SubieSteve Posted November 5, 2008 Share Posted November 5, 2008 I finally got my legy back from the body shop the other day. $9,500 in damage!! At least only Subaru OEM parts were used in the repair. Car looks good too - all seams line up, tight/no rattles, paint was done extremely well - no overspray. The only issue I've seen (or heard) is the sound of "water" running though the heater core - aka...air in the coolant system. However, after driving it for a couple days the sound seems to be gone. Does anyone know if the system self-bleeds? I've heard of vehicles having that type of system but wasn't sure if the suby did. Link to comment Share on other sites More sharing options...
Mr. Sinister Posted November 5, 2008 Share Posted November 5, 2008 All well designed cooling systems 'self bleed'. As long as the cap where coolant is added is the highest point in the cooling system, air will be pushed out into the reservoir. Link to comment Share on other sites More sharing options...
SubieSteve Posted November 5, 2008 Author Share Posted November 5, 2008 When you say "it highest point" are you referring to the radiator cap? I'm not at all insinuating that I don't believe you, but why is it that cars need to be "burped" to purge air when the system should do the job? Link to comment Share on other sites More sharing options...
NutBucket Posted November 5, 2008 Share Posted November 5, 2008 Because large pockets should be bled out manually. As stated, the system can draw more coolant from the overflow but its best to have as much of the air out as possible first. And sometimes a large amount of coolant needs to be added once the system has been "burped". And yes, highest point refers to the radiator cap...or in the case of the LGT, the small tank near the turbo (since there are technically two radiator caps). The air naturally collects at the highest point. Link to comment Share on other sites More sharing options...
SubieSteve Posted November 5, 2008 Author Share Posted November 5, 2008 OK - Makes sense. So I guess the best way to burp the car is to make sure all levels are topped of, park the car on an incline with cool engine, remove rad cap, run engine with heater on until fan kicks on and watch it percolate. Then the remainder of the air will be purged via the system. Does that about cover it? Link to comment Share on other sites More sharing options...
Mr. Sinister Posted November 5, 2008 Share Posted November 5, 2008 OK - Makes sense. So I guess the best way to burp the car is to make sure all levels are topped of, park the car on an incline with cool engine, remove rad cap, run engine with heater on until fan kicks on and watch it percolate. Then the remainder of the air will be purged via the system. Does that about cover it? No need to top it off first. You actually want to take some coolant out after removing the cap when the engine is cool. Otherwise, you will get some overflow as the coolant expands. I'm not sure when the fans kick in, but you want to run the engine until the thermostat opens up. That's usually happens at normal operating temperature. Link to comment Share on other sites More sharing options...
psucaptainkickass Posted November 5, 2008 Share Posted November 5, 2008 I heard the "water" noise for quite some time after replacing my coolant. I just kept filling it up over the course of a week to make sure it was full. My procedure: Drive car all day, in teh morning, open the filler cap, fill. Drive car all day, check coolant reservoir level in the morning...did it drop? If yes, open filler cap, fill. Repeat until the coolant reservoir level stabilizes. Link to comment Share on other sites More sharing options...
Mr. Sinister Posted November 5, 2008 Share Posted November 5, 2008 I heard the "water" noise for quite some time after replacing my coolant. I just kept filling it up over the course of a week to make sure it was full. My procedure: Drive car all day, in teh morning, open the filler cap, fill. Drive car all day, check coolant reservoir level in the morning...did it drop? If yes, open filler cap, fill. Repeat until the coolant reservoir level stabilizes. Yeah, this is the method I prefer over burping if it can be avoided. Link to comment Share on other sites More sharing options...
SubieSteve Posted November 13, 2008 Author Share Posted November 13, 2008 And yes, highest point refers to the radiator cap...or in the case of the LGT, the small tank near the turbo (since there are technically two radiator caps). The air naturally collects at the highest point. Using that rad cap worked! I topped that off, filled the overflow about 2" past full, put the heat on and let it run for about 40 minutes with a couple revs here and there. Yes I had some overflow but it wasn't too bad. This morning I got into the car started it cold took it for a short drive, and no water sounds. Now if I can only get my truck to burp...I'll be set. Thanks for your help! Link to comment Share on other sites More sharing options...
08SpecB_DE Posted March 5, 2016 Share Posted March 5, 2016 Hey guys, I'm having some issues with my system. I replaced my t-belt, water pump and thermostat today. I tried everything I can think of to bleed air out of the system but the bubbles keep flowing and pumping the level up in the resevoir. I can't imagine head gaskets suddenly going bad. I'm very familiar with bleeding systems but this has become a headache! Is it possible my problem is that I believe I accidentally switched the 2 caps? I put the all round cap on the turbo tank and the other on the radiator. I noticed coolant going low in the turbo tank and at the same time the reservoir was filling up. I jacked the right front side up and have done everything I can think of to rectify the issue. Link to comment Share on other sites More sharing options...
