Fixing Audi Engine Misfires in Decatur
Audi represents some of the best automobile engineering to come from Germany. With understated efficiency and performance in abundance, Audi vehicles are perfectly crafted to handle the rigours of modern life. However, time and use can take their toll on your car, and if you have not been keeping up to date with servicing and maintenance, parts can begin to fail and your Audi can display worrying symptoms.
One such symptom that can be both frustrating and worrisome for drivers is frequent engine misfire. Regular misfiring and stalling can wreak havoc on an engine. With this in mind, in this article, we will look at how you can solve the mystery of why your Audi is misfiring through understanding the combustion cycle and common causes of misfires.
The Combustion Cycle
The combustion cycle is the same across all engines, unless they are specially designed to function otherwise. All modern consumer car engines use what is known as a four-stroke combustion cycle, which constantly repeats while you drive:
1. Intake
In the intake stroke, air and fuel enters the engine through the inlet valve. This is made possible by the piston, cylinder, and crankshaft working together.
2. Compression
In the compression stroke, the inlet valve closes which forms a tight seal allowing pressure to build. The piston increases this pressure by retracting into the cylinder. This high-pressure environment is perfect for igniting fuel.
3. Power
The power stroke is when everything happens. The spark plugs create sparks and ignite the air/fuel mixture. This combustion releases an explosive amount of energy, creating a surge of hot gas which forces the piston to drop from the cylinder. This allows the built up energy to be released so it can power the crankshaft, thus engaging drive.
4. Exhaust
In the exhaust stroke, the outlet valve opens and the exhaust gases are able to exit the car through the catalytic converter and the exhaust pipe.
This four-stroke process repeats over and over while you are driving, keeping the engine fed and driving the crankshaft. However, if at any stage this process is interrupted, then what is known as misfire occurs. There are three different kinds of misfire:
- Lean Misfire: Where the air to fuel ratio is incorrect
- Ignition Misfire: Where parts such as the spark plugs fail to ignite the fuel
- Mechanical Misfire: Where a mechanical part fails, such as the pistons
What causes misfire?
As the combustion cycle involves so many of your engine’s systems and associated parts, there can be many reasons as to why misfires occur. Listed below are some of the most common causes.
Fuel Injector Faults
The fuel injector nozzles need regular maintenance to ensure they don’t become clogged with debris from fuel. If they become clogged, misfires can occur because the blockage will prevent the correct amount of fuel entering the engine, resulting in lean misfire.
Spark Plug Problems
Your Audi’s spark plugs will need replacing multiple times within the lifespan of your vehicle, as they are hard working parts that can become burned out. If the spark plugs are on the fritz, then the sparks they create will be intermittent or inconsistent, leading to poor ignition of fuel and ignition misfire. The spark plugs may also create power surges, which can damage related systems, such as the ignition coil.
Crankshaft Failure
Your crankshaft needs to turn successfully as part of the combustion cycle. To help make this happen, your crankshaft has a position sensor. This informs your vehicle’s onboard computer of the position and RPM of the crank, which allows it to properly regulate associated systems. If this part fails, then mechanical misfires will occur, and your Audi may fail to start even after several tries.
How We Can Help
At Munich West of Decatur and Atlanta, GA, 
we believe in customer satisfaction above all things. Because of this, we are dedicated to ensuring that when your Audi leaves our shop, it is in perfect running order. We have over 33 years of experience repairing European cars, and in that time we’ve seen it all. We are so sure of our ability to fix your car that we have a 2-years/24,000 mile standard guarantee. So if your Audi is regularly misfiring, please contact us today for an appointment or stop in for a consultation.
