floater Posted December 31, 2008 Share Posted December 31, 2008 96 Outback 156k miles Noticed that the radiator overflow had some black gunk in it. I put my finger in and it looks like oil. Tank also smells like oil. Car has been using oil. Car has always passed smog. Took it in to shop and gave symptoms and mechanic told me that subaru uses radiator to cool transmission and that they would need to remove radiator and send radatior for testing to confirm it was not transmission oil? WTF? ever heard of this?:-\ What are my options? Quote Link to comment Share on other sites More sharing options...
Gloyale Posted December 31, 2008 Share Posted December 31, 2008 Well, the coolant chambers are all physically above the oil return passages. And I doubt that a pressurized system would allow oil to seep in. It would have to be from the pressurized oil feed lines to be at the HG, but unlikely. Trans fluid is cooled in a chamber on the side of the radiator. Actually this warms the trans oil as well in cold weather so it's really more of a heat exchange than a true cooler. Anyhow, possible, but not too common. Are you sure it is actually oil and not residual sludge from some additive? Quote Link to comment Share on other sites More sharing options...
floater Posted December 31, 2008 Author Share Posted December 31, 2008 I don't really put anything in the car except techron in the gas tank right before I change the oil. Is there any confirmed way of testing? Well, the coolant chambers are all physically above the oil return passages. And I doubt that a pressurized system would allow oil to seep in. It would have to be from the pressurized oil feed lines to be at the HG, but unlikely. Trans fluid is cooled in a chamber on the side of the radiator. Actually this warms the trans oil as well in cold weather so it's really more of a heat exchange than a true cooler. Anyhow, possible, but not too common. Are you sure it is actually oil and not residual sludge from some additive? Quote Link to comment Share on other sites More sharing options...
idosubaru Posted January 1, 2009 Share Posted January 1, 2009 i wouldn't put much faith in a 10+ year old coolant overflow tank. they are USUALLY dirty on all the subaru's that pass through my hands (like dozens of them). they just get dirt in them from not being tightly sealed. now, that doesn't mean you don't have a problem, but that's not the way to diagnose. you didn't say if it was manual trans or auto or what engine is in the car. in 96 the manual OBW got an EJ22, the automatic got an EJ25. from your comments sounds like it's an automatic with an EJ25. they rarely loose headgaskets without overheating. has the car ever overheated? how much oil is needed to be added between oil changes? and how often are you changing the oil? Quote Link to comment Share on other sites More sharing options...
floater Posted January 1, 2009 Author Share Posted January 1, 2009 yeah it is an automatic. it hasn't overheated since I have driven it. I have been adding water/coolant a few times since last weekend when I noticed the temp gauge moved up but didn't go up much and then returned to the normal range. It uses a quart every 500 miles or so. The stuff in the overflow tank is black and gunky and smells like oil. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted January 1, 2009 Share Posted January 1, 2009 wow. a quart every 500 is terrible. it could easily be leaking it too, any signs of leakage? my guess is it's a very dirty engine if it's been this poorly maintained. it could have just overheated due to the coolant being low. if you want to keep this engine at all, do not let it run hot at all. it's hard to say. it could be separate coolant and oil leaks. a $10 clamp and hose for the coolant and a $5 oil seal/gasket. i'd want to verify the coolant and oil are mixing. have the oil drained and inspected for froth. remove the oil cap - is there a milkshake substance under the cap? look at the dipstick and drained oil - preferrably an open container to drain the oil into - look for coolant/oil mixing. a compression test may verify the condition of the head gasket as well and is very easy to do. Quote Link to comment Share on other sites More sharing options...
