Bob Workman’s European Automotive 

In almost all cases, a sputtering engine is trying to tell you that there is a deeper problem that requires immediate attention. An engine running out of gas will definitely sputter but if the gas gauge indicates full, the problem lies deeper inside the engine compartment.

An incomplete combustion in the engine will cause a sputter as can the
ignition system. The fuel system, such as a blocked fuel injector may also
cause the vehicle to sputter. While a sputtering engine may not seem like a
major issue, it is a symptom of a bigger problem that will not self-correct and
will eventually result in a much more expensive repair. The source of the
sputter should be investigated and repaired as soon as possible.

Common reasons for this to happen:

  • Worn Seals or Gaskets: There are several gaskets and seals in the exhaust system and if any of them are failing it can create a rough or sputtering engine. Gaskets and seals wear down over time and will eventually have to be replaced. Failing to do this in a timely manner can damage the exhaust manifold which is a much more expensive repair.
  • Malfunctioning Oxygen Sensors: Oxygen sensors measure how rich or lean the exhaust gases are when they leave the vehicles combustion chamber. The vehicle computer uses this information to adjust the amount of fuel entering the engine. A dirty or failing sensor puts too much or too little fuel into the engine causing it to run rough or sputter. Oxygen sensors must be replaced on a regular basis.
  • Dirty Fuel Injectors: Fuel injectors spray fuel into the cylinders. It is then mixed with air and ignited. Fuel injector nozzles can become clogged over time, which can lead to a sputtering engine, slow acceleration and the car not having enough power. Fuel injectors can be cleaned if the problem is caught early, but as the conditions worsens, the injectors may have to be replaced.
  • Bad or Dirty Spark Plugs: Spark plugs are responsible for igniting the fuel in the combustion chamber. If they are not working correctly or are dirty they don’t ignite the fuel cleanly and the car can misfire or sputter. The plugs will need to be replaced or cleaned.
  • Dirty Mass Airflow Sensor: The mass airflow sensor measures the amount of air that is entering the fuel injection system. It sends that information to the vehicle computer, which then delivers the proper amount of fuel to the combustion chamber. A dirty mass airflow sensor will send the wrong information to the computer resulting in a rough running or sputtering engine.

If you’ve noticed that your
BMW sputters when it is starting up, then it is time to schedule an appointment
with us at
Bob Workmans European. Give us a call today!