90subaruls Posted January 16, 2010 Share Posted January 16, 2010 I have a 1990 subaru legacy ls. has about 155k miles on it. starting a few months ago it would overheat while driving farther than about 5 miles from my house usually on the way back but i would go up and come right back down. now it will overheat and blow cold air with heat on high to those places 5 miles or more. the waterpump was replaced about two years ago(2008). the radiator was replaced in july of 2009,just put a new thermostat in it. My dad has bled it many times to get any air out but it doesnt seem to work at all. everyone says is not a blown headgasket but all signs kinda point to that. Also what we noticed when it does begin to over heat when we hit the gas it will go up higher when we hit the brake it goes down. Any ideas??? Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted January 16, 2010 Share Posted January 16, 2010 Welcome to the USMB. The first gen legacies can be kind of cranky with certain cooling system items. Was the thermostat you put in the car a subaru thermostat? If it was anything but a subaru thermostat, you will have problems. Don't ask me why, but it's been pretty well documented on some of the forums that thermostats other than subaru thermostats can cause you issues. So that's the first thing I would suggest replacing if you don't already have a subaru thermostat. Second, there is a little bleeder screw on the top side of the radiator on the passenger side. You need to remove this screw to properly bleed the air from the cooling system. Remove the bleeder screw, fill the radiator, start the engine, add coolant as necessary until it starts overflowing from the bleeder screw. Put the bleeder screw back in, and top off coolant at the main cap, and put the cap back on. I'd try those things first before messing with head gaskets. You should have heat. I don't think head gaskets are going to cause you to not have heat immediately unless the leak is very bad, but in which case the car would probably not run very well. I'd also suggest checking out http://www.bbs.legacycentral.org if you haven't already found it. Quote Link to comment Share on other sites More sharing options...
90subaruls Posted January 16, 2010 Author Share Posted January 16, 2010 The themostat that was in it before wasn't a Subaru and we went to Allentown and knobels with it never had a problem and those places are 300 miles away. This started up when I began using the heat when the weather turned cold. Quote Link to comment Share on other sites More sharing options...
90subaruls Posted January 16, 2010 Author Share Posted January 16, 2010 We have been bleeding it and doing it again at this moment. Quote Link to comment Share on other sites More sharing options...
johnceggleston Posted January 16, 2010 Share Posted January 16, 2010 is it using coolant? do you have to add it to keep it full? do you have bubbles in the coolant? is there 'gunk' in the radiator or overflow tank? does the coolant smell like exhaust? Quote Link to comment Share on other sites More sharing options...
90subaruls Posted January 16, 2010 Author Share Posted January 16, 2010 Has bubbles little bubbles not much. No to the rest. But we notice when it begins to overheat if we idle it and bring it up to 3000 rpms the temperature will drop. Quote Link to comment Share on other sites More sharing options...
Durania Posted January 16, 2010 Share Posted January 16, 2010 Next thing I would do is replace the radiator cap. Quote Link to comment Share on other sites More sharing options...
90subaruls Posted January 16, 2010 Author Share Posted January 16, 2010 Did that a couple weeks ago( new radiator cap). We flushed out the radiator today nothing came out no blockages. Quote Link to comment Share on other sites More sharing options...
Durania Posted January 16, 2010 Share Posted January 16, 2010 Did you happen to flush the heater core as well? Quote Link to comment Share on other sites More sharing options...
90subaruls Posted January 16, 2010 Author Share Posted January 16, 2010 No, we didn't do that today. Quote Link to comment Share on other sites More sharing options...
wildwagonz Posted January 17, 2010 Share Posted January 17, 2010 Just a useful sidenote regarding your 90 legacy....my Subaru mechanic coworker/friend told me a while back that the 90 legacies with an early production date were notorious for the blocks cracking causing the problems you are experiencing, I ran into this with my 90 legacy as well which was made in 89. Replaced the engine with a 91 2.2 and all has been fine since. Had another friend with the exact same problem too Quote Link to comment Share on other sites More sharing options...
90subaruls Posted January 17, 2010 Author Share Posted January 17, 2010 Were gonna get a Subaru thermostat tomorrow see if that does anything. Kinda sounds like it may be that with looking around about what's the difference between a Subaru thermostat and a aftermarket one. Quote Link to comment Share on other sites More sharing options...
Rooster2 Posted January 17, 2010 Share Posted January 17, 2010 If replacing the thermostat and rad cap don't fix the problem, then I would suspect a bad head gasket. A bad HG doesn't usually occur on a 2.2 motor like yours, but it can and does happen. I had a 91 Leggie with the 2.2 that developed a bad HG, so I have seen it happen. Quote Link to comment Share on other sites More sharing options...