Rooster2 Posted January 1, 2009 Share Posted January 1, 2009 I have never heard of removing the radiator, so it could be sent somewhere for testing. I have had many cars that developed sort of a scummy oily dard residue inside the over fill tank. There never seemed to be a problem. I just figured it was old antifreeze additives that were presenting themselves. A quart of oil every 500 miles isn't that bad. If it were me, I would keep on driving the car the way that it is, and just keep a close eye on the temp guage for any over heating. The radiator testing just sounds like BS, and a waste of your money. Suggest that you remove your remove your over flow container, clean it out real good, and reinstall. Keep an eye on the over fill. I bet it takes a long time to get yucky again. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted January 1, 2009 Share Posted January 1, 2009 oh yeah, i agree the radiator testing sounds kind of corny. but i would look into this a bit more, i wouldn't ignore it unless you're ready to just run this thing into the ground. a quart per 500 mile leak could easily turn into "all your oil on the ground while driving" and ruin your engine. it's way too easy to run low and do engine damage. seen it happen numerous times. Quote Link to comment Share on other sites More sharing options...
rverdoold Posted January 1, 2009 Share Posted January 1, 2009 I have a 91 legacy automatic and never had had any problems of transmission oil getting into my radiator/coolant. Keep in mind that the smell of transmission oil is completely different than that of motor oil. (just smell the dipstick, sorry for me being a chemist and using the nose as a tool). However i have blown head gasket and that is why my radiator got a small crack in the plastic side of it. This was caused by the increased pressure from the little bit of exhaust gasses coming in the cooling system. I never had the engine overheating, neither the needle ever went further up then the middle. To see if your HG is blown you can try a few things: - rev to 2500 rpm with cold engine (not frozen though) with the radiator cap removed if the coolant starts to come out by really flowing then it might be possible the HG is bad. - Remove radiator cap and put a piece of metal on the edge so that when you put the cap back the overpresure valve is open. Now you should be able to see airbubbles in your overflow tank from time to time (mostly all the time but i don't see them every time i look) These are generated by exhaust gasses. - measure compression of each cylinder will tell you I am not going to fix my nearly 20 year old car. Currently i am driving 5.000 miles with a depresurized cooling system and probably already 15.000 miles with a bad HG. I drove the cooling system like that in cold and warm weather and never had problems even up to elevations of 3.000 ft. The car is not using coolant (loosing, i fixed the radiator with sicaflex) and oil is normal. Quote Link to comment Share on other sites More sharing options...
floater Posted January 1, 2009 Author Share Posted January 1, 2009 I'm wondering if I get the radiator/overflow tank tested for petroleum gases. I heard that shops have a device that can do this or it can be done via a chemical test. To me that is pretty definitive. Quote Link to comment Share on other sites More sharing options...
Rooster2 Posted January 1, 2009 Share Posted January 1, 2009 I'm wondering if I get the radiator/overflow tank tested for petroleum gases. I heard that shops have a device that can do this or it can be done via a chemical test. To me that is pretty definitive. It has been a while, but I remember about 15 years ago that a shop tested my VW for head gasket trouble by using chemically treated paper which was inserted into the neck of the radiator into the coolant. Upon removal, if the paper changed to a certain color, that was the indication of exhaust in the cooling system. The process reminded me of using Litmus paper to detect an acid or a base from High School chemistry class. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted January 1, 2009 Share Posted January 1, 2009 you might even be able to find an exhaust gas test kit at a local auto parts store as well. they are fairly good, but not as definitive as you'd think on newer gen stuff. if it tests positive - you're probably hosed. they can give a false negative though - meaning you could still have bad head gaskets but "pass" this test. i've seen it happen, only on EJ engines like you have. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted January 1, 2009 Share Posted January 1, 2009 did you buy this car used and how long/many miles ago? if this is a bad headgasket my guess is that it was replaced before but they didn't do a very good job. odd for this engine to blow a gasket like this. Quote Link to comment Share on other sites More sharing options...
floater Posted January 1, 2009 Author Share Posted January 1, 2009 Two previous owners before me. I have all the receipts on the car. I looked through them and don't find it was ever done. I have had it about 4 years. Quote Link to comment Share on other sites More sharing options...
zedhead Posted January 2, 2009 Share Posted January 2, 2009 If the overflow tank is all gunked up, it's a telltale sign of head gasket failure. You can do a coolant pressure test to confirm that the pressure is over 10 psi. Also, the Exhaust test kits will tell You if exhaust gasses are present in the coolant Quote Link to comment Share on other sites More sharing options...
