Afrey1143 Posted February 7, 2015 Share Posted February 7, 2015 Hello everyone! First post here! Which I consider a good thing because Iv owned my 1998 Subaru Legacy GT (automatic 145k) for over a year now with no problems. Anyways, I'm sitting at a stop light one day and I saw steam coming from the front passenger corner of my hood. Pulled over and saw the steam coming from passenger side top corner of the radiator. I noticed a leak coming from the bottom of my radiator. Replaced it. Started driving the next day and got about two miles from home and it was overheating. Took it home and spent lots of time trying to making sure I got every last air bubble out of the system. Still overheated. I replaced the themostat. Still overheated. The water pump seems to function and no coolant is leaking from the weap hole. But is most certainly going to be part of the next step. One point to mention; if I start the car and let it sit in my driveway at idle. It won't ever overheat. The overheating only happens when I drive the car. And more specifically, when you come to a stop and have to start again. I can drive 5miles from my house without having to stop. Iv driven the car down the road at 30 and at 65 and it doesn't overheat. But when I come to stop and have to accelerate back up to speed the car overheats immediately. (Addition: Iv filled the system with coolant multiple times, (never seen and sludge) and the coolant system is full of coolant, I promise you that!) unless there's a secret Subi trick I don't know about... Iv read a lot of different posts, none were specifically hitting my points. If anyone has a article/thread that covers this, please refer me. From my readings Iv come to believe a possibility that air is being trapped in the engine and the proper fix is to pull the heads off and replace as necessary. Any thoughts and ideas are appreciate! Sorry for my lengthiness! Link to comment Share on other sites More sharing options...
johnegg Posted February 7, 2015 Share Posted February 7, 2015 if you did not buy the t-stat from suabru it will cause problems with over heating. get a subaru t-stat. fill the system with 6 qts of coolant, any less and you have not filled it, and it will overheat. measure so you will KNOW. remove the vent plug when you fill the system, if you don't it will not fill completely, and it will overheat. fill the system SLOWLY, if you don't it will have an air lock, and it will overheat. you are not the first person to say , ''i know the system if full, what can this be?'' read this: how to fill and burp your cooling system. - burpcoolingsystem - Subaru Legacy Forums . Link to comment Share on other sites More sharing options...
Afrey1143 Posted February 7, 2015 Author Share Posted February 7, 2015 I will follow your advice per the post above. But I'm curious as to how I can be sure I purchase the right thermostat. Do you have a part number or anything? Link to comment Share on other sites More sharing options...
johnegg Posted February 7, 2015 Share Posted February 7, 2015 suabru only has one t-stat for the legacy, forester and impreza in the 90s. you cannot buy the wrong one if you get it from the dealer. but if you want a part number, look here: http://opposedforces.com/parts Link to comment Share on other sites More sharing options...
Afrey1143 Posted February 10, 2015 Author Share Posted February 10, 2015 Alright, I bought a new t-stat from the Subaru dealership today. Took out the replacement, and drained the coolant. I followed the coolant refilling process to a T. Breather valve open. Used a siphon in a gallon jug to assure that the fill was slow. I home brew, so I had a few extra feet of small diameter clear tubing laying around. I Filled another jug with two quarts Exactly... Only got one quart into the system before it was full. Which doesn't suprise me too much. I drained as much as possible; from both the radiator drain valve as well as the but popping off the lower radiator hose from the t-stat housing. (Radiator cap off of course) I started up the car and let it run to temp and am letting the engine cool down. But I have a problem; Its freezing cold in Illinois right now, and I don't think the thermostat is opening at all. I let the car run for 15-20min it got to normal operating temp (temp gauge just under half) but the fans won't turn on and the lor radiator hose is not very warm. Any suggestions? I don't want to be this precise and then not get the t-stat to cycle and suck in any needed coolant and mess the whole process up. Link to comment Share on other sites More sharing options...
twisty Posted February 10, 2015 Share Posted February 10, 2015 in the fsm it says to hold the throttle at like 2500 rpm for 3 minutes (or something to that effect) to get the engine up to operating temp and trigger the fans. mebbe that would help get it to warm up more thoroughly? Link to comment Share on other sites More sharing options...
Osei Posted February 10, 2015 Share Posted February 10, 2015 You need to fill the block first by using the upper radiator hose. Filling any other way will not fill the system as the t stat is on the lower part of the engine and will not let a lot of coolant pass through the jiggle valve. O. Link to comment Share on other sites More sharing options...
