Cooling system question - thermostat?


New member
Hi everyone,

I recently registered on your guys forum, so I am new here.

Wanted to ask you something. I am experiencing constant problems with the cooling system of my 2012 Impreza. First I noticed that it's not cooling down enough according to the temp gauge. I thought that the problem's about thermostat. But a less than 6 months ago I had the thermostat replaced, and then it did not open at all. Now it seems like it opens, but due to some reason the system won't cool down enough and keeps higher than normal temperatures.

Apart of bad thermostat, what may cause this? Maybe coolant went bad or something?

Any ideas are appreciated!




New member
Have got an update on my mysterious cooling system. Yesterday decided to drain the coolant from the radiator, and already broke one drain plug (that's not a big deal, already ordered a new one, but it appeared that the coolant is not green, but brownish.... So I believe the radiator got clogged, and that's why teh coolant flow speed reduced, hense overheating... So I cleaned the radiator and cooling system with water (did not have that cleanser handy) and filled it in with new coolant. Seems like the it won't overheat anymore... So apart of the broken plug, everything works fine.

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New member
Will check it out as well, man. I will check out if there are any error codes, because when I had worn header gasket on my other vehicle (F-150), the error showed up immediately.

Thanks for the idea, man!




New member
A quick update. Checked the error codes yesterday, and nothing showed up. So I guess the problem could be about bad quality coolant or something. Anyways, I am glad it won't overheat anymore.



Subaru Ambassador- AdidaSubarus
Hopefully it won't do it again. But just fyi, no error code will pop up if your headgaskets are worn on this engine. It's a phase 2 2.5, so it usually leaks oil externally out of the head gaskets, and exhaust gas will contaminate the cooling system and cause it to push coolant into the overflow, and often not return to the radiator, hence the overheating. A good way to tell if you do have a head gasket leak, besides visual inspection, is to watch for bubbles in the overflow tank, while the car is running.


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