When you purchased your BMW, one thing that you likely weren’t expecting was for it to start running rough. That shaking feeling and annoying engine noise you experience as your vehicle idles is a nuisance. If it isn’t addressed soon, your BMW can develop into more serious symptoms over time. This article will address the issue of rough running, what causes it, and what can be done to fix it.
Causes of Rough Running and Rough Idling
Drivers may experience what is called “rough idling” because the shaking sensation is noticed most acutely when stopped at a red light or intersection. It is a common problem for drivers, especially those who drive older cars. Rough running and rough idling are the same thing, typically the result of an improper balance of air and fuel in the engine.
Rough idling is characterized by an unsteady rate of rotation, so you will see your BMW’s tachometer dance around different RPMs, rather than stay at a steady level. Thankfully, rough running can be fixed. But before we talk about how to fix rough running, we need to know what causes it
The Causes of Rough Running
There are quite a few causes of rough running, but some of the most common ones are listed below.
Dirty Fuel Injectors
BMW cars are very fuel efficient because their fuel injectors deliver the exact amount of fuel to the cylinders for each stroke. If the fuel injectors become clogged and dirty, they will not be able to deliver enough fuel to the cylinder, commonly resulting in rough idling as well as subpar performance and fuel efficiency.
Clogged Air Filter
Your car needs a liberal supply of air in order for the engine to run properly. If the air filter is dirty, air cannot reach the engine as easily, which can result in uneven performance and rough idling.
Spark Plugs in Poor Condition
The role of the spark plug is to deliver the electrical impulse needed to ignite the air and fuel mixture in the cylinders of your engine. Spark plugs will naturally deteriorate over time and become contaminated with dirt, oil, and ash, which reduces the magnitude of electrical impulse they can deliver. These circumstances can result in rough idling in your BMW.
Faulty PCV Valve
Positive crankcase ventilation valves, or PCV valves, handle leftover gases within the engine and have an effect on its air-fuel mixture. A leaky or blocked PCV valve can cause an air-fuel mixture that is either too lean or too rich.
Other Causes of Rough Running in Your BMW
The causes listed above are only the most common causes of rough running, but there are plenty of other scenarios that may cause that shaking feeling as you idle. A certified technician will be able to tell you what exactly is causing your problem in your BMW. A few other causes include an oxygen sensor that relays incorrect information, a head gasket leak, and fuel pump failure. If you are experiencing rough running in your luxury vehicle, it doesn’t have to stay that way.
How to Prevent Rough Running
Not only is rough running annoying, but the fact that it can easily be prevented makes it that much more frustrating. Regular maintenance and auto care, like regular air filter changes and frequent inspection of your BMW’s spark plugs, are the perfect cure for rough running, but these measures are mainly preventative.
A qualified mechanic will likely look to undo the damage that caused the problem. If none of the usual suspected causes are the culprit, they will check your BMW’s computer for warning codes as a firm diagnostic test.
DART Auto Will Help
Rough running can be caused by such a wide 
range of phenomena that it can be hard to pin down the exact cause. A trusted mechanic can be a driver’s best friend when experiencing a rough idle.
Look no further than the experienced mechanics at DART Auto in Denver, Colorado. We specialize in repairing high-end German automobiles. We have served residents of Englewood, Littleton, Centennial, and Denver and gained their confidence as the mechanic shop that truly puts the customer first. Our seasoned technicians make it their top priority to fix your car the first time, because we know how stressful car problems can be. Call us today to schedule your appointment.