Afrey1143 Posted February 10, 2015 Author Share Posted February 10, 2015 So you are saying disconnect the upper radiator hose from the radiator and add the coolant right into the upper hose? I didn't see any mention of that in the guide john posted... Iv tried holding the throttle open, I'll try again and do it for a longer period of time Link to comment Share on other sites More sharing options...
Osei Posted February 10, 2015 Share Posted February 10, 2015 Yes. Subaru's are unlike 90% of engine systems out there, because the T stat is on the bottom of the block under the water pump preventing coolant from filling the block. Trying to get the system up to temp allowing the t stat to open will only work if there is minimal coolant in it, because so much will overflow before the stat opens. O. Link to comment Share on other sites More sharing options...
Afrey1143 Posted February 11, 2015 Author Share Posted February 11, 2015 I'm jut clearifing here. If the system is full all the way up to the breather than that coolant is going to go into the upper radiator hose. The hose is lower than the breather.... Furthermore if I were to pull that upper radiator hose off, a bunch of coolant is going to flow right on out of there Link to comment Share on other sites More sharing options...
monkeyposeur Posted February 11, 2015 Share Posted February 11, 2015 I've never needed to fill the coolant system by removing the upper radiator hose. A long necked coolant funnel has always worked for me. That and squeezing the upper and lower hoses. Link to comment Share on other sites More sharing options...
Afrey1143 Posted February 11, 2015 Author Share Posted February 11, 2015 I'm not familiar with a long necked coolant funnel. How is it different from any other funnel? Basically I filled the system up to the top and then some. It was full on the breather cap side, and full in the radiator fill neck. With the breather being higher than the upper radiator hose, I don't seem a physical possibility that the coolant doesn't flow down into the engine block. Also when I was siphoning the coolant in, I could hear from the inside the breather the coolant dripping down. This is not to say it's impossible for air to get trapped in that area. But I thought that was the idea of filling slowely, was to prevent this! But I'm still left with my concern of the system not being full, due to the t-stat not opening and therefore the possibility of air stuck somewhere in the cooling system Link to comment Share on other sites More sharing options...
johnegg Posted February 11, 2015 Share Posted February 11, 2015 i don't know why it did not fill totally, unless some coolant was still in the system?? was car sitting at an angle? standard US qts? anyway, i doubt 1 qt low is enough to cause overheating. and i agree the engine may not get ''hot'' enough at idle in illinois in the winter to open the t-stat. but it probably has. regardless, i would fill the over flow bottle to the line, and drive it. the heat up cool down cycles will certainly open the t-stat, and eventually circulate any ''air'' which will move to the top. and then when the coolant pressurizes the system air and coolant will be pushed into the over flow. as the system cools it will draw coolant back into the system from the overflow. over time this will expel all the air in the system. IF you keep the proper amount of coolant in the over flow. you can also check the level in the rad each morning before you drive. if low add a bit. this will get it filled sooner. the only way this will not work, if the coolant level is so low that the coolant will not circulate. you will know this is happening if your heater blows cold air, no heat. but i doubt missing one qt will cause this . but keep an eye on your temp , just in case. . Link to comment Share on other sites More sharing options...
Afrey1143 Posted February 15, 2015 Author Share Posted February 15, 2015 Thank you John for helping out once more! So one more time I made sure to follow all instructions. Let the car get warm in the garage, everything went normally. Took it around the block, around another block, and another. Fans turned on, no overheating, pushed a little fluid into the overflow. So I take on a road up to 45mph, drove about two miles temp gauge starts to rise. I pulled over, try and let the coolant circulate. It had pushed more coolant into the overflow, up to the top. But it won't pull any coolant back into the system. It just pushes it out. Also when it overheated, it wouldn't go back to down to operating temp. Idk why it won't take any coolant back into the system, any ideas?! I did check the overflow hose for blockages, nothing in there. I'm assuming that it won't stop overhearing because its pushed enough coolant out of the system. One more point of interest; when I started it and let it idle, it was blowing Luke warm air. But when I started driving it and it started pushing the coolant out the air turned cold. So that could be from coolant lose. Or a blockage, idk. I'm really thinking that combustion gases are being trapped, but maybe there's another reason why the cooling system won't allow coolant to flow back into the system?! Thank for you help folks! It was a good effort to and get around that huge part bill Link to comment Share on other sites More sharing options...
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