So... Antifreeze is really important in the winter...

[5whiskey]

Yeah, so I do have my moments of semi-intelligence but then at times I can be pretty dense. I just bought my Ex a few months ago and replaced the thermostat shortly after. I didn't put any antifreeze in, just tap water. I didn't lose a lot of coolant, probably about 1/3 of a gallon. Apparently I lost enough that the antifreeze mix isn't stable down to 10 degrees. Coolant froze in the radiator as I started to get up to speed.

It overheated and I had to pull over and let it cool on my morning commute. I added some antifreeze for the evening commute and all was well. No leaks that I see, but to be fair I haven't crawled under and in it. I did let it idle for about 15 minutes tonight to see if I could find any leaks. None... then I drove it down the road a couple of miles and still no sign of leaks. I know Fords have their problems but I will swear by my Ex if I don't have to do a repair because of this.

Remember boys and girls: Antifreeze is your friend. I'm going to get that tattooed on me if I have to tear into (or worse replace) the engine.:roll:

 

[Sock Puppet]

You got lucky. Go buy an antifreeze tester, or have a test done, to find out your freeze threshold. Cheap and easy and could save you a lot of heartburn.

 

[Number4]

Got in my Ex yesterday morning, temp outside of car was 9 degrees, engine itself was 17.

 

[IPcamper]

Be glad you don't live farther north, Had an old ford tractor crack a block on a night that dropped to -5. I keep a jug of 50/50 antifreeze mix in the garage for topping off after repairs, that way I don't have to worry about remembering it.

 

[Number4]

Up in the North, during winter, you could probably get away with running straight antifreeze.

 

[2Trux]

Up in the North, during winter, you could probably get away with running straight antifreeze.

The freeze point of ethylene glycol antifreeze starts to go back up once you get past a 70/30 mix. At 100% antifreeze the temp is back up to -5 F which is the same as a 35/65 mix.

(EG is ethylene glycol, PG is propylene glycol):

 

[Number4]

The freeze point of ethylene glycol antifreeze starts to go back up once you get past a 70/30 mix. At 100% antifreeze the temp is back up to -5 F which is the same as a 35/65 mix.

(EG is ethylene glycol, PG is propylene glycol):

Hmmmm, IDK, if you look at the down trend for the EG, it's on a curve. The up trend isn't curved. IMO, the down trend happened too fast and the up trend is simply the blue line ricocheting.

 

[lincolnshibuya]

well, that's what freeze plugs are for.

 

[mikeinri]

Captain Obvious says... Even if you don't have leak at this point, you should still drain the system and replace it with the proper mix.

Mike

 

[5whiskey]

Captain Obvious says... Even if you don't have leak at this point, you should still drain the system and replace it with the proper mix.

^Oh fear not, I did. No leaks that I can see, no smell of coolant in the exhaust, fluid doesn't disappear. I got stupid lucky I suppose.

 

[mikeinri]

Lucky is good!

Mike

 

[Jim_WY]

You also need to look at the curves for heat transfer efficiency of antifreeze mixtures. There's a very good reason why a 50/50 mix of antifreeze to water is generally recommended.

The OP did get lucky, but it stands to reason that the radiator would slush up before the block froze.

 

[5whiskey]

The OP did get lucky, but it stands to reason that the radiator would slush up before the block froze.

This is exactly what I believed happened. I started my truck and let it idle for a couple of minutes before taking my girl to school. When we got in the heat was starting to get lukewarm (meaning water was circulating). A couple of minutes after I hit 55, heat went ice cold. I kept driving, thinking maybe the vacuum line came off of the valve. I dropped her off and started driving back, still cold air. After a couple of miles the engine temp started to spike. So I started out with liquid coolant when I backed out of the driveway. Road speeds ended that fast. Maybe an evaporative cooling effect of the radiator??? Either way God loves me, I got lucky, and I have now learned the lesson of ALWAYS keeping a check on coolant levels/concentrations.

 

[n2audio]

well, that's what freeze plugs are for.

Actually, it's not.
They're core plugs that are required to cast the block.
The fact that they CAN in SOME cases relieve pressure in a freeze is just a coincidence.
In a lot of cases they don't pop, and in others they do pop and the block is still damaged.
Counting on them to protect the engine in a freeze is not wise.

 

[swshawaii]

^ Fact, and very important to know.

No manufacturer has come forward and stated that the holes in the side of any engine block are there for freeze protection. It is possible and even likely, that freezing water will push a core plug out. If the water doesn't freeze solid it is possible that there will be no damage to the block, but in most cases of a "hard freeze", the water jackets in the block will be cracked as well.

http://en.wikipedia.org/wiki/Core_plug#Freeze_plug_myth