Whopper Posted December 31, 2016 Share Posted December 31, 2016 Whats the best way to bleed the coolant, I just flushed my car with distilled water but i think there is still some in the car. What else should i do besides opining radiator cap and the drain plug at the bottom. Its a 1994 sport. Link to comment Share on other sites More sharing options...
Brighton96 Posted December 31, 2016 Share Posted December 31, 2016 The normal procedure at the subaru specialty shops is leave the radiator cap off and start the car and let it idle until it's up to temp. They put the heater on the highest setting and just add coolant as necessary. Link to comment Share on other sites More sharing options...
taylormac1993 Posted December 31, 2016 Share Posted December 31, 2016 Start with turning the heater on. A buddy of mine showed me a trick where you remove the top heater hose at the firewall and slowly fill the system at the radiator. That connection on the firewall is the high point in the system. When you get coolant in that part, put the bottom part of the hose on (still adding coolant) and try to squeeze the last bit of air out while you slide the top of the hose on. Its a two man job but so worth it. After doing it this way I never had to bleed the system. Its a good idea when youre done to pop the radiator cap off and start it to make sure you dont need to top it off, but with all of the air out of the high point in the system you should only have to let it run for 60 seconds before you see a difference in coolant level at the radiator. Do not run the car to operating temp with the cap off. It will expand and possibly boil over due to lack of pressure in the system. Pressure in your cooling system raises the boiling point of the coolant, so without a sealed system you will end up losing a lot of coolant and have to start over. Link to comment Share on other sites More sharing options...
MilesA Posted January 1, 2017 Share Posted January 1, 2017 Whats the best way to bleed the coolant, I just flushed my car with distilled water but i think there is still some in the car. What else should i do besides opining radiator cap and the drain plug at the bottom. Its a 1994 sport. There is still fluid in the system, trapped behind the thermostat. You can remove/replace the thermostat (on driver's side where the lower radiator hose attaches to the engine). You can find the procedure described online or in the FSM. Be sure to use a new O-ring for the thermostat. If you choose to get a new thermostat use only Subaru OEM thermostat. Link to comment Share on other sites More sharing options...
taylormac1993 Posted January 1, 2017 Share Posted January 1, 2017 If you choose to get a new thermostat use only Subaru OEM thermostat. This. As someone who works parts, let me tell you the Subaru one is the only one I havent seen fail horribly in these engines Link to comment Share on other sites More sharing options...
Brighton96 Posted January 1, 2017 Share Posted January 1, 2017 This. As someone who works parts, let me tell you the Subaru one is the only one I havent seen fail horribly in these engines +1 On That I had a stant one in my car for about 20k and it hadn't fully failed yet but when I pulled it out, it was partially stuck open. Link to comment Share on other sites More sharing options...
Setnev Posted January 2, 2017 Share Posted January 2, 2017 My radiator has a bleed screw on the passenger side, right above the upper radiator hose. Ever since my rebuild, I have been fighting to bleed air out of the heater core. I did the "cap off the radiator" trick but I seem to lose more coolant than goes in by the time the thermostat opens and I'm still fighting with air/gurgling in the heater core. Car doesn't overheat, the thermostat opens at 195 and temp gauge reading is accurate verified by my scan tool, and heater works great, but the gurgling in the heater core is driving me insane. Link to comment Share on other sites More sharing options...
Setnev Posted January 2, 2017 Share Posted January 2, 2017 This. As someone who works parts, let me tell you the Subaru one is the only one I havent seen fail horribly in these engines Haha. Though I am having mixed results on the OE thermostat. My girlfriend's LL Bean went through 3 thermostats. The first one was the OE we replaced after it overheated the first time, second was an Autozone fail-safe that didn't work at all, and the third was another Subaru OE. On the third one, the lower hose got hot signalling that it was working. That lasted about 40 miles and then it quit opening and the car catastrophically overheated and warped the heads on her EZ30. Link to comment Share on other sites More sharing options...