Gloyale Posted January 2, 2009 Share Posted January 2, 2009 If the overflow tank is all gunked up, it's a telltale sign of head gasket failure. It can be an indicator, bit I wouldn't call crud in the tank "telltale" I've seen plenty of Soobs with gunky overflows that DID NOT have blown Headgasekts. It's possible you are seeing water swelled and disolved coating from the headgasekt flaking off. The first EJ motors used a HG design with coating over the whole surface. The exposed "ring" around each cylinder on the block side eventually swells and peels off. The resulting mass of gooey, partially disovled graphite flows through the system. Often contributing to a failed HG, not the result of. The newer HG design only has coating on the block side where the block actually makes contact. Clean out the crap, flush the coolant, check for any and all leaking hoses. Look for leaks at the crossoverpipe. Clean your radiator cap. Keep her full of coolant and watch your temp gauge. You'll be fine. Quote Link to comment Share on other sites More sharing options...
zedhead Posted January 3, 2009 Share Posted January 3, 2009 (edited) It IS a tell tale sign. There's a difference between radiator sealers, additives,etc, and the oily mess that phase 1 EJ25's deposit inside the reservoir. Also, if the car has seen any kind of decent maintainence, there should be nothing but clean coolant in the reservoir. Another tell tale sign is if the gunk smells like fuel/exhaust. Cold starts will allow the unburned fuel/exhaust gasses into the coolant. So, Smell the gunk! Edited January 3, 2009 by zedhead Quote Link to comment Share on other sites More sharing options...
floater Posted January 4, 2009 Author Share Posted January 4, 2009 Thanks for all of the advice. One other symptom I noticed after I was reading on this forum and checked. Car at operating temperature and cap off overflow tank there are bubbles comming up. I am going to do a total drain and flush of raditor. I had to order a 14mm hex drive socket so I can remove the two plugs for the block. Will also clean out overflow tank. I then will refill with new coolant and see how quickly the overflow becomes dirty. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted January 4, 2009 Share Posted January 4, 2009 Thanks for all of the advice. One other symptom I noticed after I was reading on this forum and checked. Car at operating temperature and cap off overflow tank there are bubbles comming up. now we're getting somewhere. that is typical Subaru head gasket symptoms. sounds like a good chance you have headgasket issues. Quote Link to comment Share on other sites More sharing options...
rverdoold Posted January 8, 2009 Share Posted January 8, 2009 I am going to do a total drain and flush of raditor. I had to order a 14mm hex drive socket so I can remove the two plugs for the block. Will also clean out overflow tank. I then will refill with new coolant and see how quickly the overflow becomes dirty. It is much easier to disconnect the lower coolant pipe from the engine with the car lifted up from the back. I heard that putting the plugs back might result in leakage. Quote Link to comment Share on other sites More sharing options...
floater Posted January 10, 2009 Author Share Posted January 10, 2009 Really, the Haynes manual recommends removing them. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted January 10, 2009 Share Posted January 10, 2009 i wouldn't put too much faith in the Haynes manual, they've been dead wrong before, though this seems relatively benign. Quote Link to comment Share on other sites More sharing options...
johnceggleston Posted January 10, 2009 Share Posted January 10, 2009 this may be one of those cases where 'just because you can do something, doesn't mean you should'. Quote Link to comment Share on other sites More sharing options...
rverdoold Posted January 10, 2009 Share Posted January 10, 2009 disconnecting the lower coolant pipe is much easier than re-sealing those two plugs. It's just one hose connector. To fill up the system connect the hose (of course) jack up the front of the car and remove the venting cap on the opposite side of the radiator. Now slowly poor new coolant into the radiator main filler hole. This works fine and is very simple. (and just for sure, make sure coolant has cooled down before working with it) Quote Link to comment Share on other sites More sharing options...
floater Posted January 12, 2009 Author Share Posted January 12, 2009 thanks, that does sound much easier. disconnecting the lower coolant pipe is much easier than re-sealing those two plugs. It's just one hose connector. To fill up the system connect the hose (of course) jack up the front of the car and remove the venting cap on the opposite side of the radiator. Now slowly poor new coolant into the radiator main filler hole. This works fine and is very simple. (and just for sure, make sure coolant has cooled down before working with it) Quote Link to comment Share on other sites More sharing options...
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