Genuine BMW 2002 Spark Plug

BMW 2002 Spark Plug Parts Questions & Experts Answers

• Spark Plug
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  Q:

  What is the importance of spark plugs and Spark Plug Wires in the engine operation and efficiency on BMW 2002?

  Posted by Rushil P.

  A:

  The correct functioning of the spark plugs is essential for the engine's proper operation and efficiency. While specific plugs are recommended, it's wise to consult the plug manufacturer's guide when buying new ones, as specifications may change based on experience. Periodically, spark plugs should be removed for examination, cleaning, and potential replacement, especially if they've been used for 12,000 miles (19000 km) or their electrodes are significantly eroded. The plugs' appearance provides insights into the engine's condition: a clean and white insulator indicates a weak mixture or a hot plug, hard black deposits signify a rich mixture, an oily black appearance suggests engine wear, and light tan to greyish brown deposits indicate a proper mixture and a likely healthy engine. If there are long brown stains on the plug's exterior, it implies a faulty joint between the plug body and insulator, necessitating replacement. Sand blasting machines are effective in cleaning plugs and testing their condition under compression; plugs that don't spark at the recommended pressure should be replaced. The spark plug gap, crucial for optimal spark efficiency, should be set to 0.024 in (0.60mm). Use a feeler gauge to measure and adjust the gap by manipulating the outer electrode. Avoid bending the center electrode, as it might crack the insulation leading to plug failure. When reinstalling the plugs, use new washers and ensure the spark plug wires are in the correct firing order: 1, 3, 4, 2, with the first cylinder closest to the radiator. Lastly, regularly clean and wipe the spark plug wires, which typically don't need routine adjustments.

  Answered by BMW Parts Specialist Adrian / Jun 27, 2026