Audis are luxury cars that offer a little something for everyone. They are both sophisticated and yet practical and are designed for work as well as play. With classic design features and the latest innovations all wrapped up with quality German engineering, Audi is unlikely to ever let you down.
However, without proper maintenance, long-term use of any vehicle will start to show signs of wear and tear. With this in mind, in this article, we will look at some of the common reasons for Audi engine misfire.
The Ignition Cycle
Unless custom built, all modern engines operate upon a four-stroke (step) combustion system. These steps run in a continuous cycle while the vehicle is in operation and occurs as follows:
Stroke 1: Intake
The intake stroke involves the entry of air and fuel into the engine via the inlet valve.This is achieved through the pistons, cylinder, and crankshaft working together and is closely monitored by your Audi’s MAF sensor and OBD.
Stroke 2: Compression
The inlet valve then closes in a tight seal. The piston retracts backwards into the cylinder, which in turn increases the pressure within the chamber. This increases the flammability of the air/fuel mixture in preparation for ignition.
Stroke 3: Power
This is the stroke in which combustion occurs. The engines spark plugs fire, creating sparks which ignite the fuel. This sudden explosion of energy releases hot gas which is powerful enough force the piston to drop and power the crankshaft, resulting in forward motion of the vehicle.
Stroke 4: Exhaust
The outlet valve now opens and allows the exhaust gases which have been created by the burning fuel to exit the vehicle via the exhaust pipe.
Stroke 1, the Cycle Repeats
The process then begins again in perpetual motion, keeping the engine fed, and the crankshaft whirring, all the while the excess fumes are released from the exhaust pipe.
Why Misfires Occur
When the four-stroke process of an engine is interrupted, an engine misfire occurs. This can cause you car to either run poorly or fail to start. It is best avoided where possible to protect the overall health of your engine.
There are 3 different types of misfire:
- Lean Misfire: Where the air/fuel ratio is imbalanced and ignition becomes difficult.
- Ignition Misfire: Where ignition fails to occur, usually caused by the spark plugs.
- Mechanical Misfire: Where one of the many mechanical parts associated with the four-stroke process fail.
What Parts can Cause my Audi to Misfire?
As we’ve mentioned, your car is a complex series of parts that all need to work together to ensure a smooth motion. Therefore, if one of these necessary parts fail, it can cause a chain reaction resulting in misfire. Common part failures that can cause misfire include:
Fuel Injection System Failure
As the name suggests, the fuel injection system is in charge of supplying the engine with fuel. If the injectors of the system are clogged, they will not be able to provide the correct amount of fuel, resulting in a lean misfire.
A common fault that can occur with an Audi as it ages is the failure of the spark plug wiring. Spark plugs are essential parts of your car that should be regularly serviced and replaced as needed. When they fail, the air/fuel in your engine will not ignite, resulting in an ignition misfire.
Failure of the Crank Position Sensor
To ensure it is rotating at the correct speed, your Audi’s crankshaft has a sensor. This sensor is used to regulate the rotation of the crankshaft in response to changing factors such as speed. If this part fails, starting your Audi can become difficult and may result in mechanical misfire.
Seek Quality Servicing and Repair
If you’re an Audi driver frustrated by regular misfires, then look no further than European Motors Maryland. We will service your Audi if you live in or around Baltimore, Columbia, Ellicott City, or Catonsville, MD. European Motors Maryland will deliver quality service from a name you can trust. We are specialists in European imported vehicles. No job is too big or too small for our experienced team of expert mechanics. We are professionals in all we do. Our helpful team at European Motors Maryland will have your car back on the road quickly and free of misfires.