Driving With A Misfire: Everything You Need To Know

The cylinders of a vehicle engine are a fundamental part in the operation of this, driving with a misfiring cylinder will cause a poor performance of the engine, because in them are housed parts called pistons that fit completely to the walls of these through the use of piston rings, making there is no space where the compression can leak.

In these cavities enters a mixture of fuel and air to produce the explosions through the intake valves and gases are produced after the explosion that are released through the exhaust valves to the outside, thus producing the force of movement that the engine provides to the gearbox and transmission of the car.

driving with a misfiring cylinder

What causes a cylinder to fail?

In older engines, there may be several causes, the spark plug spark that generates the explosion in the cylinder is not sufficient, a jump in the current of the spark plug electrodes, deficiency in the fuel and air mixture that goes to the cylinder, lack of compression in the cylinder and obstruction in the exhaust system that prevents the correct exit of combustion gases.

Although the difference between engines more than 10 years old and those of today, in terms of operation is similar in some aspects, these factors can be more complex in engines less than 10 years old.

In the old ones for example, if there was no current jump or lack of spark in the spark plug, the failure could be due to malfunctions in coils, distribution cables, capacitors, and platinums, since the ignition was formed by an electrical environment that had ease to diagnose the problem and repair it.

Used sparkplug with a snot
Used sparkplug with a snot.

Current engines have neither condenser nor sinkers, so that the electrical environment is composed of a series of sensors such as electronic modules, crankshaft position, camshaft, power transistors and safety systems, these can cut at certain times the ignition, in addition to this any false electrical contact causes a faulty ignition operation, so it is more complex to determine the cause of a cylinder failure.

In the previous cases if tests have been made, and the results are a good spark plug spark, no current jumps, the fuel mixture is excellent, the parameter of the injectors is as required and the compression is above 90 lb /in, then the causes of cylinder failure may be:

  • Valve spring strength and elasticity has varied
  • Problems in the fuel regulator
  • Problems in the crankshaft position sensor

In more severe cases:

What happens when a cylinder fails?

Among the things that happen when a cylinder is failing is a loss of engine power, in a 4-cylinder engine will be losing 25 percent of the power it can produce.

The presence of constant irregular vibrations are another sign of the failure of a cylinder in the engine, the cylinders produce the explosions for the pistons to go up and down, and being subject through the connecting rods to the crankshaft, provide the force of movement to the car, a cylinder that is failing directly affects the fuel consumption of the vehicle, this is due to the work to be done by the cylinders that continue to operate to compensate for the power that is lost in the cylinder that is not working.

What happens when a cylinder fails?

An engine with a cylinder failure shakes when idling. If a cylinder failure is caused by clogged or dirty injectors and air leaks, the engine presents a general failure caused by a malfunction of all cylinders due to low pressure. A cylinder failure causes no power when accelerating the car, presents a strong smell of fuel at the exhaust outlet, and the smoke coming out of the exhaust is black, also the engine at minimum is unstable and shuts down very often.

One of the events produced by the failure of a cylinder is the difficulty to start the engine, it starts but fails to start, and if it starts, it happens some time after failed attempts to start it. usually a car with cylinder failure does not meet the conditions required by the laws of the countries in terms of pollution levels allowed.

In a cold climate, the failure of a cylinder is accentuated, and this also occurs when it is stressed with weight.

How long can you run a car with a failed cylinder?

Talking about possibilities like this can sometimes sound like ignorance, lack of knowledge, stubbornness and even irresponsibility, the truth is that neither in theory nor in practice car engines are designed for a halfway operation, if there is a failure of a cylinder simply the car can not be driven in that state, if there is the question of why?

There are many ways to answer it, the first is called instinct, you could ask the person who asks this question if he could walk or run with a fractured femur, the same happens with the car.

If a cylinder fails the engine is incomplete, it can not roll, if it is four cylinders, it is designed and manufactured so that the four cylinders to operate to generate the movement that the car provides.

Driving a car with a non-functioning cylinder exposes the driver to serious risks of danger, and not only the driver, but also the other occupants of the car. the passers-by. and the drivers and crew of other vehicles that circulate where a car with this failure is driving.

The second is an act of irresponsibility with oneself and a sign of ignorance of the car. since driving a car in this state implies causing serious damage to it. other fundamental parts of the engine will suffer significant damage, pistons, connecting rods, deformed valves, etc.

When you own and drive a car, you must have, besides the knowledge of how to start the car, the laws and the roads, a general knowledge about the operation of its essential parts, the main one being the car’s engine.

The third way is of an economic nature, since the cost of causing more damage to the car by driving it with a cylinder failure can be very high.

For all these reasons, there is only one answer to this question, you cannot and should not drive any kind of vehicle with a cylinder failure, the only thing to do is to get to a place where you can leave the vehicle or to a mechanic shop where the failure will be repaired.

