Hey everybody. I'm really hoping somebody can help me. So I bought does not need legacy, and was told of the head gasket needs to be replaced. First thing I noticed there was no coolant in the oil and oil in the coolant. Both were clean and spotless. When I drove the car it drove beautifully! None of the normal signs of a head gasket that I know of from more domestic vehicles. Eventually the temperature will redline. The first time I did this I pulled over right away popped the hood but there was no overheating! I got back him I kept driving. The next time the temperature gage redlined I just kept driving. Within 10 seconds of it redlining the temperature gage would drop back down to normal. It does this over and over again. I do not see any bubbling in the reservoir tank. I replaced the thermostat with an OEM thermostat. But it still has the problem. When the temperature gauge drops from the redline to normal it takes a matter of seconds. One thing I have not done is tried to replace the radiator cap.

Any help on this would be greatly appreciated!

When it overheats, look for bubbles in the overflow tank and check and see if the heat is blowing cold.  These are two signs of HG failure.  HG can hide and usually happen under heavy loads at first.  Are the fans coming on with higher temps?

There's no bubbles in the tank. The temperature coming out of the vents isn't hot but it isn't cold. It obviously gets really hot once the temperature gets up. The fans come on normally.

Lets cross fingers here, and change the Thermostat with one from subaru and replace the cap (and brand name will do). They will need replacing either way so its not wasted money. 

I agree with nipper it sounds like a thermostat problem. 

If the coolant level isn't low the heater core is plugged.

If the coolant level isn't low the heater core is plugged.

 

To add to this you replaced the thermostat.  Did you spend an adequate time bleeding the system?  When you bled the system was the heater on high the whole time?  Did you squeeze the upper heater hose (towards the back of the motor) to  make sure you got the air out of the heater core?

 

To me this sounds like air in the system.

Edited April 29, 201510 yr by lstevens76

I just changed the thermostat today. This morning precisely. I will run it again tomorrow and see if I can bleed the system more but I thought I got it all out. I didn't check the back rad hose. I will be there in the morning. I did not change the rad cap but I will try that too.

was the old t'stat a 'small' one?

With your thermostat was exactly the same as the one from Subaru I put in. When the car is running normally the temperature isn't all that hot coming out of the vents. But eventually it gets really hot once it starts overheating.

1.  are the fans coming on?

2.  when it's running really hot - the cabin heat is hot and STAYS hot for a long time - like minutes?

3.  are there any leaks - is it loosing any fluid?

 

these engines routinely blow headgaskets and they never mix oil and coolant so you need not waste your time checking for that.

 

they blow exhaust gases into the coolant.

a hydrocarbon test kit will verify exhaust gases in the coolant - but initial failures can pass these tests.