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Bubbles in the overflow tank?


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Could it be anything besides the HG's? please, please please? :confused:

 

I just changed them (HG'S)a week and a half ago but I DID make that dreaded error of going to 132 FT IBS. before snapping the upper forward head bolt. I went ahead and used that same HG. Is this most likely the cause of my bubbles?

 

Luckily it's on the pssnger side. Should I put yet another new timing belt in when I pull it apart again?

 

My engine does not overheat and never really has as a result of my head gaskets being faulty.

Help!! Thanks.

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Bubbles are never a good thing.

 

 

In case you don't know, the bubbles are caused by exhaust gas leaking through the bad head gasket, then entering the cooling system. The build up of hot gas vapor causes the engine to over heat. At first a small amount of gas vapor may not be enough to cause over heating. However, with time it will only get worse.

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I got confused and posted this elsewhere but have you had the coolant checked for combustion gases? I would try that before tearing it apart again.

http://www.ultimatesubaru.org/forum/showthread.php?t=117971&page=2

 

I have not checked for gases. I did not totally flush my coolant system so could there be comb. gases left over from before the HG job?

 

What ELSE, if anything, causes bubbles?

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So i couldn't find the bubbles when I went 6 miles at lunch today. When I drove 11 miles home fro work--there were a very few bubbles. So it really has to warm up to bubble a little. Gonna take it for a 40 minute highway test tomorrow to see what that does. Don't know if I should delay the inevitable or re-do that HG while the procedure is still fresh in my pea brain.

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45 minutes is my magic time.

 

After you overhead it - let it cool down. Add coolant (which will only be so successful) and don't overheat it any more on the way back home. These are a PITA to burp so it's hard along the road. You could try filling through the top hose then topping off the rad after it's cooled off along the road. May help, certainly won't hurt.

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I believe you can get bubbles by not bleeding the air out of the the coolant system but this might not be your case since you didn't completly drain it. I know that my shop here in town did the combustion gas test for free but that might be because he had dollar signs in his eyes as he knows I only take my cars there...

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I went about 50 miles after work averaging 72 mpr and then peered into the overflow tank for a good minute and saw no bubbles. My temp needle was where it usually is,underscoring the ball on the thermometer, not quite to 9 oclock. No hint of overheating.

I've put about 500 miles on it since the HG job. Hoping the coolant system is still burping it's PITA self and accounting for a bubble here and there.? Is there a way to make sure all the air out?

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It is not a PITA, it was just done wrong.

 

Every car this is valid for EVERY car made.

 

Fill radiator SLOWLY. on level ground

Start car up with cap off.

Wait for T-stat to open (surge at radiator neck)

Once that goes away, top off SLOWLY

Replace cap

Fill the overflow tank.

Go for a short drive

Let car cool down

 

Repeat above. If you have to do it more then once something is up.

 

BTW get a new cap.

 

People and shops don't do this right as it takes time or they never learned how.

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i think, if subaru had put the rad cap on the passenger side of the radiator where the top radiator hose is located, i think there would be fewer problem. but you still would have to fill it slowly.

 

the last time i did it i used a 3/8'' tube and i siphoned the coolant out of the jug which was sitting on the passenger strut tower into the radiator. this process was so slow, it think it gave the coolant time to ''flow'' down into the engine with out bubbling over.

 

anyway, i think filling slowly is one key part of the process.

 

FWIW

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I think I'm in the clear. When I cleaned the overflow tank last weekend, I put the coolant to the cold line. Since then, when the car is cold, the level is exactly on that line. When it's hot the level is about half way up to the max/hot line. The bubbles are gone, at least for now. I've been searching for them for days( i'll be shopping for a hood unlatch cable if i keep it up) and haven't found a one.:grin: Thanks, folks!

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