After hearing your exhaust go pop, pop, and bang for the umpteenth time, you may wonder what is wrong with your engine.
The crackling, banging, and popping sounds you have heard may result from something happening in the engine.
But is this beneficial or harmful to your engine? Why do exhausts pop? Why does it happen when you change gears or perhaps when you let go of the throttle?
It can even become scary if you are experiencing it for the first time or if someone has complained to you that they saw flames coming out of your exhaust pipe.
Fortunately for you, we have done all the necessary research to help you determine if popping is harmful or beneficial to your car.
To understand everything we are about to explain below, let’s take a short refresher on how a car engine works.
How Car Engines Work: Quick Refresher
In fossil fuel-based cars, internal combustions power the vehicle and keep it moving. This happens in the internal combustion engine that uses a four-stroke cycle, intake, compression, combustion, and exhaust to keep your engine in motion and transfer this power to the wheels of your vehicle.
The intake stroke starts immediately after the intake valve opens to let fuel and air mixture into the engine cylinder. The piston then moves upward to compress the fuel and air mixture for the compression stroke.
Afterward, the compressed mixture is ignited by the sparkplug firing of the combustion stroke, which forcibly moves the piston downwards and rotates the camshaft. The exhaust valves open to let the exhaust gases out as the piston pushes upwards for the exhaust stroke.
All of this happens when you start your car engine and continues as you drive your vehicle. A mismatch of these strokes produces unfamiliar sounds that pop, crackle, or bang like gunshots.
Why Do Exhausts Pop, Crackle, and Bang?
A mismatch between strokes may delay or quicken combustion, causing the gases to combust outside the cylinder and the exhaust to pop, crackle, and make banging sounds.
A mismatch in the ignition stroke allows unburnt fuel to seep into the exhaust manifold or even lower down the exhaust. Hot exhaust ignites the fuel-air mixture, and the popping sound you hear is the mini-explosion that occurs when the mixture combusts.
If the ignition is slightly delayed, the combustion occurs somewhat in the cylinder and the exhaust, sending the excess of the mini-explosion sound into the exhaust and causing the crackling and banging noises.
The ignition can also occur too quickly when the intake valve is open, sending the sounds through it and the exhaust valve. A combination of this type that occurs entirely outside the cylinder can also send visible flames out through the exhaust.
But what causes this mismatch in the stroke cycles or a delay of the ignition?
Why Do Exhausts Pop: 5 Reasons To Consider
Insufficient Oxygen For Combustion
Combustion swiftly occurs when there is a perfect mix of fuel and air. If there is a lot of fuel, the excess will seep into the exhaust, combust and emit loud popping sounds. The same thing happens when the fuel is too little with excess air.
Both situations are not ideal for an internal combustion engine because they slow down ignitions. Combustion occurs when the exhaust valve is open, creating an escape route for the excess fuel mixture and repeatedly emitting pop and bang sounds.
Delayed Combustion From A Misfiring Spark Plug
Short-circuiting or carbon build-up can delay the ignition stroke causing the spark plug to misfire, which leads to combustion. The carbon buildup can also cause an engine shut-off after the popping and banging sounds pass.
Mismatch Of Strokes
In addition to the delayed combustion, a mismatch of strokes in the engine can cause several popping sounds or backfires. Any four strokes could be mismatched, leading to partial combustion or combustion outside the cylinder. Both will send combustible fuel through the exhaust manifold or up the intake valve.
If your car has vacuum leaks or air leaks in the exhaust system, an incorrect air-fuel ratio with less air will create a vacuum that sucks in atmospheric air, causing your exhaust to pop.
The function of a muffler is to contain most of the sound produced by the internal combustion engine. If you have a faulty muffler or you’ve had your muffler taken out, it could easily lead to popping and crackling sounds.
Is Exhaust Popping Bad? Can It Harm Your Car?
If you’ve been dealing with an engine that constantly makes popping sounds, you may have wondered if it is harmful to your car.
Depending on the vehicle, popping sounds can either harm or help the engine. Some cars like the Ford Focus RS and the BMW M4 incorporate pops and bangs into the system. Cars like the Hyundai Veloster N with turbochargers include an engine that includes pops and bangs as an anti-lag effect to prevent turbo lag.
