So i have been blindly going about my business for the past couple of days while freezing my but off to finally have a light bulb go off in my head that hey my subaru still has water in it instead of anti-freeze..... Now granted its been leaking coolant from a bad rad plug and maybe head gaskets and thats why its not running anti-freeze since i planned on doing a engine reseal soon.(just got the parts the other day) So i went out and tried starting it and the water pump was frozen in place. Went back out later on in the day and it started up fine and i let it get to normal temp and held it at about 2.5k idle and i noticed no leaks or any water under the car. Now granted i know there were major air pockets in the cooling system since it had been about a week prior since i had filled the cooling system. That being said since there were no leaks and the car ran fine for 1/2 hour is it safe to say that the engine is still safe with no damage from the expanding ice? Or is there other problems that I am unaware of?

You would know by now if it did any damage, but I would keep a eye on it.

Have you put anti-freeze in yet?

Those air pockets may have been what saved it! Besides, that's what freeze plugs are for.

 

If you can't fix it now, and have something else to drive, just drain it all, blow thru the heater hoses to clear the heater core, and the engine, and let it sit untill you can fix it.

Those air pockets may have been what saved it! Besides, that's what freeze plugs are for.

 

If you can't fix it now, and have something else to drive, just drain it all, blow thru the heater hoses to clear the heater core, and the engine, and let it sit untill you can fix it.

 

Freeze plugs? What freeze plugs?

Freeze plugs? What freeze plugs?

 

I must be thinking of a different engine.....

Freeze plugs are only there to remove the sand after the block is poured. Just an urban myth "freeze" plugs are there to prevent the block from cracking.

The only freeze plugs in an EA engine are on the heads, ..........under the valve covers.

 

So if they pop, you won't know it till you're engine overheats........

 

then you add more coolant and wonder "gee....why is it taking 2 gallons to fill this?".........

 

Then you start the engine, run coolant through the bearings, and eventually it hydro locks as the PCV sucks up the sludgy oil/antifreeze mixture.

 

Yeah, So.......I would say you should do an oil change, and check closely for any signs of coolant in the oil.

May be a myth that that's what they are for, but I've seen where they have popped out when the water in the coolant system froze. Not saying your wrong, just saying that's why I said it.

 

Anyways, fix the car and fill with the proper coolant, or you may damage it this winter.