In addition to carbon buildup and oil leakage, black spark plugs can also be caused by overheating. If the engine is running too hot, it can cause the electrodes on the spark plugs to wear down and become coated in carbon deposits. This can lead to poor engine performance and reduced fuel efficiency. It is important to monitor the engine temperature and address any overheating issues promptly to prevent damage to the spark plugs.
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Oil seals keep contaminants separate from the lubricants that keep rotating shafts and precision bearings in good working order. Oil seals are also known as rotary shaft seals, lip seals, and shaft seals.