As Engineering Explained host Jason Fenske showed, the pops and bangs are functional in such cars. When you shift gears, the mini-explosion in the exhaust creates pressure that keeps the turbocharger spooled up so you won’t lose your boost on the next gear.
In other vehicles, the pops and bangs may not serve any function apart from the sheer fun of loud sounds.
Depending on your vehicle’s configuration, popping can cause engine damage, destroy catalytic converters if they are present, or even reduce the horsepower of your engine, among other issues. Let’s look at how pops and bangs harm your vehicle.
5 Ways Popping and Bangs Harm Your Vehicle
They Decrease Fuel Efficiency
When you are driving, your car is constantly combusting gases. When you let your foot off the throttle, the vehicle should start idling and stop injecting fuel for combustion.
If the popping is still occurring after lifting your foot from the throttle to decelerate, this indicates that fuel is still being injected and combusted, ultimately reducing efficiency.
They Can Cause Engine Damage
Depending on the cause of popping, continual pops and bangs can damage some engine components after repeated combustions. The valves could be compromised, and excessive popping can damage seals. Pops and bangs can also damage the engine’s turbo, exhaust, etc.
They Can Destroy Your Catalytic Converter
If you are not running catless, exhaust pop and bangs will melt your catalytic converter, wearing it down over time and ultimately destroying it.
They Can Affect Engine Braking
Suppose your exhaust pop when you let your foot off the throttle; you can’t break immediately because combustions are still occurring. This could happen for a split second or two, but it’s worth noting if you are dealing with an exhaust pop or considering getting a tune.
They Can Reduce The Power Of Your Engine
Bad ignition timing can affect your performance and reduce your vehicle’s power for distributor-based ignition systems.
Is Exhaust Popping Beneficial? Can It Help Your Car?
Suppose your car is not configured to work with the pressure created when mini combustions occur in the exhaust. In that case, exhaust popping and banging will not help your vehicle, except to emit a machine gun sound on command.
If you recently started hearing your exhaust pop, this may be a sign of something wrong in your engine, like bad ignition timing that can affect your car’s performance or muffler and exhaust malfunctions. It would be best to get your vehicle inspected.
Although pops and bangs may not pose an immediate threat to the safety of your vehicle, they can cause damage over time if left unchecked and if your car is not configured for the occasional pop and bang.
How To Get Rid Of Exhaust Crackle?
If you hate the annoying sounds your exhaust is making, or you don’t want to take any chances on engine damage, you can adjust the tuning of your car to eliminate any extra combustion on deceleration.
Take your car to a professional tuning shop or your local mechanic for inspection. If there’s a vacuum leak or a faulty muffler system, a local mechanic can fix your exhaust and the muffler to stop the crackling and popping noises you find inconvenient.
You can adjust the distributor to correct the bad ignition timing on older vehicles.
The Electronic Control Unit can also be adjusted to cut fuel when you start decelerating on newer vehicles.
Frequently Asked Questions
How To Get Rid Of Exhaust Popping Sound?
The easiest way to reduce exhaust popping sounds is to take your car to a tuning shop and get it tuned. To do it yourself, you may have to install a Decat exhaust that increases the tendency of pops and uses mapping software to determine the frequency of pops.
Ultimately, what you are trying to do is manipulate the ignition timing of your vehicle so you can create pops whenever you accelerate or decelerate.
Is Exhaust Popping Bad?
While exhaust popping is not a functional feature on most cars, it is also not so bad.
Exhaust popping is due to unburnt fuel seeping into the exhaust manifold and combusting from the exhaust’s elevated temperature, causing mini explosions. If it’s not a functional feature on your car, it can slowly cause damage if it occurs frequently and if left unchecked.
Is Something Wrong With My Engine?
Exhaust pop could indicate lousy ignition timing, vacuum leaks in your car, and muffle problems. Your engine might need tuning and repairs to get rid of exhaust pop.
Why Do Exhausts Pop When I Accelerate?
When there is an inconsistency in the fuel to air mixture in your car, your exhaust may pop and bang when you accelerate. Combustion is delayed and occurs when the exhaust valve is open, causing a backfire that creates popping sounds.
The information we have shared here is straightforward and helpful for anyone looking for a detailed answer to “why do exhausts pop.”
The occurrence of exhaust popping should not cause an immediate scare because it does not undermine the safety of your vehicle in the first place. But If you are looking to put an end to it, now you know what to do and what to expect or whether you should be worried or not.