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Radiator Overflow

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97 2.5 Outback DOHC

Fans work, thermostat seems to function. The fan/fans kick in and the thermostat opens drawing fluid into rad.

 

The problem is that the overflow bottle overflows while driving and gradually the system loses coolant.

 

I have flushed the rad, bought a new Subarau rad cap, also open the system to allow air to escape to prevent an airlock.

 

Please tell me this is not a head gasket or combustion problem...

 

Mike

exact same thing mine was doing.. ended up being a cracked block, had to swap the motor

 

 

 

97 2.5 Outback DOHC

Fans work, thermostat seems to function. The fan/fans kick in and the thermostat opens drawing fluid into rad.

 

The problem is that the overflow bottle overflows while driving and gradually the system loses coolant.

 

I have flushed the rad, bought a new Subarau rad cap, also open the system to allow air to escape to prevent an airlock.

 

Please tell me this is not a head gasket or combustion problem...

 

Mike

Make sure that the hose connecting the rad to the coolant expansion bottle is in good shape. No leaks.

 

Any bubbles, or oily skum in the coolant expansion bottle?

 

Commuter

probe, when you squeeze the top hose, is the system building pressure?

Try replacing the radiator cap; not only does it open to allow coolent out of the rad into the overflow tank, but it also needs to open to suck coolent back into the radiator when the engine cools down. There are actually two valves in your cap to allow back and forth flow depending on temperature.

Take the raditor cap off the car when its cold. Let the car run and se if there are any bubbles in the coolant. If there is you have a blown headgasket or worse cracked block. I would vote for headgasket.

 

 

nipper

Well, if you already fitted the new cap, then yes, it sounds like a bad headgasket :-(

Is your antifreeze topped off in both the radiator and the overflow tank?

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