MilesA Posted January 2, 2017 Share Posted January 2, 2017 There is a great tool to get rid of any air bubbles trapped in the system which is the Lisle Spill-Free Funnel Kit Part #24680. It has worked great for me. The air bubble problem is pretty common especially on the older model Subarus. Air bubbles can lead to mysterious overheating issues and you know that cannot end well. The design and layout of the thermostat has been changed on newer Subarus which helps avoid the air bubble problem somewhat. Link to comment Share on other sites More sharing options...
Setnev Posted January 3, 2017 Share Posted January 3, 2017 There is a great tool to get rid of any air bubbles trapped in the system which is the Lisle Spill-Free Funnel Kit Part #24680. It has worked great for me. The air bubble problem is pretty common especially on the older model Subarus. Air bubbles can lead to mysterious overheating issues and you know that cannot end well. The design and layout of the thermostat has been changed on newer Subarus which helps avoid the air bubble problem somewhat. Thanks, I will be ordering one of these. Sounds like something I should have in my tool arsenal any how. Link to comment Share on other sites More sharing options...
johnegg Posted January 3, 2017 Share Posted January 3, 2017 use advanced search to find : "how to fill and burp your cooling system" posted by "johnegg" filling from empty is very different from topping off. filling 90 - 99 is very different from filling 00+ 2 important factors vent plug and fill slowly. both are REQUIRED!!!!!! Link to comment Share on other sites More sharing options...
Setnev Posted January 3, 2017 Share Posted January 3, 2017 use advanced search to find : "how to fill and burp your cooling system" posted by "johnegg" filling from empty is very different from topping off. filling 90 - 99 is very different from filling 00+ 2 important factors vent plug and fill slowly. both are REQUIRED!!!!!! john, I've researched your method and followed it, but I still have heater core gurgling. It only happens after the thermostat opens. When it opens, the fluid level drops but would be stupid to remove the radiator cap to top it off with the thermostat open and the engine hot. When the engine cools enough for me to remove the cap, I can only get a few more ounces of coolant into the radiator before it's full. At this rate, I'd be doing this for a month. Link to comment Share on other sites More sharing options...
doublechaz Posted January 4, 2017 Share Posted January 4, 2017 Perhaps something is wrong with the siphon in your overflow tank? It should burp that kind of bubble on it's own otherwise. Link to comment Share on other sites More sharing options...
Setnev Posted January 4, 2017 Share Posted January 4, 2017 Perhaps something is wrong with the siphon in your overflow tank? It should burp that kind of bubble on it's own otherwise. That's what I am thinking. The fluid level in the overflow doesn't change at all, hot or cold. Radiator cap? Link to comment Share on other sites More sharing options...
doublechaz Posted January 5, 2017 Share Posted January 5, 2017 That's a good thought. Probably the most likely part of that siphon to fail. Movin' parts an' all. Say, all you guys bagging on non-OE thermostats... When you talk about them failing do you mean failing stuck closed overheat? I think I'm getting that right now. Had good luck with my previous one for several years, but changed it just for age last time I had everything out of the car. Now I'm struggling to keep it under 212F on the highway. Everything else with the cooling seems fine. Link to comment Share on other sites More sharing options...
Setnev Posted January 5, 2017 Share Posted January 5, 2017 That's a good thought. Probably the most likely part of that siphon to fail. Movin' parts an' all. Say, all you guys bagging on non-OE thermostats... When you talk about them failing do you mean failing stuck closed overheat? I think I'm getting that right now. Had good luck with my previous one for several years, but changed it just for age last time I had everything out of the car. Now I'm struggling to keep it under 212F on the highway. Everything else with the cooling seems fine. Yep, the two that I used were stuck closed. That was one OE and one aftermarket autozone failsafe. The autozone failsafe refused to even open at operating temperature. At first I thought it was installed upside down (i didn't install it), but then I took it out and it was installed correctly, just didn't open. Chaz, you should stop by "shop" lol. I'm doing my replacement valve cover gaskets and a power steering reservior o-ring replacement today. Link to comment Share on other sites More sharing options...
