What Would Cause Multiple Cylinder Misfire?

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What Would Cause Multiple Cylinder Misfire

Is your car losing power and producing some odd vibrations? Cylinder misfire could be the main culprit. Note that your car engine could have up to 16 cylinders depending on the type. Some car engines have a few up to two or four cylinders.

So, why is a cylinder necessary? Combustion takes place in the cylinder, thus powering your vehicle. If one cylinder misfires, there will be a loss of power. A misfire means that there is an absence/incomplete combustion. How do you know that your car has a cylinder misfire? Here are some signs to watch out for.

What Are Some Engine Misfire Symptoms?

1. Power Loss

The most obvious sign is power loss. Remember, combustion takes paces in a cylinder. If combustion is incomplete, your car will become sluggish.

2. High Fuel Consumption

How often do you refill your tank? If you refill more frequently than usual, there could be a cylinder misfire.

3. Sound

When your engine misfires, your car will start producing an irritating sneezing/coughing sound. Apart from irritating you, it will annoy other motorists as well. So if you hear such a sound, have the mechanic fix the problem at once. It will also produce excess vibration when it’s idling.

4. Odor

Driving a vehicle that is producing an odor can be annoying. Once incomplete combustion occurs, and the fuel fails to ignite correctly, the car will produce some awful smell.


Your car should accelerate with ease whenever you command it to do so. Unfortunately, with a cylinder misfire, it will fail to respond quickly due to loss of power.

The Dangers of a Misfiring Cylinder

How long can I drive with a misfiring cylinder? First, you have to understand the risk involved. Maybe your car has four cylinders. If one misfire, it means that 25% of the power will get lost. In order to compensate for the loss, the other cylinders get overworked. Imagine speeding on a busy highway only for the other cylinders to misfire? You could get in a nasty accident. Since the multiple cylinder misfire can be dangerous to you and other motorists, avoid driving the car with a misfired cylinder.

The idea of going to the mechanic and paying some cash is not impressive. But failure to fix the problem in time may accelerate and damage your engine. That will cost you a higher cost of repairing or replacing the engine.

Causes of Cylinder Four Misfire

Among the different cylinders in your car engine includes cylinder 4. Just like the other cylinders, it can misfire as well. The main question remains, what causes cylinder 4 to misfire and how to fix it? For new car owners, it can be difficult to diagnose your vehicle’s problem. Thanks to technology, you don’t have to be a mechanic to know that there is a misfire in cylinder 4. Once the misfire occurs, the vehicle error code system will show the PO304 problem.

Some of the leading causes include fuel delivery problems, ignition system issues, and engine mechanical problems. Below are some signs to show that cylinder 4 has a problem?

Signs of a Problem In Cylinder 4

  • Power loss in the engine
  • A rough and shaking engine
  • The exhaust will produce an odor
  • Whenever you accelerate your car, it will start to jerk.

Can You Still Drive With A Cylinder 4 Misfire?

Immediately you see these signs; you need to visit or call the mechanic right away. Failure to fix the problem urgently will result in ignition failure and also catalytic converter damage. Driving such a car puts you and other motorists in danger.

Diagnosing Code P0304

1.  You don’t want to risk treating one problem and dealing with another one later. That’s why you require ensuring that there is no other available code error. You can achieve that by scanning your vehicle using FIXD.

2. Among the causes of misfire include loose connectors in your ignition coil. Tighten any loose connector.

3. Worn out and faulty spark plugs are another cause of cylinder misfiring. Inspect the spa and replace them if need be.

4. Low fuel pressure is among the causes of the engine misfire. You need to check if your ignition system is functioning well. In most cases, the clogged/faulty fuel injector can cause low pressure. So check the fuel injector’s condition and replace it if needed.

What Causes a Cylinder 3 Misfire and How to Fix

If your car has a cylinder 3 misfire, you will get an error code p0303. Deal with the problem immediately since delay may cause engine damage. To verify that cylinder 3 is the one having misfires, check the following symptoms;

The exhaust will produce a fuel smell, power loss, rough engine, and check engine flashlights. Again, if you accelerate, the car will jerk

Causes of Cylinder 3 Misfire

1. There are several causes of cylinder 3 misfires. They include defective spark plugs, the spark plug wires, and coils: faulty fuel injector, vacuum leak, low-quality gas, and low pressure, among other causes.

2. A loose or damaged ignition coil can cause an engine misfire. Check for any fault and replace them if needed.

3. Check the spark plug and their wires. Test if they are okay. If they are defective, you need to replace them right away.

4. If the misfire is still occurring, check the fuel system. Since low pressure causes misfire, the problem could either be in the fuel pump or even the fuel pressure regulator.

How To Fix It

To fix the misfire, you need first to diagnose the problem. To ensure that P0303 is the main problem, scan your car using FIXD. In case there are other engine misfires, you will see the codes.

Cost of Fixing Cylinder 3 Misfire

Your mechanic will have to diagnose the problem first before fixing it. If the problem is the spark plug, the total cost of repairing/ replacing it will range from 40 dollars to -640 dollars. If the fuel injector is the problem, labor cost plus repair may cost you an average of 1500-1900 dollars. Unlike the fuel injector, repairing the vacuum seal is cheaper with a range of 100-200 dollars. Repairing a fuel pump can be expensive, too, with a cost ranging between 1300-1700 dollars. The price will vary depending on the severity of the damage and the type of the component.

Dangers of Driving A Car With Cylinder 3 Misfire

Other than posing a risk to you and other motorists, you may end up damaging vital components. Such components include the catalytic converter as well as ignition failure. To avoid worsening the situation, visit your mechanic immediately; you get p0303.

What Could Cause A P0304 Code?

