2008 Subaru Forester Revving With Clutch In

fsbfsb Member Posts: 9
edited July 2014 in Subaru
The idle of my 2008 Forester oscillates (between 1000 and 2000 RPM) indefinitely when I push in the clutch with the transmission still in gear. As soon as I take the car out of gear, the idle drops back to normal. I took the car to the dealership who was able to reproduce the problem but, because they didn't have a fix for it, their answer was that the car is behaving as designed. The service advisor more simply described it as a design flaw. I wonder if anyone else has the same problem and if they've had better luck getting it resolved.


  • ateixeiraateixeira Member Posts: 72,587
    I doubt they're all like that, though I have not driven a 2008 specifically.

    Call 800-SUBARU3 and open up a case. They can help your dealer get to the bottom of this.

    The ECU sets the idle speed, so I bet one of the inputs is malfunctioning - a sensor or something.
  • kurtamaxxxguykurtamaxxxguy Member Posts: 1,798
    The XT I drive does not have this oscillation. A/C on will raise idle slightly.
    As Ateixeria mentioned, could be bad sensor or faulty ECU.
    If dealer gives no satisfaction and no other dealers are available, try opening case with Subaru.
  • epgolfsepgolfs Member Posts: 16
    Tried duplicating this on each of the 3 Foresters I've got sitting in my lot & couldn't. I wonder, though: You've got "Incline Assist" with a manual ~ it does not specifically STATE it in any of my documentation, but I wonder if in addition to applying the brakes momentarily, it also raises the engine rpm if the clutch is depressed on an incline....ARE you on an incline while this happens?
  • p0926p0926 Member Posts: 4,423
    I can't see the hill-holder feature having any effect on the idle speed, it's merely keeping the brakes applied for you.

    There's definitely something not working right though, the idle on a warm engine should hold steady at 750 rpm, regardless of whether it's in gear or not.

  • fsbfsb Member Posts: 9
    Thanks for your reply ateixeira,

    The dealership mechanic who worked on the problem, having exausted everything he could think of, did open a case with Subaru. But they weren't able to help him.
  • fsbfsb Member Posts: 9
    I don't know if it matters, but my Forester is a PZEV (Partial Zero Emission Vehicle).

    The problem can be duplicated at will and occurs any time I push in the clutch while I'm in motion in any gear, incline, or speed, with or without air conditioning.

    Strange eh?
  • aathertonaatherton Member Posts: 617
    My 08 Forester does not have this flaw. But it's a non-PZEV automatic.
  • ateixeiraateixeira Member Posts: 72,587
    We did get a PZEV, but the idle is smooth. Just got it last night so I'll pay close attention to how it idles tonight.
  • paisanpaisan Member Posts: 21,181
    Get your ecu re-flashed. I had messed with an ECU modifying program on my 05 LGT and the same thing happened. I reflashed the ecu and it fixed it up for me.

  • johnvjohnv Member Posts: 40
    I think I've seen the same thing in my 2008. Does it stop when the car comes to a complete stop? I see this when I'm coasting in gear, clutch in towards a stop sign. Stops as soon as I stop rolling.
  • fsbfsb Member Posts: 9
    Yes, it does. It sounds like the same problem. Is your Forester, by any chance, a PZEV?
  • fsbfsb Member Posts: 9
    Thanks for your reply, ateixeira. The dealer wouldn't do it because they said that my car already has the latest version already. I'll have to go back and insist that they re-flash it.
  • ateixeiraateixeira Member Posts: 72,587
    You can still reset the ECU by disconnecting the battery. Disconnect the negative, wait 20 minutes, reconnect.

    Have your keyless remote ready and lock and unlock a few cycles to reset the alarm.
  • fsbfsb Member Posts: 9
    Excellent! I'll try it. Thanks very much!
  • paisanpaisan Member Posts: 21,181
    I'm not sure that will work though Juice. I think he'll need it to be re-programmed as there is definitely a problem in programing.

  • fsbfsb Member Posts: 9
    Hi ateixeira, I reset the ECU (by disconnecting the battery for 20+ minutes) and got some interesting results. For the first 20 minutes (in surface streets driving), the idle (albeit a bit unstable*) did not bounce between 1000 to 2000 RPM when coasting in gear. However, after that (in freeway driving) the problem came back and is now behaving consistently as before.

