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Subaru Crew Problems & Solutions



  • samm43samm43 Posts: 195
    Are you able to confirm there are no vacuum leaks around the power brake booster?

  • compensatecompensate Posts: 212
    I can't say that I know what a power brake booster is. Is that around the master cylinder?
  • colin_lcolin_l Posts: 591
    edited April 2011
    The first thing I would check is the Idle Air Control solenoid (IAC). Very detailed description of cleaning and/or replacing it here:
  • compensatecompensate Posts: 212
    Thanks so much. I will give that a try.
  • xwesxxwesx Fairbanks, AlaskaPosts: 8,391
    Sadly, it could be a differential. The car has more than one, though, so it would be good to isolate the sound as either rear or front/center (I'm not sure that those two are located far enough apart that you could distinguish one from the other). Rear differentials are not terribly expensive or difficult to replace; front or center differentials are a completely different animal.

    Actually, "trans diff clutch & seal kit" could be translated on this basis: the front and center differentials share a housing with the transmission (front is located fore of the transmission and center differential is aft), the center differential uses a series of clutch plates to regulate power to the front and rear axles, and you'd want to replace the seals that isolate the differentials from the transmission as long as you're in there doing work.

    I'm guessing the shop feels there is a problem with the center differential, though I'm surprised it was not discussed with you. I would go back to them and ask for an explanation of the diagnosis (in plain English).
  • danielldaniell Posts: 128
    edited April 2011
    Thank you for the detailed answer.

    The mechanic said something about power not going to the rear wheels (which would point to a center differential problem, indeed). Also said that if it doesn't get fixed, it will ruin the transmission.

    Here is the list of parts for the repairs:
    - wheel bearing $127.03
    - hub $129.55
    - trans diff clutch & seal kit $260 (NIS)
    - 6 ATF $52.00
    - long rear control arm bolt and nut $36.00

    The 6 ATF quarts also would point to something related to transmission or a part that connects to the transmission.
  • compensatecompensate Posts: 212
    Those are expensive parts. You can get Timken wheel bearings from Auto Zone that cost less. And Timken is an excellent wheel bearing manufacturer. I have replace a wheel bearing on my wife's 2001 Forester and used the Timken bearing. I think it was about $55.

  • colin_lcolin_l Posts: 591
    2x retail/autoparts store cost is not unusual for dealerships. However, you rarely can "carry in" your own part.
  • compensatecompensate Posts: 212
    Yes, you cannot usually carry-in your own part to a dealership, but if you have a good, honest mechanic, no problem. Luckily I found one, although it is 22 miles from my house and not on my way to work at all. :)
  • fibber2fibber2 Mid Hudson Valley, NYPosts: 3,732
    I'm wondering if it isn't a leak in the vacuum brake booster itself. If manifold pressure drops dramatically, especially when the engine is still below around 125' F and the fuel system is running open loop, it cannot compensate for the sudden mixture change and stalls.

    Once warm, one of two things happen. Either the leak is temperature dependent, like a worn seal, and it now mates better and no longer leaks. Or, once engine management is running closed loop, the feedback compensates for the pressure drop and corrects the mixture.

    Just another guess, as we cannot see it in action....
  • samm43samm43 Posts: 195
    Yes. Post 19055 (fibber) elaborated for you on where I was going. These (and the others) are just tips for you for a stumped mechanic and yourself. Hopefully the mechanic won't take offense. Good ones always have an open mind and don't get offended if the car owner knows things also in an attempt to troubleshoot.

    Let us know what it was, ok?

  • gibbo91gibbo91 Posts: 1
    i have a subaru liberty 95 model
    and the immobilizer isnt flashing same deal?
    is there anything i can try to fix it? :confuse:
  • xwesxxwesx Fairbanks, AlaskaPosts: 8,391
    Hard to say off the top, but technology changed quite a bit over 12 or so years.

    What is your car not doing (other than the light not flashing)? I am assuming that the light used to flash?
  • kurtamaxxxguykurtamaxxxguy Posts: 1,714
    1. Is synthetic oil what Subaru uses for the front/back differentials? One dealer claimed yes, another said no.

    2. If one attempts running 87 octane, what will happen? I've heard everything from detonation to engine overheating/CHK Engine light on.

    FYI so far I only use Premium gas (92 octane), and the stock Subie diff oil.
  • xwesxxwesx Fairbanks, AlaskaPosts: 8,391
    Unless something changed recently, no, the differentials are not filled with synthetic from the factory.

