Coolant Froze...what to do next

I've read all related posts; looking for any additional information specific to my case.

99 XJ I6 AW4

While out of town on training I suspect that the coolant froze over. Temperatures were quite cold, dropping to -37 degrees celcius (without windchill). Here are the details I received from the wifey, while away:

-"no start, just goes click"
-Jeep starts, using dual battery and driven 1-2mile trip, max speed 30mph...
-"stalled twice at stop signs around town...Flipped it to backup battery and it started again"
-"came straight home and let it idle for a bit" (d'oh!!!...women!!!)
-"came outside after 20min and it had shut off/stalled"..."there was steam or smoke coming out around the hood, and when popped seemed to be from front the drivers side of the engine"
-after intense questioning, she states that at no time did the engine make any unusual noises, like knocking. etc.
-When I looked at it this morning I notice trace coolant around block heater/freeze plug at front driver's side of block, on electric fan and under dual battery (oem airbox location).
-oil checks fine, exhaust fine
-coolant is clean but 3 liters low...topped up
-ran jeep at idle for 20min or so with no apparent problems, oil pressure fine, no oil or coolant leaks.

I plan to double check the freeze point tomorrow and flush coolant if necessary. Also, I'm going to clean up around that front freeze plug and see if it is still leaking. Would this one be a beotch to change out? The only thing I can guess is that I mixed up straight antifreeze for 50/50 mix. Did I get really lucky here or what?
TIA

Darren

check for leak external and internal, and drive it and see how it works.

Usually the freeze plugs pop out as the coolant expands. I had a 65 ford falcon 6 freeze on me but not too badly. I started it up and let it idle for about 20 min with the radiator blocked and a blanket over the hood. Once the rad was liquid I drained out the water from the drain valve and replaced it with a gallon of 100% anti-freeze [I had 100% water in it], kept at it in 20 min increments for about 3 hours, then it started circulating, the heater core was the hardest part, that unfroze last and had to be replaced, also had to replace one freeze plug that had pushed out, was easy on the ford, they were on the opposite side of the exhaust.

Use a 70/30 mixture in cold climates (70% antifreeze, 30% distilled water)

Blaine B. said:

Use a 70/30 mixture in cold climates (70% antifreeze, 30% distilled water)

Click to expand...

Yeah, staight antifreeze will turn to a hard slush about 10*F. http://www.gi.alaska.edu/ScienceForum/ASF6/680.html

How come my rating is -38 degrees according to the Prestone checker then?

Careful about starting any engine that may have frozen. A water pump frozen hard can.
Slip belt until burnt.
Jump belt off pulley
Twist shaft off
Twist impeller off of shaft.
Rip seal as ice break up.
Engine can overheat before rad melts out and blow coolant. This don't happen often but in extreme cold it will.

I'd go ahead and pull the pump to check it. Depending on your mileage it mgiht be good to replace anyway.......or atleast, the gasket.

I'm surprised nobody's mentioned adding a block heater, particularly in -37degC temperatures. Jeepsareus has them for $33 here, and they're cheap protection against frozen coolant and molasses-consistency oil. The battery blanket (also $33) may not be a bad idea, either.

FWIW, I ran into a similar problem about six years ago with a rented Ford Fiesta I was driving while visiting my parents. Didn't get as cold there (-18degC), but it did get cold enough to pop the freeze plugs out. First clue: the gradually-melting inch-and-a-half diameter green popsicle-looking things I spotted under the engine walking out to the car in the morning...

Thanks for replys.

After doing some figuring I think my ratio was 65 water to 35 coolant. I have it at 70/30 now and it tests to -46 celcius or thereabouts.

There definately was a leak at the front freeze plug, it also doubles as a block heater (see pic below). I added a can of that Barr's stop leak with the new coolant to hopefully take care of it. It is barely moist on one spot of the plug after a good 40min hard drive around town (I may just not have dried all the old coolant off of it. The only thing that worries me is that this freeze plug slightly sits out, i.e., it is not flush as the other plugs are...how normal is this??? I just want to make it through a couple months to some warmer temperatures and I will change it out...I think I can get in there pretty easy...maybe just remove the power steering support bracket.

Everything else seems fine, I definately dodged a bullet here.

Darren.

any idea how much current a block heater draws? I'm not worried about freezing the coolant, but sometimes it sure would be nice to have the engine pre-warmed, but if it's gonna cost $50/month on the electric bill I'll forget it.

OEM Engine Block Heater.
2.5 L 4-Cylinder Engine: 115 Volts 400 Watts
4.0 L 6-Cylinder Engine: 120 Volts 600 Watts

Don't use stop leak......it may clog up or sludge your heater core, and that's no good....

Any why not use the 4.0 block heater ont he 2.5 to make it extra toasty?

Blaine B. said:

Any why not use the 4.0 block heater ont he 2.5 to make it extra toasty?

Click to expand...

Two reasons:

- It may not fit. I'm not very familiar with the 2.5-litre engines, but the 4.0 likely uses larger-diameter freeze plugs. Also, the 4.0 may use a larger heating element that won't fit into a 2.5's water passages.

- Too much heat is bad. You could end up boiling the coolant if left on for too long. Not very likely, but it has been known to happen.

Oh, and one quick note: if you're in weather cold enough to require a block heater, be sure to leave the heater set to full heat when you switch off.

==================
-37 degrees celcius
===================
What is that in American?

===========================
but sometimes it sure would be nice to have the engine pre-warmed, but if it's gonna cost $50/month on the electric bill I'll forget it.
============================
If you want it to be warm at the same time each day like in the morning. Use a timer set to come on 2/3 hours before leaving for work or were ever. That should take the chill off the engine. Without costing an arm and a leg.

badron said:

==================
-37 degrees celcius
===================
What is that in American?

Click to expand...

-37 degrees Celsius. Metric measurements have been legal for use in government, trade, and commerce in the U.S. since the signing into law of the Metric Act of 1866.

But in Fahrenheit, it's -34.6 degrees. -40degC and -40degF are the same, in case you're wondering where the graphs cross.

badron said:

If you want it to be warm at the same time each day like in the morning. Use a timer set to come on 2/3 hours before leaving for work or were ever. That should take the chill off the engine. Without costing an arm and a leg.

Click to expand...

hmm... i like that idea.

I'd think someoune who lived where it gets that cold would learn to be really careful about the coolant mix.
Anyway a note on coolant testers -- they will only tell you if you have too little antifreeze. The floating balls dont know about the magic 60/40 point and will tell you you are good to -50 or something on straight antifreeze.

Blaine B. said:

Don't use stop leak......it may clog up or sludge your heater core, and that's no good....

Click to expand...

Not to mention eveything else related to the cooling system....

600 watts is like 6 one hundred watt light bulbs, or half a blow dryer. Not a $50 dollar a month item. Especially compared to tow rates.

Watch the capacity of the extension cord and length, plus the circuit you plug it in to, if you go block heater. Long small gauge cords lose power and overheat; the circuit shouldn't have much else on it.