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Q: Car idles high and then low, and then becomes a 30 second cycle.

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My 2008 Dodge Ram 1500 has a 4.7 L engine. When i drive and i stop at a light or i am just at idle, my truck idles around between 750-1000 and after a while idle goes down between 600-750 and it just becomes a 15-30 second cycle. what could cause this?

My car has 130000 miles.
My car has an automatic transmission.

A: Hello. A few things I would check are the t...

Hello. A few things I would check are the throttle body, the idle air control valve, and the vacuum hoses. A dirty throttle body or idle air control valve can cause the idle to fluctuate. I would also examine the condition of all of the vacuum hoses, any cracked or leaking hoses can cause the idle to fluctuate as well. If you need assistance, a certified mobile mechanic from YourMechanic can inspect your vehicle’s idling issues at your home or office.

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