    I don't know about the 87 octane.
  • phil2000phil2000 New JerseyPosts: 195
    I have a 2011 Outback now and use nothing but regular gas (87). And it runs fine averaging 26 miles per gallon. Matter of fact the manual states&

    Fuel requirements
    -Non-turbo models
    The non-turbo engine is designed to operate using unleaded gasoline with an octane rating of 87 AKI or higher.
  • colin_lcolin_l Posts: 591
    If you were to put 87 octane in your F-XT, there would likely be some detonation even if you attempted to drive moderately. I guarantee there would be detontation if you accelerated at wide-open throttle.

    Detonation isn't an on/off switch. Mild detonation you may not even hear, especially if you have the stereo up loud, windows down or a modified exhaust. The knock sensor hears it, though, and it pulls back ignition timing which generally solves the issue.

    Severe detonation is very serious. You should be able to hear and feel the sluggish response from the engine. The knock sensor will NOT stop severe detonation; by the time you notice it, the knock sensor has already tried to dial back timing and the detonation is still there. You MUST lift your foot to avoid damage to the engine. (Valves, cylinder head, piston, piston rings, connecting rod, rod bearings.)

    I would never, ever drive any car that requires premium fuel with anything less. The 15-25 cents per gallon savings will never be worth the risk.

    And I view cars that merely 'recommend' premium fuel but say they can run on 87 with 'some impact on performance and economy' with high suspicion.. I would run premium all the time.
  • aathertonaatherton Posts: 617
    Subaru fills the diffs with regular oil. I changed both diffs to synthetic at 10k, and the regular oil in the rear diff was already discolored.

    The manual says:
    "The 2.5-liter turbo engine is designed to
    operate using premium unleaded gasoline
    with an octane rating of 91 AKI or higher. If
    premium unleaded gasoline is not available,
    regular unleaded gasoline with an
    octane rating of 87 AKI or higher may be
    temporarily used. For optimum engine
    performance and driveability, it is required
    that you use premium grade unleaded
    Be sure to use premium unleaded
    gasoline of 91 AKI or higher for turbo
    models. If other gasoline (lower than 91 AKI)
    is used, knocking, reduced output
    and poor accelerator response will

    But several people on the Forester Forum have used regular gas in their XT, not noticed any problem, and asked why they should not do it. Evidently they drive so gently that they don't encounter knocking. One wonders why they have an XT.

    The management systems of some engines allow the unrestricted use of both regular and premium gas. The Subaru turbo does not, but the Toyota truck V-6 does:
    From the 2006 Toyota Tacoma truck Owners Manual:
    (2TR-FE is the 2.7L I-4 and 1GR-FE is the 4.0L V-6)
    2TR- FE engine - Select Octane Rating 87 (Research Octane Number 91) or higher.
    1GR- FE engine - Select Octane Rating 87 (Research Octane Number 91) or higher. For improved vehicle performance, use premium unleaded gasoline with an Octane Rating of 91 (Research Octane Number 96) or higher.
  • stackman1stackman1 Posts: 53
    Anyone with that diesel sound should insist on having them check the "timing belt tensioner". I have a 10 y/o 2002 OBS and have paid for numerous visits to the Subaru dealers in various states over the years to figure out why I have always had that horrible knocking sound. Well, turns out I suffered with the noise for 10 years (90K) for no good reason. I brought in my OBS to have my Timing Belt replaced. Turns out the Tensioner was defective all along!!!!!

    I can't tell you how this has changed my opinion of Subaru mechanics. I don't know what they were checking all the times I left it overnight so they "could hear it in the morning". I have no idea how much time and money this irritating noise has cost me. Totally unnecessary.

    So please if you have this 'clacking' sound in the front of the engine - have them check the Tensioner if all else fails. Especially if you are under warranty.

    Scrappy was right on when he replied:

    My dealer now has a stack of service bulletins copied about the cold start "diesel engine" sound that they just hand out to customers who complain--though they will check over the cars to make sure it isn't something else--like a bad timing belt tensioner.

    Unfortunately, after the mechanic changed the Belt and Tensioner - he informed me that my 'left subframe' is so rusted, it may not be safe!!!!! Beautiful....

    Anybody have any ideas about only has 91K on it.....bought it 8/2001 - it is a 2002 OBS Impreza?????
  • colin_lcolin_l Posts: 591
    The subframe comes right out and could be had cheaply from a lower mileage Impreza from the same generation, preferably with the same engine just to be sure. (I think they might be all the same in 2002, but don't quote me.)

    However it is a boatload of labor to replace.

    I would shrug and move on unless we're talking serious perforation. Even in that case, I'd be looking to sell rather than repair unless you're dead-set on driving this car another 100k.
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