Flushing cooling system in single degree temps

I am in the process of flushing coolant in a 3.8L NA GP, getting rid of the orange dex-cool and changing over to long life green coolant. I have preformed this process in the past in other 3800's with no issues. To be sure all the original dexcool is out of the cooling system, I use the Prestone Super radiator flush and then I drain the system and put in plain water, drive , drain, repeat, etc.
I started this process and now the air temperature has dropped down to zero (I love PA)
How long would I be able to park the car outside before the water freezes and cracks the radiator and block and causes other issues?
I need to drive tonight (about 35 miles) and shut off the engine and leave the car for about 2 1/2 hours.
Would I be safe doing so?
How long before water will freeze?
After the trip, I will be bringing the car home and parking it in a heated garage, so freeze up will not be an issue then.
Probably tomorrow, I will drain the water out of the car and put in new long life coolant.
Tell me if you think this is ill advised.

why not put some antifreeze in there. id not take that chance. drain the rad at walmart, then dump one whole gallon of straight green in there, it will mix for you on the drive.

I thought about that. Even 1/2 gallon of coolant will lower the freeze point of the cooling system. I just don't want to mess around trying to drain the water from the radiator by removing the lower hose while so dark and cold out. I may just add some coolant to the radiator before I leave, just top be certain. I just wanted someone to chime in on this and tell me if it is worth the risk. Thanks Scottydoggs.
BTW, do you know Steven Banom? He is from NJ also.

With these cold of temps, pure water in the rad would freeze is 1-2 hours easy. The rad would prolly split first as the engine block will stay wamer for many hours after shut down but you'd still be pushing it.

Definitely don't do it.

Maybe have a buddy chill in the car and run it every half hour?

Keep it simple and put dexcool back in...nothing wrong with dexcool.

NotEnoughGPs said:

I thought about that. Even 1/2 gallon of coolant will lower the freeze point of the cooling system. I just don't want to mess around trying to drain the water from the radiator by removing the lower hose while so dark and cold out. I may just add some coolant to the radiator before I leave, just top be certain. I just wanted someone to chime in on this and tell me if it is worth the risk. Thanks Scottydoggs.
BTW, do you know Steven Banom? He is from NJ also.

Click to expand...

dont know steve lol nj maybe small but its not that small...

get some type coolant in it or it will be trouble cant do just water to cold

I'm reading this.. and here's how the first post came across.

Been living in PA for most of my life.
Damn... the weather here just magically got colder than it's ever been.
OMG... can someone with a science degree tell me how fast water will freeze

Sorry...I got a chuckle out of it.. sucks for sure and I'd appreciate you stop sending us this cold crap. Get some kind of antifreeze in there asap. It's not worth the risk.

I know it's not best time of year to be flushing a cooling system. Well, anyways, I will be draining the system and adding coolant later today.

BillBoost37 said:

I'm reading this.. and here's how the first post came across.

Been living in PA for most of my life.
Damn... the weather here just magically got colder than it's ever been.
OMG... can someone with a science degree tell me how fast water will freeze

Sorry...I got a chuckle out of it.. sucks for sure and I'd appreciate you stop sending us this cold crap. Get some kind of antifreeze in there asap. It's not worth the risk.

Click to expand...

Exactly everything I thought.

I hope that car isn't sitting outside right now.

Not sure why you choose this time of the year to do this, it couldn't have waited like 2-3 months? If the car was working and working well, why mess with it, now you've created a situation that isn't good and could cause damage. Not trying to be mean, but I know schedules are busy, but there really is better times to do this stuff.

I'm with everybody; park it or put coolant in it.

Years ago I was at my buddys cabin for the weekend. -10 to -20* C was the average temp. When we went to leave, one of the cars had a bad coolant mix, and when we removed the rad cap, it looked like a lime slurpee. Luckily the car fired right up and all was well.

Oh, and we also lost a can of 7-up; it exploded in one of the trucks over night and left 7-up icicles on the roof. LOL

LOL. Reminds me of stories on car forum pages from years past.
Don't remember who it was, but they did not have a garage to work in, and they started a engine replacement job in the driveway in the evenings. Then, a large snow storm hit.
They said they spent most of their time with heat guns trying to melt snow around the engine and under hood area. They eventually gave up and covered everything and left the project for better weather.
Also, they said they had no power tools. Whew!