Thermostat, Air, or Headgasket?

[Sewoolf@ptdprolog.net]

My 91 turbo is having more problems. This is definitely the last repair i am willing to do before i put it to rest.

 

It started overheating thursday night on my way home. I noticed another coolant leak on the turbo coolant reservoir tank which I haven't fixed yet.

 

Here is my problem. I topped off the system several times with coolant while idling with the cap off. The temp gauge is stable at an idle. The fans turn on when it heats up and it looks like the thermostat is opening since I can see the coolant circulate after it heats up. Coolant does burp out of the system intermittently after it gets hot but the temp gauge stays stable.

 

The temp starts going up as soon as I put the cap on the turbo coolant reservoir tank. It just keeps getting hotter and doesn't come back down. Eventually steam starts seeping through the crack in the reservoir tank as it overheats.

 

The radiator doesn't have a cap on this car. It very well could be a head gasket since this isn't the first time it overheated and the car has 220k on it.

 

I plan on fixing the leak and replacing the thermostat. I will not do the HG since the car is nearing its demise anyway. I would also like to replace the cap on the coolant reservoir if i can find one.

 

Is the thermostat located near the water pump behind the hose? Is it an easy repair? What is the best way to get all the air out of the system on this car? Does anyone have a decent Outback for sale, preferably with the 2.2L? Am I on the right track with this?

[Reveeen]

Eventually steam starts seeping through the crack in the reservoir tank as it overheats

 

Cooling systems are designed to be closed systems. It will NEVER work right unless you maintain a closed system (the rad cap, ok, it's not on the rad, but on that reservoir tank, has to be able to pressure the system for correct operation. *Think* of a pressure cooker, water normally boils at 100C, when you pressure a system it raises this 100C to maybe 140C (or more). A properly pressured system flows better.

 

Is the thermostat located near the water pump behind the hose?

 

Follow the lower rad hose to the engine (water pump), under the flange is where the thermostat lives.

 

Is it an easy repair?

 

It depends...........as with ANY thermostat change you really want to avoid breaking the bolts. The other side of this flange is the water pump, so go gently.

 

What is the best way to get all the air out of the system on this car?

 

Mine seems to fill easiest with the nose up on ramps, I have never had to go to extreme measures to get the air out, I hear "stories", but haven't had a problem here.

 

Get your system holding pressure, get it filled, use a OEM thermostat and gasket, providing the rad is ok, and you have no leaks, it should work.