wjones14

My '05 Mustang GT only has 50,000 miles, but the maintenance schedule says the coolant should be changed at 100,000 or 5 years, whatever comes first. I checked the Motorcraft website, where there is a very nice 7-minute video that discusses the cooling system. Yes, it's basically a promo for Motorcraft parts, but it's well done, and the engineers in the video are obviously knowledgeable about the cooling system.

One of the points made in the video was that you should use distilled water with the coolant specified in the owner's manual. The recommended coolant for the '05 GT is Motorcraft Gold Premium.

I don't disagree with using distilled water. In fact I will buy a couple gallons when I change my coolant, just because Motorcraft recommends it. But I just wonder if all dealers and independent mechanics use distilled water when changing coolant?

How many users here use distilled water to mix with the concentrated coolant?

2k7gtcs

I had to replace coolant twice so far. Well once when I changed radiator and then I reused it again when I installed the blower. I could have reused it the first time, but didn't think to do it.

Anyway. I used the premixed 50/50 stuff because I didn't want to put in 2 gallons of coolant and end up putting in 1 gallon of water. I know that's a stupid reason but it made sense at teh time. So if the premix uses distilled then yes I did, if it doesn't then I guess I didn't.

05GT-O.C.D.

I do. On some of the plumbing fittings in my home I have little bits of green buildup, I don't want that stuff getting into my radiator.

Ministang

I always use distilled water to flush the system, and then dilute the coolant to an approximate 50/50 mix. Depending on the car, I usually figure on at least 7-8 gallons of distilled water (most of which I use to flush the system) depending on the car, but it is cheap insurance IMHO, only costs about 80 cents a gallon for distilled water at Walmart. I don't know what a dealership or other garages use, as I always flush my own coolant, and seldom, if ever, have anyone else work on my cars, except for the occasional warranty claim.

825LTRGT

I use distilled water and mix it up when I buy a gallon of antifreeze.

It's cheap and doesn't hurt anything.

MadGT

^ I also use distilled water...

Cusp

I buy coolent premixed. So I can simply pour it in as is. But before that trick, I would do a 50/50 mix with distilled. Cars don't need minerals in their diet.

BrianB

Since we're on this subject, can you damage anything if you use Prestone 50/50 prediluted coolant rather than the recommended Motorocraft Gold?

ravenblack67

Distilled water all of the time.

cdynaco

I never have. Just used my well water out of the hose and never gave it a thought. LOL

Since living here the past 30 yrs I've put a 100k on two vehicles (1 iron, 1 all alum Lotus), plus a lot of miles on some other cars, and have 254k on my '83 F150 (iron-new engine at 215 cause of broken ring). Although I did recore a couple of radiators and I remember seeing some lime build-up inside.

However, I learned the hard way that there's enough calcium/lime in the well water to leave water spots from hell when I wash my Bullitt. The Dealer did an acid wash to remove them. So I have to move fast from keeping fresh water on it until I get each section dry.

So after reading this thread I'll use distilled from now on. Obviously not necessary with the miles I've clocked the past 30 yrs living here, but its cheap and will keep the passages sparklin' clean.

Anthony k

50% of engine builders say use it, 50% say it doesnt matter. i never have and never will. waste of money. people over think stuff. you drink water out of the tap....but its harmfull to alum and steel? do you wash your cars with distilled water?

Ministang

I don't drink water out of my tap, we live out in the country and our well water is very hard. We have a water softener and we also filter it before drinking, but heck, when we lived in the city I ran that water through a filter too, because it had so much chlorine in it. My wife often drinks distilled water too. I don't wash my car with distilled water, but we had a separate spigot installed outside wo I could wash my cars with softened water, and I still sometimes filter it after that, and I sure as heck get the water off my car ASAP when washing, otherwise water spots are a real problem.

Is my water harmful to metals? Heck yeah it is. You should see our plumbing, and how our well water has detiorated it over the years. We've had to replace faucets, our toilet, pipes under the house, etc because of all the corrosion and buildup. No way I'm going to put that stuff in my car straight. Spending an extra $6-8 on distilled water (the anti-freeze costs more than that) when I'm flushing my coolant is a very small price to pay for extra peace of mind on a car I'm planning to keep for many years to come.

davids2toys

Hi Bill,
I just watched that video, I had planned on using distilled water anyway, that to me is a no brainer!
I have reach the 5 year mark and I want to drain all the coolant and replace with new. I bought the distilled water today and tomorrow I am going to buy the overprice motorcraft gold coolant. I am actually thinking of using the prestone kit. Does anybody have a real good proceedure for doing this job? I cant seem to find a lot of info on this
Thanks...Dave

davids2toys

The Ford manual is very vague on this subject!!!

YardSpecial

For years and years. water is too hard. Since when does a radiator need flouride ???

cdynaco

Lots of cavities...

