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Q: My RPM needle keeps moving up and down

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Rpm needle keeps moving up and down

My car has 260000 miles.
My car has an automatic transmission.

A: Hello. This may be related to a faulty idle...

Hello. This may be related to a faulty idle air control valve. As you may know this is a unit that monitors the air intake into your car’s engine as it is mixed with fuel. When this is not functioning correctly, this will cause the car to idle very roughly as you describe or in some cases not at all. I would recommend having an expert from YourMechanic come to your home to diagnose the rough idle and replace the idle air control valve as necessary.

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