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Do Cars Still Backfire?

Do Cars Still Backfire?

Hearing your car sputter and cough can be one of the most painful sounds a car lover can hear. 

Backfiring could be a sign that something is wrong with your car, and that you need to get it checked before your car stops functioning completely.

But backfiring only happens in old cars, right? If you buy a new car, do you need to worry about backfiring?

Modern cars experience minimal backfiring due to their integrated systems that monitor and regulate fuel and air intake to the engine. The occurrence of backfires indicates that there is likely an issue with the vehicle’s tuning, timing, or spark plugs.

Although backfiring is uncommon in newer vehicles, it can still happen. Keep reading to learn more about the reasons for backfires.

Why do modern cars backfire less?

Fortunately, if you have a more recent car, then the chance of backfiring is very low. 

The reason is that older cars don’t have engines controlled by an integrated Central Processing Unit (CPU), which controls the engine and regulates the fuel intake by the engine. 

This makes backfiring rare, but not nonexistent!

Reasons Why A car Might Backfire.

If your car is backfiring, then there are several potential reasons for this. Let’s take a look at the most common!

Reason #1 The car hasn’t been properly tuned.

When a car isn’t properly tuned, the ratio of the fuel being supplied to the engine is unstable, and the engine starts receiving more fuel than it can burn.

When the engine has more fuel than it can combust, some of the fuel escapes into the exhaust, where it burns up upon exiting the exhaust. 

This is what causes the audible sound that either sounds like a gunshot, or “coughing.”

Coincidentally, this issue can occur if the engine isn’t getting enough fuel as well. When all of the fuel is not combusted at once, some will leak into the exhaust, where it will burn up upon leaving the exhaust.


A low supply of air means that the air filter is most probably clogged and dirty. Replacing the air filter is very easy, and inexpensive as well. 

Get it checked and replaced by a mechanic, and you’ll be able to remove this issue.

A low fuel supply could be due to a vacuum leak, clogged fuel injectors, or a broken fuel pump that is leaky and unable to pump enough fuel into the engine. 

Getting this looked at by a professional would be the best option for you.

Reason #2 Bad ignition timing

The ignition system within a car consists of two valves related to the intake of fuel and air and expel exhaust fumes. 

When the right amount of fuel and air enters the engine cylinder, the valves close and let combustion occur.

However, some fuel can leak into the exhaust and combust when this timing is off, causing the car to backfire.


This issue is more prevalent in older cars, and if this issue is occurring in a newer car that doesn’t have older parts like catalytic converters, then it may be cause for concern. 

Get this checked by a professional, and they might be able to solve this issue.

Reason #3 Faulty spark plugs

Older cars still use spark plugs and distributors, and faulty spark plugs can cause incomplete combustion of fuel within the combustion cylinder.

Newer cars have replaced the older spark plug system with the newer coil-on-plug systems, eliminating this issue. 

However, if your car is backfiring and has a newer ignition system, that may be a cause for concern!


Changing spark plugs in a car is very easy, and you can browse the net for your car’s model and check instructions online to change the spark plugs on your specific car.

However, replacing the newer coil system may be very difficult, and it is better that you have a professional mechanic take a look at this issue.

Reason #4 Carbon Tracking

Carbon tracking is usually found in older cars, and occurred when minute traces of carbon were collected within the distributor cap. 

After enough carbon was collected, it becomes enough to conduct electricity from one plug to the other.

This affects the power of the ignition spark, making it weak, leading to the fuel not being combusted completely, leading to the same issue we mentioned above.


This issue rarely occurs in newer cars, but you can use dielectric grease to prevent the spark plugs from tracking carbon for older cars.

We’ve attached a helpful and detailed guide, which you can view here. This guide gives easy to understand step-by-step instructions on dealing with faulty or carbon tracking spark plugs, along with the way to fix them.

However, we would advise that issues like these are best left to technicians who are able to understand the issue better.

Reason #5 Your car has a malfunctioning distributor cap

The job of the distributor cap is to send electrical pulses to the spark plug via wires. 

A broken distributor cap can affect the timing of the spark plugs igniting the fuel, which leads to fuel leaking into the exhaust.

Why do cars backfire when you start them?

Older cars often face this issue after a period of inactivity, since they require tuning every few months in order to be fully functional. 

Starting your car causes fuel to enter the combustion chamber, and all of the things mentioned above can play a part in the car backfiring.

The engine combustion timing might be off, the valves might be malfunctioning, or the distributor cap might be cracked. We’ve also outlined faulty spark plugs, and carbon tracking as factors that can cause backfiring.

Why do cars backfire when you turn them off?

When you turn off a car, the remaining fuel might escape out into the exhaust valve, causing it to combust on its way out of the exhaust valve.

Final thoughts

Aside from starting and shutting the car off, backfiring can occur while driving the car as well when you change gears, since fuel enters the engine combustion chamber when you shift gears, and it might continue entering the chamber after you’ve changed gears.

The best solution to deal with a backfiring car is to get it checked as soon as possible by an authorized and trusty mechanic, so you don’t make any mistakes fixing it yourself!

We hope this guide was helpful, and that you don’t hear that painful pop anytime soon!

Zach Reed

Hi, I'm the founder of! Having owned a wide variety of vehicles in my life, I was astounded at how hard it can be to find answers to common automotive questions. Rather than sit idly, I decided to create this website to help others!