Ministang

WHen I flush/change the coolant in any vehicle, I always use the same method, and no special tools or flushing kit is required. Basically I drain the radiator, refill with distilled water, run the car until the thermostat opens (or remove the t-stat to speed things up if removal is easy enough), let the new diluted mixture circulate for a couple minutes, then shut the car off, wait a few minutes for it to cool down, and drain the radiator again. I repeat this process until the water being drained from the radiator is clear, then I put the required amount of anti-freeze in to reach the proper mixture, and top off with distilled water. It usually takes an hour or two (most of it spent waiting for the coolant to heat up or cool down), and most cars require me to repeat the above step 4-6 times, and I usually go through 5-6 gallons of distilled water.

aston70

I never thought to use distilled water, but probably will from now on.

davids2toys

This is exactly what I was thinking of doing except I have been told that the mustang should never ever be run without the T stat installed

davids2toys

This is something I downloaded from another forum last night. There is some real good info in here

"I recommend checking your cooling system every 6 months. Make sure the upper hose is getting hot and that the radiator fan is turning on. Two major keys of the cooling system. Don’t get me wrong you can’t condemn a hose just by feeling it though. Ford recommends getting your system drained and flushed at every 100k Miles. I flushed mine after installing my supercharger and I always drain it after 30k miles but I would recommend flushing the system at every 100K If possible periodically drain your cooling and change it to ovoid formation of rust and corrosion which can impair (harm) the performance of the cooling system and cause engine damage.
Steps
1. Wait until the engine completely cools before attempting to open the expansion tank cap.
2. Do not mix coolant of different colors. Use Motorcraft Premium Gold, which it’s yellow colored WSS-M97B51-A1
3. Never dump your used antifreeze. (or else I won’t be posting anything) I would recommend taking it to a place where you got your coolant from.
4. Place a large container under the radiator to catch the coolant. (check the hoses, heater hoses and clamps)
5. The drain **** (plug) is towards the left side. Turn it clockwise to open it. If you haven’t opened the expansion tank cap now it’s the time so gravity can take care of the rest.
6. Once the system is completely drained. Remove the thermostat housing from the engine and then reinstall the housing without the thermostat using the old o-rings. Follow the upper hose and you’ll find the thermostat.This will allow the system to be thoroughly flushed and get all the rust left in the heater core.
7. Warning: Do not run the engine while the thermostat is off.
8. Disconnect the upper hose from the radiator and place a garden hose in the upper radiator inlet and flush the system until clear water comes out from the hose outlet. Make sure you collect it with a separate bucket so you avoid a mess dealing with rust.
9. If the radiator has been contaminated or clogged, the garden hose needs to be inserted in the bottom radiator outlet but I would recommend getting a new radiator if severe damaged.
10. Install the thermostat back with a new o-ring and discard of the old one.
11. Second Warning: Never run your engine until the thermostat is installed back to the housing.
12. Close and tighten the radiator drain ****.
13. Have your heater temp. control in the max heat position
14. Slowly add new coolant (50/50 mix of water and antifreeze) to the expansion tank until the level is at the Cold Fill Range mark (CFR).
15. Leave the expansion cap off and turn the engine on until the thermostat opens and the upper hose is going to get hot. Make sure you perform this test in a well vented area.
16. Turn the engine off and let it cool. Add more coolant to the CFR mark in the expansion tank again.
17. Squeeze the upper radiator hose to expel the air and then add more coolant mixture if necessary. I recommend replacing the expansion cap at every 100k miles.
18. Start engine and allow it to reach at a normal temp and check for leaks.
19. This is very important. Set the heater and blower controls to the max settings and check if the heater output from the air ducts is warm because that would be a good indication that all the air has been purged from the cooling system.
20. Always play safe and enjoy.

Bleeding Procedure.
NOTICE: The engine cooling system is filled with Motorcraft Premium Gold Engine Coolant. Mixing coolant types degrades the corrosion protection of Motorcraft Premium Gold Engine Coolant.
NOTICE: Engine coolant provides freeze protection, boil protection, cooling efficiency, and corrosion protection to the engine and cooling components. In order to obtain these protections, the engine coolant must be maintained at the correct concentration and fluid level in the degas bottle.

When adding engine coolant, use a 50/50 mixture of engine coolant and deionized water.

To maintain the integrity of the coolant and the cooling system:
• Add Motorcraft Premium Gold Engine Coolant or equivalent meeting Ford specification WSS-M97B51-A1 (yellow color). Use the same coolant that was drained from the cooling system. Do not mix coolant types.
• Do not add/mix orange-colored Motorcraft Speciality Orange Engine Coolant or equivalent meeting Ford specification WSS-M97B44-D. Mixing coolants may degrade the coolant's corrosion protection.
• Do not add alcohol, methanol, or brine, or any engine coolants mixed with alcohol or methanol antifreeze. These can cause engine damage from overheating or freezing.
• Ford Motor Company does NOT recommend the use of recycled engine coolant in vehicles originally equipped with Motorcraft Premium Gold Engine Coolant since a Ford-approved recycling process is not yet available.
1. Fill the radiator through the degas bottle until the coolant level is between the COOLANT FILL LEVEL marks.
2. Select the maximum heater temperature and blower motor speed settings. Position the control to discharge air at A/C vents in instrument panel.
3. Start the engine and allow to idle. While engine is idling, feel for hot air at A/C vents.
4. NOTICE: If the air discharge remains cool and the Engine Coolant Temperature (ECT) gauge does not move, the engine coolant level is low and must be filled. Stop the engine, allow the engine to cool and fill cooling system. Failure to follow these instructions may result in damage to the engine.
Start the engine and allow it to idle until normal operating temperature is reached. Hot air should discharge from A/C vents. The Engine Coolant Temperature (ECT) gauge should maintain a stabilized reading in the middle of the NORMAL range. The upper radiator hose should feel hot to the touch.
5. Shut the engine off and allow the engine to cool.
6. Check the engine for coolant leaks
7. Check the engine coolant level in the degas bottle and fill as necessary."