Rough running, also known as rough idling may happen when you are an intersection or at a red light and your BMW’s engine makes sounds, becomes shuddery, or will then have slow acceleration when attempting to accelerate. It is a common misconception that this is simply a symptom of an aging vehicle and should be seen as nothing more than a minor annoyance.
However, this is simply not the case.
Rough running is entirely preventable and should always be remedied where possible to prevent more extreme symptoms from occurring. Remember, when you bought your BMW, you chose a luxury car. You invested your money in a car known for its peak performance and amazing driving experience. So why settle for anything less?
Symptoms of Rough Running
There are a variety of different symptoms which can contribute to the running of your BMW being described as rough. Listed below are some of the most common symptoms you should be aware of:
1. Rough Acceleration
A luxury car like a BMW should always accelerate smoothly and tightly without any type of struggle. However, when parts of your BMW have failed or are poorly cared for, your BMW will feel like it has lost its power; that is to say that acceleration feels slow and forced.
2. Poor Fuel Economy
Also known as poor mileage or poor fuel efficiency, poor fuel economy is where your BMW guzzles fuel, causing you to frequent the gas pumps far more often than normal, leaving your wallet depleted.
3. Misfiring
Misfiring occurs when combustion within your engine fails, which can be caused by mechanical failure (mechanical misfire), failure to ignite the fuel (ignition misfire), or a poor air/fuel mixture (lean misfire).
4. Check Engine Light
As rough running most commonly results in faults in the engine computer, your BMW’s check engine light may illuminate. This light is found on your dashboard. If you discover this light illuminated, it is best to take your car to a professional such as EGA as soon as possible.
Causes of Rough Running
As you have probably guessed, different symptoms of rough running tend to have different causes, and listed below are some of the most common.
1. Spark Plugs/Ignition Coils
The job of a spark plug is to ignite the air/fuel mixture within the engine by making a spark. If these parts are old or failing, they may struggle to produce a spark, resulting in ignition misfire and a rough running engine.
2. Fuel Injector
Fuel injectors are responsible for adding fuel to the combustion chamber of the engine. If these fail or become clogged, it will affect the air/fuel ratio of your engine, leading to lean misfire.
3. MAF Sensor
The mass air flow sensor is responsible to monitoring the amount of air that enters the combustion chamber of your engine. If this part fails, the BMW’s onboard computer is left to guess how much fuel to add in response, which can also lead to lean misfire as well as increased fuel consumption.
4. Tires
This is one of the few issues of rough running which does not have to do with the engine. As your tires are the part of your car which actually touches the ground, if they are poorly maintained, you may not only be left with a vehicle that feels every bump in the road, but it also may struggle to accelerate or perform properly due to lack of grip. Factors such as low tire pressure, worn out tire treads, misaligned wheels, and wheels which are unbalanced can all leave your BMW with a rough running sensation.
Ensuring Smooth Operation
Remember, no luxury vehicle ever needs to run roughly. If you notice your BMW begin to show any of the signs or symptoms above, it is important 
to seek repairs as soon as possible. Responding quickly to potential problems will reduce the potential impacts on your BMW, your time, and your wallet.
If you drive a BMW, Audi, Mercedes-Benz, MINI, Porsche, Sprinter, or Volkswagen and live in or around Escondido, Rancho Bernardo, Valley Center, CA, and are worried about the rough running of your vehicle, then visit Escondido German Auto. With five-star reviews and 20 years of experience, we know exactly what it takes to have your car driving as smoothly as when it left the factory floor.