After starting a 2008 Suburu Tribeca (automatic), the engine idles at around 1600rpm. Even if I leave it for a few minutes, the revs don't change.

But, if I even slightly tap the accelerator, the revs drop from 1600rpm to around 900rpm (and stays there). This happens in both hot and cold whether, but it doesn't happen when the car is stopped at lights or in traffic; I've only noticed it when starting the car.

I've searched the internet but found no information on this. I also haven't seen this happen in any other car, so I doubt it's expected behaviour. 1600rpm when idling also seems unusually high.

What could be causing this to happen?.

1 Answer 1


This is the behavior on many cars - the electronic choke, operates below a certain temperature to give a smooth idle.

it is released as you start driving as well as the engine is warm. But blipping the throttle is another way of cancelling it which is what you are doing.

  • I think most EFI engines manage cold engine starting automatically, increasing cold engine idle then reducing rpm as the engine warms up without any input from the pedal. Perhaps a simple throttle body cleaning may help.
    – F Dryer
    Oct 16, 2021 at 9:52

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