If I want to do a thorough job at flushing the Coolant from the system, how much Distilled water should I buy?

I will be running a 35% coolant mix with the rest being Distilled water.

Once the car is completley drained of coolant that will allow me to fill the system with

5.7 liters of distilled water
3.1 lit ires of coolant

I have bought so far a total of 12 litres of distilled water. 3 bottles x 4 liter bottles
I will use about 1 full bottle and a 1.7 liter from the second bottle for the actual fill up and top off. this

To drain out the old coolant should I fill the system with 8.8 liters of distilled water run the car for 3 mins until it gets warm and the thermostat opens up and then redrain it ?

so basically what my question is... Should I buy the extra bottle of distilled water and fill up the car once with just 8 liters of distilled water and let it run for a few mins?

The above calculations was just my thought process please correct me if you guys think its not correct. They are just approximations =)

 

You have already put more thought into it than I would. I'd just make sure you buy plenty. It doesn't hurt to have an extra jug of distilled water around and here in the US it only cost me about $1 for a gallon.

When you drain, I'd see about using something to suck the coolant out of the overflow tank as well. Then fill up with coolant, use a Lisle funnel to fully burp the system, then top it off. I'd drive it that way for a few days to make sure you went through a few heat cycles then drain again and refill with your coolant and distilled water and reburp. Since I'm too lazy to get every bit of coolant out of the system when I drain it, I wouldn't know exactly how much it is going to take to add.

 

What if i drain the old coolant completly...

Then i filled it up with 9 liters or so of distilled water and drove it around for about 3 days.


Would this be ok?

Then i would drain it after the 3 days. Then do my proper mix of 35% coolant and 65% water.

 

Sure, I don't see why not. I'd probably just do it first on one weekend, and then do it again the next weekend. If you wanted, you could even consider using a coolant cleaner during those few days. Prestone makes several kinds.

Maybe you can get some feedback from a real mechanic though, rather than just me. Other folks actually know what they are talking about.

 

Alright thanks for your help

 

Some info.
CoolantFlush

 

Should I drain the coolant from the rad 1st then drain the coolan from the coolant drain plug right on the block ?

or is it best to do them together.

 

doesnt matter, but i would drain the radiator first

 

If i were to fill up my rad mixture with 65% water and 35% coolant, I beleive this would freeze during winter storage... am i right with that logic?

Also, if the coolant does freeze is this ok, if i am not running the car during the winter? And the following summer I allow it to sit in the sun for a few hours before and let it all unthaw?

 

well water expands when it its frozen. probably not a good idea.. could lead to a busted line, block/housing, and/or radiator.

 

+1 You really don't want coolant to freeze inside your engine anywhere. Very bad things can happen. Don't under estimate the expansive force of freezing water.

I'd just get a coolant tester from your local auto parts store. They are cheap and will tell you what the freezing point is of your coolant. Figure out what your absolute lowest winter temps are, and then shoot for 10F degrees colder than that.