Is it dangerous to drive your car with spark plugs misfiring?

The van has 155,ooo miles on it. It is still getting good gas mileage. Starting the car has not been a problem. I have just started noticing that it will jerk and sputter all of the sudden, especially when I try to speed up from relatively high speeds.

My car has 155000 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
To answer your question, yes it is unsafe to drive you car while you are having a misfire. I have provided an article written by one of our professional technicians below. https://www.yourmechanic.com/article/is-it-safe-to-drive-with-a-misfiring-cylinder.

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Continuing to drive on worn out or damaged spark plugs can ultimately cause engine damage, so don`t put it off.
I have just started noticing that it will jerk and sputter all of the sudden, especially when I try to speed up from relatively high speeds. My car has 155000 miles. My car has an automatic transmission. To answer your question, yes it is unsafe to drive you car while you are having a misfire.
Rough starts, hesitation and poor acceleration are all common symptoms of a bad spark plug. If a spark plug or multiple spark plugs are faulty, they will have trouble creating the spark that causes the ignition process in your vehicle.
A Toyota technician will determine the root of the problem – usually it`s down to worn spark plugs, a weak fuel injector or a vacuum leak, but there are other potential causes too. The source of the damage will determine how simple or complex a repair will be.
If left untreated, a cylinder misfire can lead to significant engine damage. Worse, if you experience a bad misfire while driving, it could result in an accident. This is why it`s important to treat engine misfires as soon as you detect them.
An under-torqued spark plug will not make full contact with the cylinder head. This reduces a plug`s ability to transfer heat and will result in elevated combustion chamber temperatures. Such temperatures can cause pre-ignition and detonation and lead to engine damage.
Finally, as mentioned above, if your oxygen sensor is going out you may experience engine performance problems such as sputtering and surging. The sputtering is caused when the engine control unit puts too much air in the combustion chamber.
A sputtering engine may just mean you need to have your fuel filter replaced. All vehicles have a series of vacuum hoses that create the fuel pressure. If one of them leaks or is damaged in any way, you will lose significant fuel pressure. The vehicle`s exhaust system can greatly impact the engine`s performance.
Improperly functioning spark plugs cause an uneven burn of fuel in the engine, resulting in fluctuating RPMs and a louder noise. You might also experience increased vibrations of your vehicle while sitting idle or while traveling at low speeds. These vibrations originate from the engine and can shake the entire car.
Problems With Your Throttle Pedal, Cable, or Position Sensor

If you are experiencing jerks in your car when accelerating, it might be due to a few reasons. The first reason is that the throttle pedal is not positioned correctly. The second is a result of the throttle cable being too tight or too loose.

A clogged or failed exhaust gas recirculation or crankcase ventilation valve or faulty oxygen sensor can send the wrong signals to the computer and cause misfires.
Engines that idle in a clunky or rough manner could be suffering from misfiring. In essence, when a misfire occurs and the air to fuel mixture in the cylinder becomes compromised, your engine essentially may jump up and down, causing your car to start and stop suddenly.
Misfires don`t simply go away – they need to be addressed immediately. Even if they don`t get worse, they certainly won`t get any better unless you take the car to a mechanic.
Without spark plugs, some vehicles won`t start — or go anywhere. Because the health of this car part is directly linked to engine performance, bad spark plugs can often lead to more significant problems, including prolonged cold-starting and misfires during acceleration.
An engine that hesitates or misfires instead of running smoothly may be attributed to faulty spark plugs. If the combustion process is interrupted, even for a moment, it can cause the performance of your engine to suffer.
What could the problem be? There are a range of reasons why your car is juddering when you accelerate. Your vehicle could have dirty fuel injectors, a damaged fuel pump, a blocked catalytic converter, a faulty mass airflow sensor, broken spark plugs, or even an accumulation of moisture.
Automatic transmissions that shift hard, jerk or shake during a shift change may mean your transmission fluid needs changed or fluid level is low. In manual transmission vehicles, abnormal gear shifts could indicate damaged gear synchros, worn clutches or other, more severe issues.
If the air/fuel mixture inside the engine becomes too rich, it can disrupt the exhaust, causing car jerks or the accelerator to respond when you press the gas pedal. Other symptoms of a faulty catalytic converter include foul odors and decreased fuel economy.
While the damage may seem small initially, the longer you drive with a bad oxygen sensor, the worse the damage will become. Eventually, you may experience rough idling, poor acceleration, engine misfires, an illuminated check engine light, and failed emission tests.
A clogged fuel or air filter can make your engine sputter and your acceleration lag because the engine is not getting enough fuel or air, respectively. The combustion chamber needs the correct amount of air and fuel in order to generate combustion efficiently.
If the fuel amount is too much or too little, the engine may begin to sputter. Your mass airflow sensor tells you how much air is in the engine. Just like the oxygen sensor, the engine will sputter if there is too much or too little air. Spark plugs are an integral part of your engine.
How many spark plugs are in a V6? Each cylinder needs at least one spark plug to ignite fuel, so most V6`s have 6 spark plugs. Some engines use two spark plugs in each cylinder.
FACT #4: YOU SHOULD CHANGE SPARK PLUGS EVERY 100K MILES OR SO. So, if good spark plugs are the key to avoiding these issues, how long do spark plugs last, exactly? The general rule of thumb about how often to change spark plugs is that they should be replaced after about 100,000 miles of driving.
There are a lot of things that can cause your car to chug and lose power. Dirty, old, worn out, clogged filters are a common cause of car sputtering and losing power. A clogged or failing catalytic converter can cause all kinds of problems for the engine, including sputtering and stalling.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Spark plug chaos. Rubber stoppers are preventing the spark plugs from coming out.
ANSWER : Hi there. Try using a pair of small needle nose pliers to pull off the rubber boots from the spark plugs. As you pull, twist the rubber boots to break them free. If you cannot get the rubber boots off, then try using some mineral oil on the boots to aid them off, then clean off the oil with soap and water with degreaser. If you need further assistance with removing the boots from the spark plugs, then seek out a professional, such as one from Your Mechanic, to help you.