As indicated above, once the system shows code error p0304, it means that cylinder 4 has a misfire. It’s a problem that you need to address since it can result in engine damage. To be sure that cylinder 4 is the one that has misfired; you need to be sure that there is no other code error. How do you diagnose the code error?

Main Causes Of A P0304 Code

1. Bad Spark Plug

If your spark plugs are either faulty or have worn out, you need to replace them. If your car is old, you are likely to experience this problem. Luckily, the spark plugs are cheap, and you can replace them quickly. Other than the engine misfire, there are several signs of a bad spark plug. They include, check engine lights, rough idle, poor fuel economy, not to mention rough acceleration and difficulty in starting the car

2. A Faulty Ignition Coil

A bad ignition coil is another cause of the misfire. You need to inspect it and if it’s faulty or damaged, replace it immediately.

3. Leaking Head Gasket

If your car is an old model that lacks a steel gasket for intake, you will likely experience this problem. That doesn’t mean that a modern car cannot experience this problem. To avoid dealing with such problems in the future, inspect the intake manifold gasket for any leaks. You should also check if there are broken vacuum hoses.

4. Low Fuel Pressure

If the pressure is below the manufacturer’s specified level, it will cause a misfire due to the lean mixture. You can avoid that problem by inspecting if the pressure fuel regulator is faulty. If it is okay and pressure is low, then the fuel pump could be defective, or the fuel filter could be clogged.

5. Faulty Fuel Injector

A faulty fuel injector is a common problem with old cars. Unfortunately, it’s not easy to detect. To be certain, you need to flow test it. If you don’t repair/replace the fuel injector, misfiring will occur.

6. Low Engine Compression 

Have you imagined that the inner part of your engine could be damaged? If that’s not the case, the problem could be a result of low compression. Among the causes of low compression includes a faulty timing belt. That means you need to inspect it and repair it.

7. Vacuum Leak

Vacuum leaks cause a lean fuel mixture. It becomes a challenge to ignite, thus causing a misfire.

8. Camshaft Sensor Defective

The work of an engine control module is to regulate the fuel that enters the combustion chambers. It’s also responsible for ignition timing to ignite the fuel. To do all this work, requires getting data from the camshaft sensor. Timely ignition increases your engine power and also fuel economy. It also reduces tailpipe emissions. Once the camshaft sensor becomes defective, the engine control module will not get data in time, causing a misfire. The car will have no power to start.

9. Crankshaft Sensor Defective

A crankshaft is a vital monitoring component in the engine. It gives the engine control unit information about the speed and position of the crankshaft. If it becomes defective, the engine will overheat, and there will be Circuitry Problems. Failure to provide the right information will cause a misfire.

10. Poor Quality Fuel

Some people want to make a profit and end up contaminating the fuel. Some sellers eliminate dispersant-detergent additives from their fuel to make more profit. You might also buy fuel that contains water, alcohol, among other elements. As a result, your car cylinder up misfiring and show error P0304.

Other causes include distributor failure and engine time off.

Cost of Fixing P0300

Random misfire results in the code P0300. Once you get this error code, get the mechanic to repair the car immediately. Don’t ignore the problem and drive in such a state. You will damage the engine or even the catalytic converter. As a result, you will incur a high replacement/repair cost.

How much does it cost to fix p0300? Once you notice the problem and visit the mechanic, plan to spend between 250-900 dollars. The cost will vary depending on the damaged parts that require replacement. If you need a diagnostic check alone, the mechanic may charge you 100 dollars.

Main Causes of P0305

If there is a misfire in cylinder 5, the power train control module will trigger your check engine light on. You will receive a notification of code error p0305. It’s a common problem, and when it occurs, you will get the following symptoms.

Symptoms of p0305

  • Power loss
  • Rough ride
  • High fuel consumption
  • The check engine light will turn on
  • Tough time starting the car
  • Rough time accelerating

Just like the other cylinder misfire above, you should not continue driving the vehicle at that state. The mechanic should check and fix it. You need to know the causes to help you avoid a repeat of the same.

Causes of Cylinder 5 Misfire

  • Issues with the ignition system
  • Defective camshaft sensor /crankshaft sensor
  • Wrong throttle position and faulty computer system
  • Exhaust gas recirculation
  • Evaporation emission system problems

Dangers of Driving A Car With Cylinder 5 Misfire

If you fail to immediately fix the problem, you will put yourself plus other motorists and passengers in danger. Again, the catalytic converter will get damaged, and there will be an ignition failure.

Diagnoses and Repair of P0305

  1. Start by scanning your car using FIXD to check if there is an existence of other error codes.
  2. Ignition coil and damaged wires can result in cylinder 5 misfire. Check the wires and tighten the loose ones.
  3. Check the ignition system and the fuel system. If the engine lacks enough fuel, let the mechanic take a look.
  4. Defective spark plugs and also spark plug wires are other causes of the misfire. Check them and replace the faulty spark plugs.
  5. Low pressure can also cause a misfire. Check the fuel pump and the low-pressure regulator to ensure that there is the right pressure.

Before an engine misfires, numerous warning signs appear. You have to be keen enough and take necessary measures where necessary. For instance, if you get error code p0171, it indicates that the system is too lean. In several misfires, you may get other codes such as p0301, p0302, p0303, and so on.


You need to check the cylinder’s misfiring symptoms and take immediate action. Among them include loss of power in the engine, car jerking when accelerating the car, and odor. If you see these symptoms, the chances are high that there is a cylinder misfire. You need to diagnose the problem and fix it immediately. If you can’t, you should call your mechanic to take a look and repair your car. Failure to do so, you may end up incurring a higher cost of repairing an engine or a catalytic converter. You need to know different error codes that appear in the system in case of a misfire. The cost of fixing your car will vary depending on the extent of the damage.

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