idling problem

Discussion in 'General Motoring' started by Sully, Dec 23, 2007.

  1. Sully

    Sully Guest

    I have a 2001 Saturn S series. Has 137,000 miles and has been very reliable.
    Lately it has had an idling problem.
    The idle varies from 800 to 2500 rpms. It changes all the time. It may start
    out high, or just change as I drive.
    I had it in for some work non related, I mentioned the problem, and they
    cleaned out the throttle body. It did not really help.
    Any ideas??

    Is he
    Or just blind--
    This guy who drives
    So close behind?
    Sully, Dec 23, 2007
  2. Sully

    Bob Shuman Guest


    Is the very high idle (>2000 RPM) usually when you re-start the vehicle
    after it was recently running and the engine is still warm? Have you
    noticed a reduction in mileage? Does the engine temperature gauge never go
    to where it used to when fully warmed? If any of this sounds familiar, then
    I'd suspect the Coolant Temperature Sensor (CTS).

    The CTS reports the engine coolant temperature and the computer enriches the
    mixture when it is cold. If it enriches the mixture when it is hot (but
    being reported as cold by the defective CTS), then it runs richer and idles

    The part costs about $10 at the local auto parts place and takes all of 5
    minutes to install yourself with minimal tools. If this does not fix it,
    then look for a vacuum leak. Good luck and post what you find for the
    benefit of others.

    Bob Shuman, Dec 23, 2007
  3. Sully

    S. Barker Guest

    Be examining the pcv line. I'll bet you find it collapsed and/or
    deteriorated to the point of having a hole in it.

    S. Barker, Dec 23, 2007
  4. Sully

    p_vouers Guest

    If it is idle high, 99% chance it is the CTS.. cheap and easy to
    change and the result will be instant. At $12 it's a no brainer. Just
    make sure the engine is cool and you open the collant overfill befor
    he swap. Swap fast enough and you won't lose any coolant or at least
    very little.
    p_vouers, Dec 24, 2007
  5. Sully

    oppie Guest

    PCV or EGR. Also possible for a TPS to be bad.
    Is the check engine light on? See if there are any codes stored and possibly
    have the OBDII data (not just codes) checked to see if anything looks out of
    whack. Some of the sensors are cheaper than paying for a diagnosis but
    sometimes you get lucky other times, the costs just add up throwing random
    parts at it.
    I like being able to look at the data stream. It tells you if the engine is
    running in closed loop (which it should be after it is warmed up and all is
    functioning within normal parameters). You can read the actual sensor values
    like the CTS and see if it is giving a believable temperature... Lots of
    information to be had with the correct tool. I borrow a Snap-On from a
    mechanic friend's shop.
    oppie, Dec 26, 2007
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