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Subaru Crew Problems & Solutions



  • phil2000phil2000 New JerseyPosts: 195
    edited March 2010
    I still had the problem after the incline plane idea. It is a flow problem(bottom of radiator is cool and I can touch the top).

    I took of the bottom hose and thermostat, hand cranked the camshaft sprocket and saw that the blades in the water pump turned.

    Next I will see if I can flush water through the radiator with the bottom hose off.

    I can actuate the new thermostat with my fingers. Can't with the old one, but then the problem was a leaky radiator. I will put the new thermostat back in. Or put everything back together without it and see if it overheats to eliminate the thermostat.

    The following is from the shop manual:

    Trouble Corrective action
    a. Insufficient engine coolant - Replenish engine coolant, inspect for leakage, and
    b. Loose timing belt - Repair or replace timing belt tensioner.
    c. Oil on drive belt - Replace.
    d. Malfunction of thermostat - Replace.
    e. Malfunction of water pump - Replace.
    f. Clogged engine coolant passage - Clean.
    g. Improper ignition timing - Inspect and repair ignition control system.
    On-Board Diagnostics II System
    h. Clogged or leaking radiator - Clean or repair, or replace.
    i. Improper engine oil in engine coolant - Replace engine coolant.
    j. Air/fuel mixture ratio too lean - Inspect and repair fuel injection system.
    On-Board Diagnostics II System
    k. Excessive back pressure in exhaust system - Clean or replace.
    l. Insufficient clearance between piston and cylinder - Adjust or replace.
    m. Slipping clutch - Repair or replace.
    n. Dragging brake - Adjust.
    o. Improper transmission oil - Replace.
    p. Defective thermostat - Replace.
    q. Malfunction of electric fan - Inspect radiator fan relay, engine coolant temperature
    sensor or radiator motor and replace there.
  • fibber2fibber2 Mid Hudson Valley, NYPosts: 3,775
    edited March 2010
    My wife used to laugh that I was making thermostat soup. I had a car with a persistent overheating issue in the summer, and the best solution was simply to buy more margin by going with a cooler thermostat (open early). The problem is that thermostats are rather basic/dumb devices that rely on a wax pellet to press against the spring, and the actual opening temperature and amount of lift can vary all over the place. Plus, by design, some open and allow more water to pass than others. Different diameter disks produce different flows. My best find at a automotive swap meet was an old style butterfly type, in which the disk rotates on a hinge, producing almost no restriction when open!

    Anyhow, I set a bunch of them up (hanging - don't let them touch the walls of the pot) with a thermometer on a slow heat, and charted their response to rising temperature. Pretty sick, eh??

    The thermostat is at the bottom of the engine. Is the flow also reversed - in at the top of the radiator, and out the bottom? If so, then the tape you used at the neck is probably no further into the system. If not, you might have ingested it into the engine?
  • phil2000phil2000 New JerseyPosts: 195
    I was able to pour water through the upper hose and it came straight out of the water pump. Then I poured water through the radiator and it came out of the lower hose.

    Now I am going to put it all together without the thermostat and see how it flows.

    What does that mean for the engine? Details please.
  • fibber2fibber2 Mid Hudson Valley, NYPosts: 3,775
    What does a thermostat do?

    Regulated temperature cooling water is one of the factors that determines cylinder combustion chamber temps, and this directly relates to burn efficiency and emissions. With a thermostat, the coolant will remain right around 200'F. Without it, I suspect it will stabilize around 130-140'F. Somewhere I once read that this 60-70' external change will result in a 100-200'F chamber internal change. Think of how your car runs when it is still warming up, and now it never gets there!

    If the coolant remains below a certain threshold (and this varies engine to engine / year to year), the ECM will never switch from 'open loop' to 'closed loop' emissions control. That means it will continue to use a look-up table/map for determining fuel mixture, and not use the oxygen sensor feedback to regulate activity. Or, if it does go closed loop, the reduced burn efficiency will force fuel trim to the extreme end of the spectrum. None of this is probably good for long term operation. At minimum, you will start to throw codes, you could end up with misfires or a damaged catalytic converter.

    Or, I could be full of BS, and this engine can handle it just fine and you will live happily ever after? Inquiring minds want to know!!
  • atticarjatticarj Posts: 1
    Have a 2005 Subaru Forester XS, with 2.5L engine. Purchased new. Have replaced catalytic converter, O2 sensors, power steering pump, and the usual brakes and rotors and timing belt. Approx 5 weeks ago, I was driving at about 45 mph when I noticed that engine RPM started to fluctuate 400-500 rpm, back and forth. After that, the Automatic Transmission Temp light started to flash, and the check engine light came on solid. The car has 139k on it and has has good maint. I took it to the local dealer, where it has been for the past month. They said the codes pointed to the wiring harness for the transmission.They cannot seem to figure out what is causing it, having tried a variety of wiring harness solutions. I have contacted Subaru, and they basically told me what the dealer was doing. Which I knew. At this point, they are planning to splice in ends from another harness, to see whether that works. This is the most bizarre car problem I have ever encountered. To have a dealer and manufacturer unable to repair their own product, and to further have no clue to what is actually going on is mind boggling and costly.

