I am interested in a 96 outback legacy wagon...It is my friends car ...We start the car up and it drives and idles fine then after 10 min of driving the temp gauge rises to about 3/4 and starts to over heat , but i can park the car and with the fans running it stays at 3/4 up on the gauge...so who knows..maybe i will change the thermostat....Also that subaru additive is that only to prevent against failure or will it cure it for a little while..?

it sounds like air needs to be bled out of the system

but a head gasket is likely if they fail to cure it.

It would be nice if it was a thermostat, cracked radiator, hose, cap, or something else like air.

The Subaru goop is for phase 2s and won't help you at all.

I would also check to make sure you have good flow through your radiator by disconnecting it from the system and running water through it from both the lower and upper rad. hose connections.

Also make sure you are not loosing any coolant through leaky water pump, or rad cap that is not sealing the system. This allows coolant to be drawn back into your radiator as the eng. cools down.

This allows coolant to be drawn back into your radiator as the eng. cools down.

 

Is that coolant or air? Can't see any problem with the former....

I figured I may have made that a bit confusing.

If your cooling system is sealed, and operating properly, the coolant will expand into your overflow tank when it heats up, and then be siphoned back into your radiator to keep it full as the antifreeze cools. If your overflow hose is not submerged in coolant, or if your rad. cap doesn't keep the system sealed, the siphoning will not be able to take place and coolant won't be sucked back into your rad. as it should.

Hope that helps.

Thanks for that, makes sense now.

 

So is it now becoming almost fact, that these issues are more at the heart of head gasket and intermittent overheating problem s than the head gasket design itself, if that makes sense as a question?