What is engine “kickback”? Why does an engine fail? These are some of the most common reasons.
Perhaps you’ve seen something similar. The exhaust pipe from the car in front emits “popping” sounds while you wait for the lights to turn on. The vehicle vibrates as smoke comes out of its exhaust pipe. It wobbles until a final explosion from the exhaust completes the scene. This scenario shows how backlash happens, but it’s not exactly accurate. The exhaust smoke indicates an inefficient engine. Vibration indicates that the engine is out of tune. This engine is known for kickback.
What causes kickback?
Kickback happens when the car’s fuel mixture and air burns outside of its engine cylinders. If this happens, it can cause engine damage and exhaust problems. If left unchecked, it can cause your engine to produce less power than it should and waste a lot more fuel. A car that is constantly backfiring is a sign of serious damage and urgent repair.
Kickback happens when the air-fuel mixture is ignited by spark plugs while the exhaust valves remain open. Most common causes of kickback are:
Poor working conditions vs. rich
A rich mixture is when there is more fuel being sent to the engine’s combustion chamber than it needs. There are many reasons that a rich mixture can occur, such as a leaky injector or dirty air filter. The exact ratio of fuel to air must be maintained for proper combustion. Too much fuel can slow down the combustion process and make it impossible to complete in one engine cycle. If the exhaust valves are open, combustion will continue and kickback may occur.
A lean engine can also cause kickback if it doesn’t have enough fuel. Lean mixture is a situation where the engine has less fuel and more air. A faulty fuel pump, clogged filter or clogged injector can all cause a lean mixture. Poor ignition can occur in vehicles with a lean mixture. Fuel that is not burned efficiently will not ignite and cause combustion to stop until the exhaust valves close. This can lead to kickback.
Modern computer-controlled cars use oxygen sensors to maintain the correct air-fuel mix. The air-fuel ratio can be incorrectly set if one of these sensors fails. In this case, an error code will be saved in the ECU’s memory and the engine fault lamp will light up to warn you.
Incorrect Engine Timing
Kickback is caused by delayed timing. A 4-stroke engine works on the principle of intake-compression-ignition-exhaust. This cycle is repeated on average 3,000 to 3,500 times per second in a moving gasoline vehicle. The spark plugs may ignite fuel if the ignition timing is incorrect. This can happen if the intake valves close or the exhaust valves are open. Kickback can happen if the air-fuel mixture does not get compressed and ignited correctly. Modern engines that are computer-controlled in timing are safer and less likely kickback.
Broken Distributor Cap
For vehicles without an ignition coil, a distributor is used to connect the spark plug wires and ignite the spark plugs. The distributor allows sparkplugs to spark and ignite fuel. The distributor cap can crack and allow moisture to get in, causing the spark plugs not to fire the correct cylinders.
Spark Plug Wires: Carbon Deposition
The distributor cap houses all spark plug wires. A short circuit can be caused by negative events that happen over time. This causes soot to build up on the spark plug wires. This can also happen with ignition coils. This is caused by a short circuit, and the spark from a spark plug is insufficient to ignite the fuel. The exhaust valves must be open to allow the fuel to ignite. Kickback can be caused by rapid combustion when the exhaust valves are open.
Kickback When Shifting
In some cases, kickbacks could occur during gear changing in vehicles that have manual transmissions. At high revs, fuel can continue to enter the cylinders if you press the clutch to shift gear. This fuel can build up in the exhaust, which can cause a popping sound when the clutch is released.
