I bought my 2001 subaru legacy in March from a used dealer. I recently have been running into over heating issues as I am driving. I can be driving for two minutes and the car will go from being at normal temp. to past the H temp straight to the red. I have changed the thermostat and the lower radiator house. I am hoping it is not the head gasket because they had just changed the head gasket right before I purchased the car back in March. I have even tried driving with the heat on and the temp will drop down to normal and than shoot back up. I have allowed the car to cool off and it will jump right back to hot. I don't know what other options I have and I am not going to be a happy camper if its the head gasket! Does anyone have any suggestions or ideas as to what it could be.

Do you have a check engine light on?   Have you checked your coolant level?  Is it a legacy 2.2?  Any visible fluid leaking?

Yes I do have a check engine light on. We got it scanned and it had to do with the O3 heating sensor I believe is what they said. Yes I did we flushed the radiator twice and filled it twice when we replaced the thermosat the first time and the lower radiator hose the second time. To my knowledge there is no visible fluid leaking. Since we changed the two items when you start the car it shakes for a minute and the check engine light starts to flash. I also noticed when I pulled over to let the car cool down I popped the hood and gave it a minute to cool off after a minute I slowly took the radiator cap off to see if it had coolant and as soon as I let some steam out of the radiator the overfill tank started to get bubbles in it. The car was off at the time.

Edited August 28, 201312 yr by Ericas107

So when you got the car scanned the check engine light was ON but not flashing?  Did you use an aftermarket thermostat or a Subaru thermostat?  Its possible that you just have air in your coolant system, I guess these engines are  notorious for trapping air.  I'm struggling with burping the coolant system myself, so hopefully someone else will chime in who can shed more light upon the subject.  If you haven't got it scanned since the check engine light was FLASHING, I would suggest to do so and post the code's here.

2.2 or 2.5 engine?

2.5 engine and no I have not scanned it since the last time. The check engine light only flashes when it shakes than it stops and the check engine light stays on. I believe it was an after market thermostat I bought it from Auto Zone but I made sure it was not the Stant brand because I heard they were no good for Subaru's. I plan on bringing it into a shop on Friday I just will not drive it at all until than.

Make sure it is a OEM subaru thermostat or it will not work, another thing to check for is to make sure you fill the system and that all of the air bubbles are out of the system...Are your radiator and/or AC condenser fins plugged, if so take a garden hose and with little pressure clean them out  

Also are your cooling fans kicking on?? if not follow wires and check the two 20 amp fuses under the hood 

grasshopper, 00 was the last year for the ej22 and that was in the impreza.

99 was the last year for it in the lego.

Make sure it is a OEM subaru thermostat or it will not work, another thing to check for is to make sure you fill the system and that all of the air bubbles are out of the system...Are your radiator and/or AC condenser fins plugged, if so take a garden hose and with little pressure clean them out  

It was not an OEM because there is no subaru dealer in my area but I did go with a failsafe and I had called the subaru dealer to ask them and they said that was a good brand aside from OEM. I am thinking that the air bubbles is my issue. Do you know of a way to get them out? As for my radiator and/or AC condenser fins being plugged im not sure but I will have my boyfriend check for me. My fans do kick on as well. Thank you for your help!

Head gasket head gasket head gasket sorry but why wast your time gessing any bubbles in overflow tank headgasket anytime over 3/4 temp gauge damages headgaskets were the heads planed ?? when gaskets were done. This cerates a problem for me shops do heads without surfacing heads and cupple months later they go agian just this year 12 reheadgasket jobs all same syemtems as yours. The headgasket leaks in the bottom corner of fire ring on #3 cly and 4 cly. Test by running with full coolant syestem no air then with rad cap on hold 3500rpms for about 25 seconds drop rpms and look for bubbles in rad if so headgaskets

It is my head gasket that is causing all these issues for my car. It sucks to say that I have to cough up $2200 out of my own pocket.

Edited September 3, 201312 yr by Ericas107