12 13... Spark-plug faults

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2006 BMW X5, 2006 BMW X3, 2005 BMW X5, 2005 BMW X3, and 2004 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.

Evaluation of sparking period at idling speed.

Normal ignition voltage peak Spark plug is OK.
Low ignition voltage peak Small electrode gap.
High ignition voltage peak Large electrode gap.

Fig 1: Evaluation Of Sparking Period At Idling Speed

Courtesy of BMW OF NORTH AMERICA, INC.

Evaluation of sparking period at idling speed.

Normal combustion period, spark plug is OK.

Fig 2: Evaluation Of Sparking Period - Normal Combustion Period

Courtesy of BMW OF NORTH AMERICA, INC.

Long combustion period, small electrode gap.

Fig 3: Long Combustion Period

Courtesy of BMW OF NORTH AMERICA, INC.

Short sparking period, large electrode gap.

Fig 4: Short Sparking Period

Courtesy of BMW OF NORTH AMERICA, INC.