Replace your spark plugs when you notice:

• Rough idling or difficulty starting the engine
  
• Increased fuel consumption without explanation
  
• Poor acceleration or sluggish response
  
• Misfiring or unusual engine noises
  
  

For fleets, ignoring these signs can lead to reduced fuel efficiency, compliance issues during inspections, and unexpected downtime.

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Step 1: Gather and Check New Spark Plugs

• Make sure you have the correct spark plugs for your engine.
  
• Use a spark plug gap gauge to confirm the gap is correct before installation.

Step 2: Locate the Spark Plugs

• Open the hood and find the spark plug wires or ignition coils.
  
• Remove any engine cover if needed.
  

Step 3: Remove the Old Spark Plug

• Gently disconnect the ignition coil or spark plug wire.
  
• Use your socket wrench with extension to carefully unscrew the plug.
  
• Wipe the area clean with a rag.
  

Step 4: Install the New Spark Plug

• Thread the new plug in by hand first to avoid cross-threading.
  
• Use the torque wrench to tighten it to the recommended specification.

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Step 5: Reattach and Repeat

• Reconnect the ignition coil or spark plug wire.
  
• Repeat for all spark plugs, one at a time, until complete.
  

Step 6: Test the Engine

• Start the engine and listen for smooth idling.
• Check for improved response and performance.

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Pro Tip : For the best results, always replace all spark plugs at the same time to ensure consistent engine performance. Use a torque wrench during installation to avoid overtightening, which can cause damage. Before fitting, make sure the plugs are clean and free of grease

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• Overtightening spark plugs: can damage the cylinder head threads. Always follow torque specs.
• Skipping the gap check: even pre-gapped plugs can shift during shipping, causing misfires.
• ‍Mixing up plug wires: reconnecting them incorrectly leads to misfires. Replace one plug at a time.

• Keep a stock of the correct spark plugs for your fleet in your workshop.
  
• Log replacements in your fleet management software to track intervals.
  
• Combine spark plug checks with routine inspections to save downtime.
  
• Train drivers to report rough idling or misfiring early.