Outback2.5XT-05 Posted March 6, 2016 Share Posted March 6, 2016 Hey guys, I'm having some issues with my system. I replaced my t-belt, water pump and thermostat today. I tried everything I can think of to bleed air out of the system but the bubbles keep flowing and pumping the level up in the resevoir. I can't imagine head gaskets suddenly going bad. I'm very familiar with bleeding systems but this has become a headache! Is it possible my problem is that I believe I accidentally switched the 2 caps? I put the all round cap on the turbo tank and the other on the radiator. I noticed coolant going low in the turbo tank and at the same time the reservoir was filling up. I jacked the right front side up and have done everything I can think of to rectify the issue. First, the all-round cap (I think it has the higher rating)goes on the radiator itself. The tabbed and lower rated cap goes on the turbo coolant reservoir. Second, if your system is burped and sealed and you're still getting bubbles in the overflow, you could have a pinhole leak in the head gasket or similar, which is letting air or gasses into the cooling system. A telltale sign of that would be coolant overflow or bubbles in the overflow tank after sustained boost. Good luck Link to comment Share on other sites More sharing options...
08SpecB_DE Posted March 6, 2016 Share Posted March 6, 2016 Okay, thanks. I'll swap the caps and double check for air. We have a tool at work that pulls all the air out of the system but I didn't think I would need it. I switched from the green over to the Subaru blue coolant so hopefully that doesn't have anything to do with it. My car never had a problem before I did the timing belt so there has to be something I didn't do properly. While I'm not ruling out a head gasket, they are bone dry and I never had a coolant consumage issue. Link to comment Share on other sites More sharing options...
Outback2.5XT-05 Posted March 6, 2016 Share Posted March 6, 2016 My car never had a problem before I did the timing belt so there has to be something I didn't do properly. While I'm not ruling out a head gasket, they are bone dry and I never had a coolant consumage issue. Try filling up the rad and turbo reservoir first, swapping the caps and driving a little while, don't be afraid to give it some throttle if your temps are fine. If the caps are reversed the overflow and turbo reservoir might not function as designed. As for the HG's: this is different from a standard N/A HG failure. I had mine fail internally and the leak was tiny and unnoticeable while parked or driving normally. The only sign that something was wrong was an overflowing coolant tank when I would boost on the highway or drive really hard, and bubbles being piped into the overflow when the car was just turned off. Just FYI Link to comment Share on other sites More sharing options...
08SpecB_DE Posted March 6, 2016 Share Posted March 6, 2016 I let the car sit for for about 3 hours, the turbo tank and rad were full, the reservoir was at the min line. I swapped the caps and let it run until it warmed up. I had great heat but I drove it up the street making sure I hit boost a few times and as soon as I pulled into the parking lot I lost heat and my temp gauge was down close to 2 hash marks. I did notice smoke somewhere around the t-stat housing but it's underneath so I'll have to wait until Monday to get it on a lift. Link to comment Share on other sites More sharing options...
Outback2.5XT-05 Posted March 6, 2016 Share Posted March 6, 2016 I let the car sit for for about 3 hours, the turbo tank and rad were full, the reservoir was at the min line. I swapped the caps and let it run until it warmed up. I had great heat but I drove it up the street making sure I hit boost a few times and as soon as I pulled into the parking lot I lost heat and my temp gauge was down close to 2 hash marks. I did notice smoke somewhere around the t-stat housing but it's underneath so I'll have to wait until Monday to get it on a lift. Wait, your temperature went DOWN and you lost heat after driving? How cold was the outside air temp? Link to comment Share on other sites More sharing options...
RckyMtnGT Posted March 6, 2016 Share Posted March 6, 2016 I let the car sit for for about 3 hours, the turbo tank and rad were full, the reservoir was at the min line. I swapped the caps and let it run until it warmed up. I had great heat but I drove it up the street making sure I hit boost a few times and as soon as I pulled into the parking lot I lost heat and my temp gauge was down close to 2 hash marks. I did notice smoke somewhere around the t-stat housing but it's underneath so I'll have to wait until Monday to get it on a lift. yeah that sounds like a big 'ol coolant bubble. Car gets hot enough to boil the coolant since its not under full pressure, then the steam creates an air pocket that the coolant temp sensor cant read, and liquid coolant has a hard time passing by. If you've got a lift and a pressure sucker at work, I'm sure yall have at least one of these floating around. [ame=http://www.amazon.com/Lisle-24610-Spill-Free-Funnel/dp/B001A4EAV0/ref=sr_1_2?ie=UTF8&qid=1457243987&sr=8-2&keywords=coolant+funnel]Amazon.com: Lisle 24610 Spill-Free Funnel: Automotive[/ame] Pop that on and fill it up, then put just the front arms of the lift under the car and lift the nose up a good 2 feet while running the car up to temp. Thats helped on several cars with stubborn coolant burping, mostly Priuses (Prii?) that we have to do water pumps on. Or, start over. Drain it and put the air sucker on there, I use that thing as much as I can when refilling coolant. I used the sucker, followed by the coolant funnel on the turbo reservoir when I replaced my radiator. Even then, the next day after a couple of hot/cold cycles, the overflow had fallen a few inches, so I topped that off once, and it's stayed ever since. Link to comment Share on other sites More sharing options...
