A misfiring engine can be a mystery and a plague to drivers, no matter the make or model of their car. While some causes of misfires, such as spark plug deterioration, can be prevented by keeping on top of maintenance, sometimes, misfires just happen. In this article, we will learn why engine misfires happen and discuss the different types of engine misfire that your Audi may experience.
WHAT IS AN ENGINE MISFIRE?
On a basic level, your engine requires three things to run: fuel to ignite, oxygen to help burn the fuel, and a spark to ignite the mixture. If one of these elements is malfunctioning, then the engine will not be able to combust, meaning your Audi is going nowhere. This may seem simple enough to get your head around, but when you consider your engine is made up of a whole host of parts, and that any of these components could be to blame, discovering the root cause of misfires can become tricky.
While all vehicles may experience the occasional misfire in their lifespan, frequent misfiring should never be ignored. Misfires put extra strain on your engine, damaging connected parts and systems and negatively affecting your MPG and emissions levels.
If the air and fuel in the engine is not ignited, then your Audi has an ignition misfire. The spark-controlling parts of your engine system work very hard and can wear down fast. They will need to be replaced several times in your Audi’s overall lifespan. As spark plugs and the ignition coil begins to wear down, they will give a reduced electric output, which is what causes misfires which worsen overtime. This is one of the clearest signs of ignition misfires, as the rarely happen out of the blue and will instead worsen gradually. However, on the positive side, as these parts were intended to only have a limited lifespan, these parts are easy and affordable to have replaced.
Spark plugs are the easiest to replace along with ignition wires, taking only a few minutes. It is worth noting that if your Audi is a vintage model that has an old-school distributor, then the cap and rotor might need replacing, too. The most expensive cause of ignition misfire to repair are the coil packs, but even so, this is still affordable and relatively simple to complete.
For your engine to ignite fuel successfully, there needs to be a perfect balance of air and fuel in the engine. When this is off balance, the mixture becomes more difficult to ignite, leading to lean misfires. The parts involved with the fuel system typically last longer than those connected with the ignition system, but still can wear out over time. Often times, issues with these parts require servicing instead of replacements, such as replacing the fuel filter or cleaning the fuel injectors.
Another fuel-system issue that can occur is a stuck EGR valve, which will let exhaust gasses enter the intake manifold. This will result in the gasses settling where they should not be, which can interrupt the ignition cycle.
Unlike with ignition misfire, lean misfires tend to occur suddenly and can be noticed by the driver when idling but will be fine when driving at speed. An engine that sputters and struggles at an intersection but drives smoothly on the highway likely has a lean misfire issue.
Mechanical misfires are the least common and often most complex misfire problem and occur when any of the engines mechanical parts fail, such as the pistons or cylinders. This problem can also be caused by cracks in the vacuum lines, issues with the manifold gaskets, as well as the timing belt and valve train.
Mechanical misfires will affect your Audi at any speed and can quickly get worse. A bad mechanical misfire can cause severe engine damage, vibration in the cabin, as well as backfires.
AUTOBAHN AUTOMOTIVE SERVICE
Don’t let misfires ruin your Audi’s high performance and incredible driving experience. If you’re a resident of San Antonio or Longhorn, TX, or just passing through, make a pit stop at Autobahn Automotive Service. We are the experts in German-engineered vehicles and can get to the heart of your misfire issue quickly and affordably.