got less control over the clutch or you’ve just shifted to a stick shift car, you might need to learn to smoothen the process of changing gears.

Changing gears can be tricky if you’re new to it. Just learn to hold down the clutch all the way and don’t let go until you fully change the gear.

The stick also needs to be shifted fully and in one go. If you leave it midway, the vehicle will make a screeching noise until you put the stick in any one particular gear. Any delay or fault in this process will make the vehicle jerk.

Problem with the brakes

While stopping, the most important mechanism being used is the brake. If the car isn’t responding well to stopping, an obvious sign could be the wearing out of the brakes. It’s worth getting your brake lines checked out.

The anti-lock brake system must be in place and running smoothly to accommodate a smooth landing in your driveway.

An issue with the brakes is a big deal and must be attended to as soon as possible!

Why you should trust us?

Car jerking is not something we take lightly. We’ve talked to the experts and read several online research articles that state what we’ve listed for you above. And above all – personal experience was our biggest asset when writing these tips.

How much does it cost to fix?

If the issue is a small one like a dirty air filter, it should be cheaply done within $150. But if a larger part is to be replaced like the brake lines, this will cost you between $200 – $300. Any major intake system replacement will be upwards of $500.

Factors to consider

There are several things to consider before you go for a repair though.

The age of the car

Were you thinking of buying a new car anyway? If yes, then why bother with the expensive repairs on this one. However, if not, you should go ahead with the repairs but in the budget friendly manner that suits you best.

Where to get repairs

You’re likely to wonder where the repairs will be performed. If your car started giving you trouble right after servicing, chances are they didn’t check thoroughly enough. You would want to change your repair guy and go to someone the reviews suggest is trustworthy as well as worth your money.

We will be happy to hear your thoughts

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