Check the radiator cap. Some cars have one, some cars have two. Change them both and see what happens. If you cannot see green goo or residue anywhere, this is where I'd start.

This assumes the problem did not start after a coolant flush, or part change etc. where the coolant was topped up. If the problem did start after such an event, you need to burp the system better.

 

as mentioned if the problem started after the thermostat change than chances are you still have an air pocket in the system. if the problem was there before the thermostat change and you dont see any leaks anywhere and your not burning it. I would recommend doing a combustion leak test. You are still in the era of the plauged Head gasket issue. How many miles are on the vehicle?

 

I would recommend doing a combustion leak test. You are still in the era of the plauged Head gasket issue.

 

How do I burp the system?
The radiator was flushed and that is when the problem started occuring.
I am going to go to the Subaru dealership tomorrow and get a new oem radiator cap. I'm tired of paying $600 here and there to get the car fixed, and it sure would be nice if it was just the cap!

 

OK that's good news. This is a simple fix and it is inexpensive.

See the following and be careful doing this. The fans can come on any time, and there are spinning belts too:
http://www.clubwrx.net/forums/gener...shooting-accidents/134337898-overheating-after-rad-timing-belt-replacement.html
and
http://www.clubwrx.net/forums/gener...orums/general-maintenance-troubleshooting-accidents/134329337-over-heating.html

Burp the system and, if as you say the problem started after the system was flushed, you should be just fine.

 

The vehicle has 165,000 miles on it, but the engine was rebuilt at 114,000.

 

I burped the system last night getting all of the air bubbles out of the system.
I let the car run for awhile and then took it out on the road, only to have it overheat on me again...

After the car heated up I grabbed the hose coming off of the bottom of the radiator and it was a cool temperature, I also grabbed the hose going into the top
of the radiator and it was only warm. I started to squeeze the bottom hose, and after a few pumps the top hose started getting really hot.
Could the water pump not be cycling fluid through the system?

Some more info:
The heater stopped working on my car after it over heated as well... I don't know if that helps out with any diagnosis...

Thank you guys,

AMarshman

 

You can tell directly if the water pump is not working or if the thermostat is not opening, or in general if you have a circulation problem. This is NOT SAFE to do if you are not VERY careful.

Let the car cool down entirely.

Remove the radiator fill cap.

Turn the motor on, and be CAREFUL of the moving parts. Also keep in mind coolant can gush out at any given time.

Let the car warm up and you may as well burp the system once again, it's set up anyway. Now, just wait. At some point, you should see circulation when the thermostat opens. The level will drop and you will see coolant flow.

When you do, top it off again, cap it, and see if the problem persists. If you never do, even after the fans have cycles on and off several times, then suspect an obstruction, a thermostat, or a water pump.

 

Water pump is definitely working.

Last night I tried burping the system again, and this time I put it up on blocks, on a hill, and let it run for a couple hours, refilling the radiator as needed as air bubbles were released. The heater started to work again after awhile.

Put the cap on, shut the hood, took it out for a test run.

Heater quit working on my again, and the car over heated..

 

is the thermostat in backwards? I don't know if its even possible, but its something to check.

 

Have you pressure tested the system?

 

Yes, the system was pressure tested. The mechanic actually left pressure on the system over night to really test it.

 

If you keep getting bubbles there still may be an air pocket. These cars can be very difficult to bleed all the way. You also may want to check for a blown head gasket. Being that you said this happened directly after a flush it's unlikely, but you never know. The fact that the heat goes out as it's overheating tells me that you still have air in the system and there are only 2 common ways that can happen... not bled enough and compression through the head gasket.

 

I put the car up on blocks, on a hill, took the radiator cap off, and let the engine idle for over 2 hours, adding more water to the system whenever I saw that it was able to take more on. Is there any thing else I could do to bleed the air out?

I had the head gasket's checked when the issue first started and they came back in the clear. I was able to drive the car on two seperate trips without the car over heating, then on a 30 minute drive, it over heated again.
I think I am going to take the car in to a different mechanic to have more diagnostics run on it, It is just nice to kind of know what is going on with it...

Thank you!
-AMarshman