    I have had to buy another car for my wife, but the Forester is worthless as is. If anyone has had any similar problem, or ideas on what might be done to resolve this, I would appreciate the info.
  • ateixeiraateixeira Posts: 72,587
    My '98 Forester had the same air bleeder. Haven't checked the new 09 model.
  • xwesxxwesx Fairbanks, AlaskaPosts: 10,925
    My '96 Outback had one as well and it was handy for initial fill, but I still found that without inclining it and doing the upper hose squeeze method, significant air would remain in the system.

    The '09/'10 Foresters do not have the bleeders; rather, the cap is mounted atop a raised area on the radiator and serves the same purpose.
    2014 Audi Q7 TDI, 2008 and 2013 Subaru Forester(s), 1969 Chevrolet C20 Pickup, 1969 Ford Econoline 100, 1976 Ford F250 Pickup
  • phil2000phil2000 New JerseyPosts: 195
    I am going to try running the engine without a thermostat. I want to see flow through the radiator to verify that the water pump is moving water. At least the engine will not overheat.
  • xwesxxwesx Fairbanks, AlaskaPosts: 10,925
    For a short-term test, it should not harm your engine.
    2014 Audi Q7 TDI, 2008 and 2013 Subaru Forester(s), 1969 Chevrolet C20 Pickup, 1969 Ford Econoline 100, 1976 Ford F250 Pickup
  • fibber2fibber2 Mid Hudson Valley, NYPosts: 3,775
    Agree... Older cars you could do this forever. Computer controlled cars will attempt to compensate for a while. See how it goes.
  • phil2000phil2000 New JerseyPosts: 195
    I spoke with a Subaru service. They told before I tried that, make sure all the air is out of the radiator. Now I thought I had accomplished that. But after review a previous reply to my post and discussions at my job, I will give it another go.

    Service recommended three cycles of the cooling fans with top-offs in between. Also, they said to put a funnel assemble on the radiator.

    Well I am going to get that air out everyway I know how (incline plain, squeeze hose, folk dance, etc.)

    Thanks everyone
  • drkwcdrkwc Posts: 2
    1991 Subaru Legacy 4 cyl, 2.2L AWD, Manua,l 170,00 miles:

    When the weather is below about 45 degrees outside, my Legacy won't idle smoothly or reliably. Instead, it surges between 0 RPM and about 1,300 RPM, up and down, until it stalls. The colder it is outside, the worse the problem.

    When I take my foot off the accelerator while driving, if the outside temp is in the 20s or 30s (or lower), idle drops to nothing and the engine stalls.
    Both of these related behaviors happen while the engine is warm and while the engine is cold, though at startup wihen the engine is cold, it actually will run smoothly for about 20 to 30 seconds before the surging begins.

    I replaced all vacuum lines, cannister, mass airflow sensor, throttle position sensor, purge solenoid control valve. No change, except that I no longer get a diagnostic code indicating that the purge solenoid control valve is stuck open.

    Since that is apparently NOT the problem, I'm hoping someone will recognize it. It is definitely tied to outside air temperature. On those rare wonderufl winter days here when it's 50 or 60 degrees out, the car runs perfectly smoothly, as it should, no idle issues at all. Soon as the outside temps drop, the surging at idle issue begins.

    A search of the forums here turned up two possibilities:

    1. Leaky intake manifold gasket. I'll check for that.

    2. K&N filter -- which I'm using. Next time I'm in town, I'll pick up a paper filter and see if that solves the problem.

    Any other suggestions?

  • fibber2fibber2 Mid Hudson Valley, NYPosts: 3,775
    It sure sounds like a manifold vacuum leak, but probably from something that is not directly connected to the engine. If it were, it would probably seal up once the engine got warm. It is likely something that is staying relatively cold and leaks only when cold. Wonder if it isn't something like the vacuum brake booster.

    Try looking for things like the brake booster that use manifold vacuum but are not as likely to get warm fast, or at all. Pull those lines one at a time and cap the fitting with your finger.

    Long ago I saw a guy use an unlit Bernzomatic torch with the gas on just a crack as a neat leak detector. He waved it over everything and waited for a response in RPM. >POTENTIALLY VERY DANGEROUS<... yet effective.... I cannot believe I even repeated this. DO NOT TRY THIS AT HOME.... PROFESSIONAL USE ONLY.
  • phil2000phil2000 New JerseyPosts: 195
    Prayer and faith got my there.