Engine will not stay started. I have replaced idle control valve map sensor spark plugs spark plug wires no check engine light is
ANSWER : You have a problem with the distributor assembly. I recommend replacing the distributor assembly. This will replace all the possible sensors and coil for the ignition and fix the problem you have.

My car is shaking at idle and is losing power in the low end service engine soon light is flashing.
ANSWER : Engine misfires can be caused by many different problems and are generally caused by either a spark or fuel issue or in some cases, a combination of both. Spark related problems generally will result from things like ignition coils, crankshaft position sensor, spark plugs, spark plug wires or ignition modules not working properly. When the misfire results from a fuel related issue, this is commonly related to a lean fuel condition (lack of sufficient fuel supply to the motor). Fuel related misfires can be caused by many different things such as low fuel pressure, faulty or dirty fuel injectors, a faulty O2 sensor, a dirty or failing mass air-flow sensor, a faulty or dirty idle air control valve or a vacuum or intake leak. When the fuel supplied to the combustion chamber is insufficient, this results in an ignition (spark) that is igniting a less than balanced load of fuel and air. This results in a misfire or an explosion in the cylinder that is much less powerful than the other cylinders. This creates a loss of power that resonates throughout the motor additionally causing other problems with ignition and fuel timing. Due to the number of different things that may cause an engine misfire, the quickest and easiest way to diagnose this type of problem is to hook the vehicle up to a scanning tool which will download any potential fault codes that may have registered in the vehicle’s computer as a result of the poor running condition. I would recommend having an expert from YourMechanic come to your location to diagnose your misfiring problem.

There’s no spark when the car is in drive
ANSWER : Hello. This sounds like a computer issue. It sounds like there is either a short in the computer that is causing this or you are losing ground or connection at that cylinder. From my experience with Camaro’s the computer is usually at fault. It would need to be tested with an o-scope to tell which is the culprit. If you need help with this, consider YourMechanic, as a certified technician can diagnose your electrical issue firsthand and help you fix it accordingly.

Just replaced spark plugs and wires and my car is still miss firing and I can’t pin point why and my old spark plug is oil covered
ANSWER : Hello there, many faults will cause your 1988 Ford Contour to have a misfire even after the spark plugs were replaced. When oil is seen on the spark plug this indicates that the valve cover is leaking onto the plugs. When this happens it fouls the plugs and can cause a misfire. Until the oil leak is addressed the spark plugs will continue to become fouled. If the misfire persists there are many potential causes such as the plug wires, fuel pump, vacuum leak, oxygen sensor, MAF sensor, or the cap & rotor. A qualified Technician such as one from YourMechanic will be able to diagnose your misfire fault and make any repairs required to resolve the issue.

engine light-p303 cylinder 3 misfire, changed spark plugs,ingition coil and cylinder valves
ANSWER : Coils and plugs are usually the starting point for a misfire code, but some basic diagnostic work might save you some money. Sometimes I like to try swapping components from cylinder to cylinder to see if the misfire moves before buying expensive parts. There are a few other problems that could lead to a P0303, like ignition primary problems, vacuum leaks, or bad injectors, but those things are usually accompanied by other codes. It’s clear that you have a dead miss. When the ECU sees a consistent misfire, it shuts off the fuel to that cylinder to prevent damage to the catalyst. The the CEL will start blinking to warn you that you may be doing damage by continuing to drive. You’re at a point where you need to have a professional do some diagnostic work. by contacting Your Mechanic, you can have a technician come to your home or office to check out your misfiring VW and recommend a fix.

Car misfires after new spark plugs and multiple replacements
ANSWER : Hey there, thanks for writing in about your 1987 Pontiac Fiero. I have the 2.8L engine in my ’87 Cavalier Z24 and I know it well. I’m guessing your Fiero has the same engine. One of the best ways to narrow down potential misfire causes is to monitor the block learn multiplier and integrator parameters with an OEM scan tool.

These are close to the same thing as modern long term fuel trim and short term fuel trim, respectively. These values can help determine if the vehicle is running rich or lean, which will help narrow down the cause of the misfire.

The stoichiometric efficiency is 128, and anything less than that would mean the vehicle is running rich. Anything more would mean that it’s running lean. The integrator should vary somewhat once the vehicle is in closed loop, but should not get too far away from 128.

As far as the sticking valve goes, it may or may not be revealed during a compression test. I say this because, if the valve is closed during the test, but sticks intermittently, the compression readings will be OK. The next step would be to perform a leakdown test, which is more successful in pinpointing problems like a sticking valve.

There are too many things to list on a old car like this that could cause a misfire. My best advice is to have a professional, such as one from YourMechanic, diagnose and repair the misfire issue for you.

After part replacements, spark plugs do not work – 1996 Lexus LX450
ANSWER : If you have a Check Engine Light on, first check for those codes to determine what engine management thinks is going on. If no trouble code, check the ignition fuse behind the driver side kick panel (carpeted panel at foot level on the left – for left-hand drive vehicles). If the engine is spinning quickly, and doesn’t appear to be meeting any resistance (as a motor with good compression would have), you may have a broken timing belt. If so – STOP, call a professional mechanic, like a certified technician from YourMechanic for help.