    *By unstable, I mean that, when coasting in gear, the idle would settle to around 1000 RPM until I took the car out of gear, at which time it would return to normal (about 850 RPM). Same problem but less pronounced.

  • johnvjohnv Member Posts: 40
    Yup, 2008 PZEV. I was able to confirm that the revving only happens when I'm in gear (usually 3rd for coasting) with clutch in. Shifting into neutral dropped the rpms to idle.
  • fsbfsb Member Posts: 9
    Did you take it into your dealership? If so, what did they say?
  • johnvjohnv Member Posts: 40
    I haven't yet but I'm due for my first oil change so I guess I'll dealer it and ask about the revving too. Have you seen people post about this on any other boards? (It's great to know that I'm not crazy ;)
  • fsbfsb Member Posts: 9
    I haven't seen anyone else post about this problem. I've posted in other boards as well but, so far, you're the only 2008 5-Speed PZEV owner who has replied (with or without the problem).
  • johnvjohnv Member Posts: 40
    a TSB was issued that probably fixes this issue. I haven't taken my forester in for this fix as yet.

    #11-89-08 Reprogramming Files For High Idle When Clutch is Disengaged

    Also on a different board, someone reported a similar issue that turned out to be the accelerator pedal position sensor (in an 05 model).
  • leadhead1leadhead1 Member Posts: 4
    Hi there

    I drive a 2008 black subaru forester manual base model.

    My car did the exact same thing all time and i asked the dealer what was going on.
    They were unsure at first and told me that they would contact subaru and get to the bottom of it.

    I recieved a phone call three days later saying that there was a Re-flash available
    I drove in the next day had the re-flash done and all was well.

    I read the report about disconnecting the battery on here and then the problem came back

    i found out that:


    Good work and thanks for the advice
  • paisanpaisan Member Posts: 21,181
    Disconnecting after a reflash does not wash out the reflash unless the dealer did not install it correctly.

    Subaru Guru and Track Instructor
  • leadhead1leadhead1 Member Posts: 4
    You will have to understand the system that there are two random access memories. One is for lets say there was a recall and or an emmision concern and the memory had to be re-learnt. The re-flash for this concern is not permanent fix and disconnecting the battery will erase it. I watched the dealer carry out this re-learn and its fool proof that i think that you could even do it.

    I phone the technical department for subaru and they even confirmed that this is the case.
  • leadhead1leadhead1 Member Posts: 4
    This is an australian built which has different design capabilities for mapping the ECU please confirm your region before advising so called fixes
  • paisanpaisan Member Posts: 21,181
    Sorry, I am basing this on USDM spec cars. It would be kind of dumb for the ECU not to keep all the updates to the memory for things like recalls and such when you changed the battery. That would be a major liability for the manufacturers! Hence why when they do flashes like that here in the US they are more or less permanent even if you change the battery.

    Subaru Guru and Track Instructor
  • johnvjohnv Member Posts: 40
    At long last I had the reflash done earlier this evening. The forester drives the same afterwards, but when putting in the clutch to coast towards red lights I experienced no revving. I'll followup in a week after I've had a chance to drive some more.
  • johnvjohnv Member Posts: 40
    And not an idle rev (dealer called it idle fluctuation) to be seen. I call the problem fixed.

    Curiously just today I received email regarding Service Program WVN-24, regarding a ECM reflash and one-way valve removal to prevent possible catalytic converter damage. I wonder if the reflash I received four days ago covers this? Annoying.
  • whiteoakbayouwhiteoakbayou Member Posts: 2
    My 09 Forester X 5-speed does the exact same thing. It doesn't settle down to idle until the vehicle stops. It's impossible to modulate between on throttle and off throttle smoothly between about 2000 to 2500 rpm.

    I hate the dealership where I bought it and had it serviced for the first 40k mi. I'll take it to the other dealership in town next service and see what they say.

    P.S. It doesn't do it when the engine is warm but not yet up to full temp. Maybe a colder thermostat would help?

    Wish Subaru would publish something so I would know for sure.
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