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Subaru Crew Problems & Solutions



  • lg05legacylg05legacy Posts: 13
    I have recently been noticing that my temp. gauge is spiking in stop and go traffic if I drive for about 30 mins. or more.

    Example: I'll be driving at ~70mph on the highway for about 30 minutes, then if I hit stop and go traffic, the temp spikes.

    Normally, after the car warms up, the temp gauge runs at 9 o'clock or half way between cold and way too hot. Yesterday after driving consistently at 70mph for about 2 hours on the highway, I drove around town (stop and go) and noticed the temp gauge was almost into the red.

    This is very concerning to me because I purchased my '05 Legacy as a certified used vehicle in 2009. It now has about 56000mi on it, and it is the only mode of transportation I have to get to work every day. Would anyone have any helpful information on this issue??

    Thanks in advance!
  • fibber2fibber2 Mid Hudson Valley, NYPosts: 3,732
    We'll assume that you have checked the coolant level and that you are full in the radiator, with some in the overflow tank.

    What you describe (acceptable temp gauge reading during high speed driving followed by a spike when you get off the highway) sounds all too characteristic of a head gasket problem. Fortunately, as a Certified Used, you should be covered if that is what it turns out to be.
  • phil2000phil2000 New JerseyPosts: 195
    I have the same problem on my 2000 Forester (320K miles). I thought it was the aftermarket thermostat I put in (it had no jiggle pin). Since there is oil leaking around the head and block (dealer said head gasket) that might be the problem.

    Could we get an explanation why the head gasket would cause the problem? Because I would think there would be water in the oil and vice-versa.
  • rebel71rebel71 Posts: 87
    Hi all I'm asking for the help of anyone who owns an 06-08 Legacy that has had bad wheel bearings replaced to please post when the failure mileage occurred and date if possible. I noticed that showed a TSB issued by Subaru 5/2008 for owners of 05-06 Legacy/Outback rear wheel bearings produce a "whining" sound saying it doesn't pose a safety problem, but they are covering the repair at no cost to you and extending the warranty. The reason I'm asking for your help is that I've had an intermittent noise that started at 13,000miles on my 08 Legacy(bought new) drivers front wheel area, of course the sound stops when I get to the dealer. All signs point to wheel bearing. They can't diagnose till they hear the sound.
  • fibber2fibber2 Mid Hudson Valley, NYPosts: 3,732
    edited May 2010
    Phil, I'm not sure that I can give you a 'complete' explanation, but I'll tell you what I know (or think I know???).

    Surrounding the cylinder bore are multiple passages that bring coolant around the head, and oil passages that lube the cam and valve stems. The head gasket has of course the large center hole for the combustion chamber, plus these separate small ports for oil and coolant, and the head bolt holes. Net is that there is really very little gasket material in places.

    Structurally, there also isn't a lot of ribbing between the bore walls and the rest of the block. It's called an open deck design, and thus it has more flex during thermal cycling. The theory is that the flex promotes scrubbing, which eventually degrades the gasket. Initially, an outer coolant passages at the back of the block (#4 - drivers side) develops an external leak which tends to drip on the exhaust, giving a sweet smell that is the first tip-off of problems. Eventually, it allows leaks to the cylinder.

    As cylinder pressures are way higher than the water jacket, the hot exhaust gases find their way into the coolant. This causes local boiling and hot spots, which the temp gauge picks up usually prior to there being real engine damage (hopefully). It also tends to force coolant out into the expansion tank, which may overflow if enough gases build up.

    The leak is usually so small that it tends to be one way for a while - hot gases enter the cooling jacket, but little coolant finds its way into the cylinder after shutdown. Eventually it degrades, and the flow becomes bi-directional. When this happens, cylinder bore damage occurs, blocks crack from more severe overheating - end of show.

    The location of the breach also tends to not involve oil passages, and thus there is limited or no mixing of oil and antifreeze for a while until it all begins to break down.

    And this is the theory which is mine! (as a professor of mine once put it...).
  • Interesting problem, e-mail back up. Let me add, are the cooling fans coming on? Is the radiator clear for proper air flow. Some people block airflow in colder climates during extreme cold.

    Another thought, if exhaust gas leak, sometimes you can find that by holding a dollar bill to the exhaust after the car has heated up. If it gets wet, you have a problem. On a cold engine, pop the radiator cap and start the engine and watch for exhaust gases to vent front radiator cap. This works with more extreme cases. Final step would be to pressure test the system. Another thought, is the correct temp stat installed. Is it opening at the correct temp? Put it in a pot of water, boil and observe the begin to open and fully open points. Never assume a new part is good! Another over looked problem would be a clogged radiator. Being a newer car, there could be some packing material stuck in it some how. Past this, it is think way out of the box!
  • Subaru has quite a history with wheel bearings....period! I suspect the problems of the past extend to the present! Click on my handle and pull up the posts listed in it.

    Everyone else. Addition to the last service post on the 40K mileage service miles failure. I believe that unit was at 258K miles then. Carefully inspect the halfshaft surfaces for smoothness. Clean up or replace as needed. If it damages your seals, the bearings will fail sooner. Also, I have now verified there is no physical difference between OEM, National and Beck Arnley seals....other than price!

    Bottom line, Subies do not care for dirt or water around the wheel bearings! Keep out of the stuff or plan on replacing wheel bearings more often! That is now SOP on all of them in our fleet, including $8 a can synthetic grease!
  • xwesxxwesx Fairbanks, AlaskaPosts: 8,391
    Based on my own experience with the issue, I think your theory is a pretty good one.