08SpecB_DE Posted March 6, 2016 Share Posted March 6, 2016 Wait, your temperature went DOWN and you lost heat after driving? How cold was the outside air temp? It was probably around 40 but outside temp never caused the gauge to fluctuate like that before. Link to comment Share on other sites More sharing options...
08SpecB_DE Posted March 6, 2016 Share Posted March 6, 2016 yeah that sounds like a big 'ol coolant bubble. Car gets hot enough to boil the coolant since its not under full pressure, then the steam creates an air pocket that the coolant temp sensor cant read, and liquid coolant has a hard time passing by. If you've got a lift and a pressure sucker at work, I'm sure yall have at least one of these floating around. Amazon.com: Lisle 24610 Spill-Free Funnel: Automotive Pop that on and fill it up, then put just the front arms of the lift under the car and lift the nose up a good 2 feet while running the car up to temp. Thats helped on several cars with stubborn coolant burping, mostly Priuses (Prii?) that we have to do water pumps on. Or, start over. Drain it and put the air sucker on there, I use that thing as much as I can when refilling coolant. I used the sucker, followed by the coolant funnel on the turbo reservoir when I replaced my radiator. Even then, the next day after a couple of hot/cold cycles, the overflow had fallen a few inches, so I topped that off once, and it's stayed ever since. I'm praying it's just an air pocket. I guess I didn't let it bleed off enough so I'll jack it up outside tomorrow and put my funnel on it and just let it run. I'm still concerned about the smoke I see burning off the exhaust around the t-stat housing so I'll probably pressure test it first. I'm also running Subaru blue coolant right now and I'm down to my last little bit so I don't wanna have to buy 2 more gallons and start over but it looks like I'll have to buy at least 1 more. Link to comment Share on other sites More sharing options...
shadowsports Posted March 6, 2016 Share Posted March 6, 2016 MY-'08 uses green not blue coolant. While I'm sure you can use it, why? I've replaced my coolant every 25k since purchase. I'm 138k now. I don't understand how people get air in their cooling systems? You take the caps off, fill about 1/2 way with 50/50 mix (distilled water). I then fill the turbo reservoir till full and put the cap on. Then finish filling through the Rad. I always remove and clean the overflow tank, then fill it about 1/3 above the full hot line. Then let the car idle until the thermostat opens. Puts me right in between the cold and hot marks. I replaced the radiator a month ago and like every time before, no issues. How do people get massive air bubbles in their cooling system? I don't get it. Link to comment Share on other sites More sharing options...
08SpecB_DE Posted March 6, 2016 Share Posted March 6, 2016 The turbo tank is the highest point so I bled the system through that since bubbles travel to the highest point. I went with the blue because it's a better coolant with the conditioner already mixed it. I also emptied the block so that creates more air than just a radiator. I've bled air from hundreds of cars and never ran into an issue like this so I'm just as stumped as you. Link to comment Share on other sites More sharing options...
shadowsports Posted March 6, 2016 Share Posted March 6, 2016 Probably due to emptying the block then, which I've never needed to do. In this case, you could try using a pressure tester connected to the RAD, with the turbo res open. May need to pinch off the overflow tube as well. Hope you get it figured out Link to comment Share on other sites More sharing options...
08SpecB_DE Posted March 6, 2016 Share Posted March 6, 2016 There's a tool at work to pull a vacuum on cooling systems to get the air out that way so if I pass the pressure test with no leaks I'll hook it up and suck all the air out. Link to comment Share on other sites More sharing options...
coldsoda Posted March 6, 2016 Share Posted March 6, 2016 First, the all-round cap (I think it has the higher rating)goes on the radiator itself. The tabbed and lower rated cap goes on the turbo coolant reservoir. Second, if your system is burped and sealed and you're still getting bubbles in the overflow, you could have a pinhole leak in the head gasket or similar, which is letting air or gasses into the cooling system. A telltale sign of that would be coolant overflow or bubbles in the overflow tank after sustained boost. Good luck just to clarify, this post is correct ^ The coolant reservoir by the turbo should have pressure rating of 108kpa, while the radiator itself has a rating of 137kpa (round cap). You want the top point to have the lower pressure rating as designed. Link to comment Share on other sites More sharing options...
08SpecB_DE Posted March 7, 2016 Share Posted March 7, 2016 Had a small tear in one of the hoses coming off the t-stat housing. Replaced the hose, refilled it, burped the system and all is well again. Link to comment Share on other sites More sharing options...
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