Durania Posted January 17, 2010 Share Posted January 17, 2010 I am sure you'll remember it but make sure you get the Subaru gasket for the thermostat as well. Quote Link to comment Share on other sites More sharing options...
90subaruls Posted January 17, 2010 Author Share Posted January 17, 2010 Talked to my cousin who is a mechanic said it's the head gaskets and their not hard to do. So my dad will be fixing it as soon as I get a car to drive while that one is being fixed. But we are still gonna get the Subaru thermostat. Quote Link to comment Share on other sites More sharing options...
9098 Posted January 18, 2010 Share Posted January 18, 2010 I had the exact same thing on my '90 Legacy @187k. I sold it to a mechanic. I should've fixed it. I miss that car. Don't make the same mistake. Quote Link to comment Share on other sites More sharing options...
travissan Posted January 26, 2010 Share Posted January 26, 2010 (edited) I have been a mechanic for 20 years. Your problem is the heater core is plugged. The cold water from the radiator blows directly at the thermostat keeping it closed even when you are overheating! BAD DESIGN!! If you look at the water flow charts in AllData you will understand. If you rev the motor to 3,000 rpm's the turbulent HOT water at the water pump impeller (near the thermostat) will reach the thermostat to open it and the car's temp will fall very fast to the correct temperature. If you remove the thermostat it will not overheat but will run way to cold. If you bypass (loop) the heater core it will not over heat. The hot water that leaves the heater core returns to the engine at the thermostat. It is the only hot water introduced to the thermostat to keep it open and allow the water to flow from and to the radiator. I normally just back wash the heater core and get large chunks of rust flake out then its fixed. Back wash then froward wash repeatedly many times. Also flush out the motor so you don't re plug the heater core. I hope you have now blown the head gaskets or cracked a head yet. Make sure to run the proper coolant in the car so you don't promote more rust flakes. And bleed the air out as mentioned in detail by other posters. Nobody knows this little secret. Not even Subaru mechanics at the dealer, no TSB (Technical Service Bulletins a special note after the fact to mechanics). After days and days of trouble shooting a 1993 Subaru Impreza (2.0?) I looked at the water flow chart and then it was clear what was happening. This phantom overheating problem stumps the best mechanics and sends many Subarus to the crusher. http://www.subaruoutback.org/forums/printthread.php?s=&threadid=17264 Edited January 26, 2010 by travissan Quote Link to comment Share on other sites More sharing options...
90subaruls Posted January 26, 2010 Author Share Posted January 26, 2010 No we haven't done anything to my car yet I needed a car to go to college and back but I will deff tell my dad about what you said thank you. Quote Link to comment Share on other sites More sharing options...
johnceggleston Posted January 26, 2010 Share Posted January 26, 2010 (edited) This phantom overheating problem stumps the best mechanics and sends many Subarus to the crusher. i don't know much about the cooling system design, but there do seem to be a fair number of 90 - 99 2.2s for sale with overheating and / or head gasket problems on craigslist. if a flush would fix them, what a deal. one of the posts in the above linked thread mentioned one cause as the horozontal design and the coolant not "draining back down" and always being in contact with the gasket.... well if it is a sealed system the coolant never 'drains back down', the engine design does not matter. you really have to take what you read on the internet with a grain of salt. Edited January 26, 2010 by johnceggleston Quote Link to comment Share on other sites More sharing options...
rainman19154 Posted January 26, 2010 Share Posted January 26, 2010 Your problem is the heater core is plugged. The cold water from the radiator blows directly at the thermostat keeping it closed even when you are overheating! The hot water that leaves the heater core returns to the engine at the thermostat. It is the only hot water introduced to the thermostat to keep it open and allow the water to flow from and to the radiator. I normally just back wash the heater core and get large chunks of rust flake out then its fixed. Back wash then froward wash repeatedly many times. Also flush out the motor so you don't re plug the heater core. I hope you have now blown the head gaskets or cracked a head yet. Make sure to run the proper coolant in the car so you don't promote more rust flakes. And bleed the air out as mentioned in detail by other posters. I've seen this same issue/discussion on other forums. The clogged heater will present different runnability issues with different cars but it's often a hidden culprit Quote Link to comment Share on other sites More sharing options...
MilesFox Posted January 26, 2010 Share Posted January 26, 2010 If the heay is blowing cold, then the goolant is too low. If you have bubbles in the radiator, you may have the beginnings of a blown head gasket. I suggest running a can of block sealer. Otherwise it will get worse. Try filling coolant by removing the upper radiator hose to fill the block. this trick has worked for me Try that, and if you still have bubbles, do the block seal. I have had success with 'liquid glass' type block seal, which contains sodium silicate. You have to follow specific directions for the block selar to be effective. DO NOT use bar's leak powder or pellets. this will wreck your heater core Quote Link to comment Share on other sites More sharing options...
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