    We hear often about the highway driving followed by stop/go resulting in temperature spikes, and I suspect that this is mostly a result of the reduced airflow over the exterior of the engine rather than something different happening inside the engine. When those gases get into the coolant passages, it reduces the effectiveness of the coolant by disrupting flow and, possibly, through the resulting loss of contact with the metal surfaces.
  • lg05legacylg05legacy Posts: 13
    First, thank you all for your thoughts on this issue. Just found out today that my vehicle is still under warranty (extended Gold Plus package) so if it is a head gasket, I'll be covered.

    Second, Xwesx: Any thoughts (short of installing a hood scoop) on how to remedy this reduced airflow issue? It is somewhat of an alarming issue when you're 50 miles from where you want to be. I've toyed with the idea of switching my stock intake with a cold-air after market one...
  • xwesxxwesx Fairbanks, AlaskaPosts: 8,391
    edited May 2010
    It is merely an artifact of the speed of the car, so there is nothing (practical) you can do. The hood scoop won't really do anything to help on the scale you're talking about. The engine generates a lot of heat while operating and if the coolant is not operating effectively to transfer that heat to the radiator, heat loss to the air around the exterior of the engine will only do so much. It is not air flow that is causing the problem....

    Maybe recasting the block with a series of cooling fins surrounding it coupled with a massive blower fan? :P
  • phil2000phil2000 New JerseyPosts: 195
    At 319,703 I replaced the right reat bearing. I have been getting 275K+ out of mine. The front right is still original. But will replace and the half shaft during the summer.

    I do not let flooded roads stop me. I've driven through a couple that were up to the license plate.
  • fibber2fibber2 Mid Hudson Valley, NYPosts: 3,732
    I guess I stopped short in my description of why the reduction in speed sets this off. I believe that during the high speed driving a certain amt of hot gases get introduced to the cooling system. Everything is still OK at this point because the high airflow thru the grill coupled with the high volume flow rate of the water pump keeps the 'bubble' in motion and dispersed. In essence, the cooling system has the capacity to keep up with the intrusion.

    When you slow down, the worst happens. The fresh air flow rate drops, so you loose transfer capacity. The steam bubble coalesces at the high point in the block and heads, where it causes rapid localized temperature spikes. This non-uniform thermal expansion can do major damage.

    Again, just a theory based on observation... Very non-scientific.
  • phil2000phil2000 New JerseyPosts: 195
    That would explain a few things:

    With a steam bubble floating around it could find its way to the temperature sensors and cause a quick rise. While stopped, I increase rpm to 1.5K, the bubble starts to disperse and indicated temp decreases until the bubble coalesces again. I saw that today.

    So just replacing the thermostat with one that has a jiggle pin will not solve the problem?
  • fibber2fibber2 Mid Hudson Valley, NYPosts: 3,732
    Again, it is one possible reason. As girlcarbuilder (?) pointed out, are your fans running? Is the radiator filled with calcium and other junk from using tap water rather than distilled? These could also cause similar problems.

    IIRC, I think I saw two temp senders in a schematic. One goes to the dash gauge, the other to the ECM for running the fans, determining transition from open to closed loop fuel/air control, etc. This or another bad sensor can lead to an overly lean mixture or highly retarted timing, or even a delay in the fans from coming on which can also cause a temp spike. Everything is inter-related.

    Sorry, but that old tach-dwell meter won't help you much anymore!
  • Another thought this morning. Phil, if I recall is one of the high milers out there. If the fans are running, he needs to check the fan bearings for excessive side play. If sleeve bearings, they will slow down a lot and not cool properly. If ball bearing, they should turn very easily when both hot or cold.They will appear to be running, but are not doing a good job from a lower rpm. Grab the edge of the fan blade with the car turned off and cool. Try to push it sideways. If it moves a little bit, pull the fan and further inspect the motor. This will also caused the a/c not to cool as well. I saw this problem on a 1980 Subie years ago.

    This could be the answer on a MO fleet unit with a poor a/c cooling complaint I deal with. I will have to call them and advise. That one is at 265K now, a 97 Legacy Brighton.
  • phil2000phil2000 New JerseyPosts: 195
    You have a point. Those fans have seen 320,343 miles. Just like the wheel bearings, idler pulleys, and piston slap wear, they too should replaced.

    Can you tell me how to replace the boots on the tie-rods?
  • lg05legacylg05legacy Posts: 13
    So just to update everyone that replied to my initial post of an overheating issue in stop-go traffic, I finally took my Legacy to the dealer to get it looked at.

    Their diagnosis: clogged radiator fins. Having that replaced so I'll hopefully be good to go after the part gets shipped overnight & installed. At least it wasn't the head gasket like I initially thought.
  • fibber2fibber2 Mid Hudson Valley, NYPosts: 3,732
    edited May 2010
    I assume that they mean clogged tubes (internal clog) as opposed to a bug encrusted outer fins?

    In the old days (yes, I'm old...), I'd take a clogged radiator to a local shop, they would remove a side tank, rod it out, 'pickle' it in a caustic brine, resolder the tank and paint it. All for about 1/3 the price of a new radiator. Guess nobody does that today with crimp seal tanks. Pull it and throw it away...

    Make sure they chemically flush out the entire system. If the radiator got that bad, the heater core isn't far behind.
  • ateixeiraateixeira Posts: 72,587
    Glad to hear that is was something simple (and cheap) and not a gasket after all.
  • Glad to be able to steer you in the right direction. The final proof will be if it resolves the issue or not.

    Something else just came to mind about some of these newer cars I am seeing with the more open areas below the bumper. I am seeing a lot more rock damage on condensers, tranny coolers or radiators....whatever is exposed under there. Am thinking of some kind of grill material to cut down on that damage. Too many crushed fins cuts down on cooling ability.
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