How far can you drive in a misfiring Lexus LS400

Is it bad to drive with an ignition failure?

The most responsible, efficient, and safe way to drive a vehicle is that it is in optimal conditions to circulate, a vehicle with any mechanical or structural malfunction or deficiency, means taking unnecessary risks, which can endanger the life of the driver, crew and other people and drivers traveling on the roads.

It is also bad for the vehicle, if it is in a state in which the engine shuts down frequently, it can leave it stuck in places with high traffic, which would cause an additional problem to remove it from the road in such extreme conditions.

As if this were not enough, the fact that the engine shuts down, brings additional problems of great danger, since the power of the brakes is lost, and the hydraulic directions when the engine shuts down do not work, because the hydraulic pump of the cars works when the engine is on, increasing the danger by decreasing the ability to control the vehicle.

A car with defects in the ignition is not apt to circulate, if it remains accidentally on the road, it will run another additional risk, the transit authorities will tow your car to a state parking lot, which will represent that apart from the repair that you will have to do to be able to remove it, you will have to cancel the expenses of crane, parking, and the fine for circulating in a car that is not apt for it. and commonly a car in these places runs the risk that its carts are removed and do not guarantee the care to its structure.

Checking ignition and electrical system of a car

How to fix a cylinder misfire

In cases of misfiring of a cylinder, the first thing to do to fix it is to stop the vehicle, since the damage can increase, even a simple spark plug that is failing if not addressed in time can generate more serious problems, such as destroying a catalytic converter.

The first action to be taken is to identify which of the engine cylinders is the one that is not working properly, this is done by disconnecting separately each of the injectors, when disconnecting one of the cables of an injector it is observed that there is no variation in the operation of the engine, it means that this is the cylinder that is not working.

Next, it is necessary to verify that the cables are connected in correct form, a cable must be in perfect state of operation, or it will generate many problems, the measurements with polymeters are not enough, it is necessary to examine them physically, they can have breaks that derive the current to another place, if this happens with replacing the cable and verifying that the failure no longer exists, the problem will be solved.

Expert Tip: The masses should be checked, cleaning them properly, check the spark plugs, removing them and checking their color, and their condition, in case of any doubt there is no doubt they should be replaced.

Check the connectors of the injectors, look for corrosion and damages in the cable, verify the resistances placing the tips of a multimeter to the metallic connections of each injector, place the adjustment of the multimeter in 200 Ohms and compare the measures with those indicated in the catalog of your car. if the measures are not in agreement, replace the part

Verify the check the misfire persists, use for this purpose the automotive engine compression tester, if this measurement is less than 85 Ib/in there is a leak in that cylinder and in this case the assistance of a trained professional will be required, as there are probably problems in the valve train, cylinder head, piston rings and may even need a change of engine block if there is serious damage to the cylinders.

What is the cost of repairing a cylinder misfire?

The cost of repairing a cylinder misfire depends on the cause of the misfire, and could be between $10 and $100 if the cause is spark plugs, this depends on the number of cylinders in the engine, the model and make of the vehicle.

A mechanic holding old broken sparkplugs
A mechanic holding old broken sparkplugs.

If the causes are related to ignition components the costs are oscillating and could be between $240 and $360, the injectors, ignition coil and spark plugs are around $1200, a set of spark plug wires can range between $24 and $95 according to the make and model of the vehicle, the injectors are expensive parts that range between $1600 and $1800 and are also subject to the brand of the part, the vehicle and the number of cylinders in the engine.

Expert Tip: More serious causes, such as bad valves and engine block, easily exceed $2,000. not including ring and piston costs that can run into the thousands of dollars.

All these costs can vary depending on aspects such as the brand of the parts, the repair shop where the car is repaired and the number of cylinders of the car’s engine, and the capacity in cc. an 1100 engine will have engine parts with lower costs than an 1800 or a 2000 engine.

Can a cylinder misfire fix itself?

It is very difficult or rare that a case of this happens what could happen is that the cylinder failure occurs motivated to an excessive accumulation of carbon in a spark plug, and that by an explosion of those that occur in the cylinders this carbon managed to detach with this the failure would be eliminated.

But the normal thing is that any failure in the cylinder ignition, must be attended and repaired with urgency by people specialized in the mechanics and operation of engines, it must be this way to diminish to the maximum the risks of more damages in the engine, that would mean greater costs.


Driving with a failed cylinder not only affects the performance of an engine, but can cause more serious damage to the engine, and people, because a car with this type of failure should not circulate under any circumstances, diagnostics and revisions to the engines, should be consciously, periodically, and performed by experts in the mechanics of cars, to avoid unplanned disbursements of money, and ensure the proper functioning of the vehicle.

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About Brock Rangel

Hi, I am Brock, and I am the lead editor/photographer for TheCarColony. I have been a mechanic for over 14 years now, and I am here to spread my car knowledge across the web!