Can Bad Spark Plug Cause Car To Shake?

Spark Plug

It’s never a good sign if your car experiences uncontrollable vibrations. It’s neither safe nor comfortable, especially if you drive long distances. Luckily, cars have several vibration-reducing elements, like shock absorbers, springs, and bushings, to reduce unnecessary shaking.  

However, your vehicle can experience excessive vibration even after having these components. When that happens, you should start worrying. Perhaps it’s the engine mounts, the spark plugs, or the cambelt.   

Can Faulty Spark Plugs Cause Car To Shake?  

Faulty spark plugs can produce excessive vibration in the engine that can, in turn, cause the car to shake. If this issue is left untreated, you could seriously damage the suspension system and possibly the entire vehicle in the long term. So, it’s best not to delay going to the mechanic for repairs. Or else, the last stop would be to sell your vehicle for cash for cars Canberra if the damage becomes uncontrollable.   

Research suggests that the car’s floor panels are one of the first areas to experience vibration along with the suspension components. Although the suspension arm takes the lion’s share of the vibration, the shake in the floor panels must not be overlooked. Little by little, the vibrations chip away at your car, and in a few years, the effects start to show.   

In such matters, you must consult a professional. But before you go anywhere, it can be beneficial to partially self-diagnose the issue.   

How Do Bad Spark Plugs Cause Vibration?    

The engine in your car produces power when a mixture of air and fuel ignites. The resulting explosion drives the pistons, which trigger the drivetrain, and the tires move.  

An electric signal triggers the spark plugs when the air/fuel mixture enters the combustion chamber. They catalyze the whole operation by igniting the mixture and bringing the engine to life. This entire system works flawlessly if the spark plugs are in perfect condition.   

However, when worn out due to carbon build-up or oil contamination, the spark plugs start to malfunction. They produce irregular sparks, and that intermittent pattern causes the pistons to move unnaturally. Sometimes, there is no spark, and you can feel like a missed heartbeat. If visualized on a graph, you would see it as a valley in an otherwise horizontally moving trendline. In automotive terms, we call it a misfire.   

Regular misfires are like jolting the engine back to life, which, as you can imagine, causes the engine to shake. Consequently, the more frequent the misfires, the more violent the shaking. Until it comes to a point where your whole car begins to wobble.      

Further Effects Of Bad Spark Plugs   

Engine misfiring and vibrations are not the only results of fouled spark plugs. Several other things can go wrong that we will discuss here.   

Engine Runs Too Rich  

Malfunctioning spark plugs do not properly ignite the air/fuel mixture, which in turn causes problems with fuel consumption. When the sparks are irregular, some part of the a/f mixture does not ignite at all, and it goes through to the exhaust unburned. In other words, you use fuel but produce no power.   

Sudden Loss Of Power   

There is no telling when a pair of faulty spark plugs will stop working. However, when it happens, you will immediately feel it is losing power. The throttle won’t work as effectively, your car will have problems accelerating properly, and the engine will sputter and stop.   

Pops And Bangs From The Exhaust  

When the engine runs rich, the fuel doesn’t burn within the combustion chamber. Instead, it ignites from the heat in the exhaust pipes, which creates exhaust backfires and the sound of pops and bangs.   

As soon as you hear something like this out of the blue, book an appointment with your trusted mechanic.     

Will Replacing Spark Plugs Help?   

It’s a no-brainer that replacing the old spark plugs with new ones will bring your car back on track. Every system malfunctioning because of bad plugs would come back to life. Overall, your driving quality would improve!   

But before you get to the changing part, you must ensure the spark plugs are the sole reason your car is shaking. You need to visit a professional mechanic for that and discuss your options. You will only have the full picture in front of you after a detailed analysis. Then, if the problem is indeed in the spark plugs, you’d have no choice but to replace the entire set.     

Other Reasons Your Car is Shaking  

Faulty spark plugs are only sometimes the root cause of vehicle vibration. There are several other reasons that your vehicle vibrates uncontrollably. Let’s look at other contributing factors that result in a shaking car.  

Beat-up Suspension System   

The suspension system takes the full brunt of vehicle vibrations that come through the road’s rough surface. As a result, suspension systems tend to wear out sooner than other vehicle components.   

When they fail to perform ideally, more surface vibrations are transferred to the car. Driving becomes uncomfortable, and you start hearing more strange noises from your vehicle.   

Worn Out Or Misaligned Tires   

The tires are the only thing connecting your car to the road. As such, you immediately feel the response when the tires go over a speed bump, a pothole, or a rough surface. But what if the road is fine, and your vehicle still trembles like crazy?  

It means your tires are out of commission and must be replaced immediately. Or the tires may be misaligned, causing excessive vibration at high speeds. You would have to inspect the tires to rule out each possibility closely.   

Faulty Brake Pads   

Brake pads can cause vibration only if they have uneven wear. And that only happens when the disc surface is rough.   

So, when you press the brakes on these uneven discs, the pads only encounter the peaks. This translates to vibration at high speeds, and it’s time to worry.   

Low Levels Of Transmission Fluid   

While listing the major sources of non-spark plug-related vehicle vibrations, let’s also talk about transmission hum.   

When the transmission fluid levels are dangerous, the gearbox makes noises. The constant hum is noticeable, even though it is not that loud. Then follows vibration and, ultimately, a warning light in your car’s dash.   

So, if the car shake worsens with each passing day, the gear oil may be the root cause.