MilesA Posted January 5, 2017 Share Posted January 5, 2017 If you compare the OEM thermostat to a generic replacement, the OEM one is typically much more robust and seems to flow better. Also, the OEM one, when correctly installed, has a burp hole to purge any air bubbles from the area around the thermostat. The problem that can happen is that air will get trapped close to the thermostat causing the thermostat not to sense the true water temperature, so it is slow to open, leading to overheating. Subaru changed the thermostat to be oriented vertically instead of horizontally in later model years, which helps avoid the issue with air pockets. Setnev, you could try the Lisle funnel and also keep the front end of the car elevated when putting in the coolant to purge out the air trapped in the heater core area. Just a suggestion. Link to comment Share on other sites More sharing options...
doublechaz Posted January 5, 2017 Share Posted January 5, 2017 Thanks guys. It was working ok for around 30k, but lately... And very recently... I can't decide if I want to pull over and just run without it. With these temps I'm sure it would be "on choke" all the time. I think I'll just limp, but with a couple gallons of coolant and some ultra black. Link to comment Share on other sites More sharing options...
doublechaz Posted January 6, 2017 Share Posted January 6, 2017 Ok. Running at 205 I had a traffic event where I wound it out and temp dropped below 170 and then climbed back up. stuck stat and a rad full of cold water. limping on the heater until I get past this area of arctic weather. Thanks for the info and sorry about the hijack. Link to comment Share on other sites More sharing options...
Setnev Posted January 6, 2017 Share Posted January 6, 2017 Setnev, you could try the Lisle funnel and also keep the front end of the car elevated when putting in the coolant to purge out the air trapped in the heater core area. Just a suggestion. That's exactly what I am going to do. I got the Lisle funnel yesterday from Amazon. I feel like it's Christmas again because this is something I can use because I frequently fix cars with coolant system issues (head gaskets, water pumps, thermostats, and radiators). I'm going to compile a video for my YouTube channel on how to use it. Link to comment Share on other sites More sharing options...
Setnev Posted January 6, 2017 Share Posted January 6, 2017 Ok. Running at 205 I had a traffic event where I wound it out and temp dropped below 170 and then climbed back up. stuck stat and a rad full of cold water. limping on the heater until I get past this area of arctic weather. Thanks for the info and sorry about the hijack. I was gonna say, with the weather here being in the 40's lately, you could run it straight without the t-stat to see how it does. Link to comment Share on other sites More sharing options...
doublechaz Posted January 8, 2017 Share Posted January 8, 2017 I forgot to mention that I drilled a little hole in the tstat before I put it in, just in case it ever stuck closed I could limp. With that and the heater blasting I can just maintain 90 mph at 210F, unless up a mountain. Otherwise it ranges down to 205 highway, and even cooler around town. I'll just blast the heat with the windows down until the dealer gets me a replacement. Only one drain and burp that way. I would have liked to check out that PS work, but I was about 1500 miles away at the time. Link to comment Share on other sites More sharing options...
taylormac1993 Posted January 9, 2017 Share Posted January 9, 2017 Now that im thinking about it I did use that Lisle funnel Miles was talking about. Im telling you guys that hearter hose trick worked perfect. Link to comment Share on other sites More sharing options...
Setnev Posted January 10, 2017 Share Posted January 10, 2017 Now that im thinking about it I did use that Lisle funnel Miles was talking about. Im telling you guys that hearter hose trick worked perfect. So far filling it with the Lisle funnel worked getting the air out of my heater core. There was A LOT of air bubbles that burped out almost immediately and when I ran the car for about 30 minutes even more came out. I put in almost a quarter gallon of coolant into the engine with the funnel. In the future, I will definitely try your method Taylor and then finish it with the funnel on the radiator connection. Link to comment Share on other sites More sharing options...
doublechaz Posted January 10, 2017 Share Posted January 10, 2017 My funnel is on the way. It sounds a lot easier than the vacuum method I've been using. So, in theory, tomorrow I get my tstat. Friday for the funnel. Should be able to stand waiting that long. Link to comment Share on other sites More sharing options...
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