Hi and thanks for using 2CarPros.com. If the engine idle is fluctuating, chances are you either have a vacuum leak or the idle air control valve (IAC) is not working properly.
Here are general directions for finding a vacuum leak:
https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge
Here are general directions for replacing an IAC:
https://www.2carpros.com/articles/how-to-replace-an-idle-speed-control-motor-iac
The IAC is located on the throttle body. I found a picture online so you can identify it. Picture two, item 4 is the throttle body on your engine.
I hope this helps you. Please keep in mind, a turbo can make a spooling sound. The information I provided is related to the engine speed changing.
I hope that is what you were looking for.
Let me know if you have other questions.
Take care,
Joe
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Saturday, May 26th, 2018 AT 9:12 PM