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Q: Why Does an Engine Idle Fast or Slow?

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Why does an engine idle fast or slow?

A: Several factors can cause a fast or slow en...

Several factors can cause a fast or slow engine idle. Running the air conditioning or defroster will speed up the idle speed of the engine. Components that impact the engine idle speed include the idle air control motor valve, air intake boot, and PCV valve or crankcase ventilation system. Monitoring the idling of the engine can prevent other issues and long-term damage.

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