What are the symptoms of worn o r faulty spark plugs in a Mercedes-Benz E-Class?

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What are the symptoms of worn o r faulty spark plugs in a Mercedes-Benz E-Class?

My Mercedes-Benz E-Class has been experiencing rough idling and occasional engine misfires. Could this be due to worn-out o r faulty spark plugs? What are the common symptoms of bad spark plugs in this model, and how can I identify if they need replacement?

Talha Kyanii asked on 11 Oct 2025 13:46:28 pm

1 Answer

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Gari Master - on 11 Oct 2025 13:47:33 pm

Worn o r faulty spark plugs are a common issue that can cause a range of performance problems in your E-Class. Common symptoms include:

Rough Idling: The engine may shake o r sound uneven when idling.

Engine Misfires: You may feel sudden jerks o r notice the engine stalling momentarily, especially during acceleration.

Difficulty Starting: The car may crank longer than usual o r struggle to start.

Loss of Power: Acceleration may feel sluggish, especially under load.

Check Engine Light: Faulty spark plugs can trigger misfire codes e.g., P0300 series.

What to Do:
Inspect o r replace the spark plugs if your car has crossed 40,000–60,000 km o r if you notice these symptoms. Use Mercedes-approved spark plugs often NGK o r Bosch for best performance.