    Prayed that inclining the car and topping off the radiator after each run cycle would solve the overheating.
    Drove to work and back (76 miles). Stayed within two tick marks of center on the gauge.
  • fibber2fibber2 Mid Hudson Valley, NYPosts: 3,775
    Well done! You earned your cooling system merit badge.
  • phil2000phil2000 New JerseyPosts: 195
    It read about 13volts off and 14.46volts running.

    Is there a rebuild kit for the alternator?
  • xwesxxwesx Fairbanks, AlaskaPosts: 10,925
    Yes, you can rebuild them.

    Congrats, also, on the cooling system - I hope it is a positive sign for future trips! :D
    2014 Audi Q7 TDI, 2008 and 2013 Subaru Forester(s), 1969 Chevrolet C20 Pickup, 1969 Ford Econoline 100, 1976 Ford F250 Pickup
  • phil2000phil2000 New JerseyPosts: 195
    Thanks, Other than Pep Boys and Advance (haven't been there yet), do you have a recommended source for a kit? My alternator is the original (314,959 miles).
  • xwesxxwesx Fairbanks, AlaskaPosts: 10,925
    edited March 2010
    I doubt it matters much. Any auto parts store should have a decent rebuild kit... and I would say yours is due for a rebuild or replacement, though the reported voltages sound like it is hanging in there pretty well.
    2014 Audi Q7 TDI, 2008 and 2013 Subaru Forester(s), 1969 Chevrolet C20 Pickup, 1969 Ford Econoline 100, 1976 Ford F250 Pickup
  • phil2000phil2000 New JerseyPosts: 195
    I want to get ahead of the failure curve.
  • ths258ths258 Posts: 10
    With the 2009 Outback Limited climate control system, I get air flow from the vents even when the system is off. The temperature of the air flow matches the temperature setting at the time of being turned off. Changing to recirculate before shutting off seems to have no effect, as there still air flow from the center vents.

    Is anyone else having this issue? I want to determine whether it is a problem that can be fixed or is just a 'works-as-designed' function.

    Thank you.
  • samiam_68samiam_68 Posts: 775
    Subaru climate control systems are designed by aliens. Mean ones. With many sharp teeth. By design, they don't work. Sorry, but you are stuck with it and not much you can do.
  • ateixeiraateixeira Posts: 72,587
    I call it HAL. ;)
  • bigdadi118bigdadi118 Posts: 1,207
    3 to 5 years ...
  • drkwcdrkwc Posts: 2
    Issue solved.

    It was the Idle Air Bypass Valve.

    I unbolted it, disconnected the air lines, but not the coolant lines, sprayed out the lines and the innards with carb cleaner, then reconnected it. Works like a charm now.

    There WAS quite a bit of gunk in one of the air inlets.

    If the problem returns, I'll pick up one of these valve assemblies at the junkyard and replace mine.

  • fibber2fibber2 Mid Hudson Valley, NYPosts: 3,775
    Interesting find! On that older model, is it remote from the engine? Far enough away that the condition didn't get better as the engine heated up (thermally isolated)?
  • phil2000phil2000 New JerseyPosts: 195
    My overflow tank keeps filling, but the radiator does not draw it back in. Every two days, I remove the tank and pour the coolant back into the radiator.

    I am thinking about removing the lower seal on the radiator cap. This is a new cap from Pep Boys. It is stamped with 16 lbs.
  • bigdadi118bigdadi118 Posts: 1,207
    Subaru OEM Thermostat is specially designed and unique. Do NOT buy other brand or they open & close different the the spec.
    Also change the radiator cap same time as it is cheap.
    Subaru also suggests to use OEM coolant as other coolant may not treat as well to Subie's internal aluminum parts as the OEM coolant.
  • bigdadi118bigdadi118 Posts: 1,207
    Open the radiator cap, with engine running, fill the coolant from the raditor slowly. Top it off then close the cap. Repeat if needed.
  • fibber2fibber2 Mid Hudson Valley, NYPosts: 3,775
    That which gets pushed out into the overflow tank as a result of coolant expansion should get sucked right back into the radiator as the coolant contracts, unless there is a leak in the system somewhere. Most likely it is the new radiator cap's upper seal is not tight against the new radiators upper flange. One of them has a burr or other imperfection. The other possibility is that the hose is not sealed to the nipple/barb on the radiator filler neck, or the hose has a crack.

    When the coolant expands, it pushes out against the 16 lbs (yes, I recently realized that Subi systems run at 1.1 - 1.2 ATM pressure). Older caps were 1.0 ATM, or 14.7 lbs. That probably buys you another 10'F upper end on boiling. Anyhow, it is easy once fluid pushes past the lower seal to run out the barb and down the hose into the overflow. It really stays below the top seal without any pressure - gravity does the job. But if the upper seal isn't 100%, when the radiator pressure goes negative, air is pulled in past the upper seal or hose nipple, and no fluid is sucked back against gravity out of the bottle.

    Look for the simple first. If everything is perfect here, it could still be a failed engine gasket that is providing the one way leak of air back into the system.

    Make sense?
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