new to this board... any help would be appreciated... 91 subaru legacy (recent purchase) has been leaking coolant out of the reservoir. temp guage says temp is ok. happened three times in the last week. each time i refill radiator and a day or two later it backs up into the reservoir and leaks out. temp guage seems to work. only noticed it getting close to too hot once- the morning after it first happened, before i refilled the system. since then it goes to just below halfway.

what could cause this to system to back-up like this? the check engine light also goes on and off, seemingly in no relation to the overflow times. any ideas ?

Did you bleed the radiator when you refilled it ? the bleeder should be on the left side of the radiator at the top (looking from the front ) the are known for erratic behavoir if they arent bled. and your cap may be past its use by date.The temp gauge should not move once the car has warmed up, thats how i know something is wrong with mine if the gauge is up at all from the normal spot there is something a miss and i check why :-\

Thank You. I replaced the radiator cap yesterday and didn't know about the bleeding thing. I will get on that today.

This sounds like the way my EJ22 behaved when the head gasket was leaking.

 

Bleed on a slight incline with the front of the car highest. Idle until fluid rises in the radiator. Then switch off the engine and usually there a little air will be burped out. Wait 15 min, idle again, fluid rises, screw in the bleeder screw and rad cap.

 

You can go far with a leaky head gasket if you keep an eye on the coolant level, but a repair is of course best.