Hi all,

I have a 2002 Mini Cooper S and I have decided to change the coolant as it was last changed in 2007. I intend getting the oem BMW Mini antifreeze but I would like to hear from you folks on this forum about which water should I use to mix with the antifreeze because after trawling the net to see what water is recommended I am none the wiser (actually, I am more confused after having done that as I have found conflicting posts for each and every type of water ! )

The contenders that I've seen on the net are distilled water, RO (reverse osmosis) water, bottled drinking water and deionized water (tap water being the one which was the least recommended). Could you please tell me which water is the best to use to make a coolant mix for my Cooper S?

Tx in advance

 

I make my own variation of distilled water. I use the water recovered from my dehumidifier, then run it through a funnel with a coffee filter, and bottle it until needed. If you have central AC, you can just catch the water that comes out of the drain hose. Mine ends outside along the condenser pipes, but I'd just reroute the hose from the little pump if I didn't use the dehumidifier.

Any water will work to cool the engine. But any minerals or other impurities in the water can eventually coat the inside of the system like plaque, reducing effectiveness over time. I'm betting it's not the best for the waterpump, either.

 

as it is an english car, you must order english water

see e-bay

.....

you would probably like water with fewer impurities so get some local bottled drinking water. It is only a wee bit better filtered than the tap, but 95% as good as your local Danasi

(If 20 years ago I could see what a SAP would pay for 'filtered' water!!!!)

 

Mineral free water...so distilled is best....
SPRING WATER OR BOTTLED DRINKING WATER is worse than tap water mineral wise in most areas...minerals are added to improve the taste of regular tap or spring water...so that should be avoided.. so distilled is best, but in most area clean tap water is ok.

 

Ok Blackbomber, tx a bunch, so you are going with distilled water...let's see what other replies we'll get...I hope it won't get as confusing as all the other non-Mini related sites that I've been on for the past 3 to 4hrs... Hey and tx to capt bj and ZippyNH for your posts too which I've just noticed as I was replying to Blackbomber...tx to you all for your prompt responses...much appreciated.

 

Rememer...it is the disloved impurities in the water that remain after a bit is boiled away that is the problem....any filtered water removes chunks..like tap....but the disloved minerals such as salts, manganese, sulpher, etc is the issue.

 

I agree with your logic but like I said, I've seen so much conflicting info which is confusing me. For example, this is what is stated on a TSB for AMSOIL Dominator coolant boost as the water to be used to be mixed with this product:



My brother recommends that I use my own domestic RO water...

 

I think if they make the requirements too stringent, it might hurt sales. Everyone knows where to buy bottled water.

 

Blackbomber, some more from that TSB (and this was for their product which is specifically for aluminum radiators...like our Mini's one, right?):

[FONT=HelveticaLT][SIZE=2][FONT=HelveticaLT][SIZE=2]does not remove chloride.
[/SIZE][/FONT][/SIZE][/FONT]

 

Another relevant question : what type of water is used in premixed coolants ?

 

Distilled, de-ionized, and reverse osmosis water should all be fine.
Water from a water softener device will actually have quite a lot of
chloride since all the magnesium and calciums salts are exchanged
for sodium chloride!

 

Tx Cristo !

 

Just to make it more complicated...most/many municipal water supplies have stopped using chlorine in the past few years due to water rules...the end products of chlorine acting are kinda hazerdous, so these end products are an issue....
some things do not need to be overthought....99% of shops that do not use premix antifreeze use tap water....
In this case you have best case, distilled water, and then various filtered types, but remember...bottles reverse osmosis water has had salts and minerals added to it for taste...so kinda deferes the purpose...
Drink a glass of distilled water...yuk...(due to total lack of ANYTHING OTHER THAN H2O).
Dissani..read the label...has been purified, but then most of the minerals added back....much more expensive than buying a jug of distilled water for $1.50 a gallon too....

 

Also antfreeze does have chemicals and addatives to help keep the minerals in solution, and lubercate water pump seals....the anticorosive propties are kinda important...pure distilled water is VERY active as a corosive..(it is totaly and chemical free, all bonds are open and ready to function on a chemical level)....but very few folks run pure water..hense the reccomendiation against pure distilled water in the VERY FEW RACING APPLICATIONS THAT REQUIRE ONLY Water be used...many tracks prohibit antfreze such as glycols due to the slickness...and many folks that buy almumum rads use them in this type of application...
The fear of excess chlorine is kinda overblown...basic metalugly is aluminium creates a oxide coating on the surface that protects the inner metals....i suspect the levels can cause issues are unusual in typical water supplies...but as i stated earlier, many water producers have moved away from chlorine in the past 10 years....so that becomes a non argument....

 

Tx for all your posts ! High chlorine content in our water here in Malta (Europe) is a big issue. Apart from distilled water what is your opinion if I use RO water from my own domestic RO unit...that's not like bottled mineral water, right ? (i.e. the industrial/commercial RO water with minerals added to make it taste good as drinking water for retail sale in bottles)...based on all that I'm seeing on these forum posts, I need to decide if to use distilled water or my own RO water to mix with the BMW Mini coolant. Your comments about using RO water from my own domestic RO unit would be greatly appreciated.

 

Either one is fine...heck based upon all arguments, just different degrees of good. Mataining it once it is installed (montioring for levels, quality, and changing it as required) will have much of of an impact than the choice of the two water scources listed...
You will not be able to tell the differeance in any meaningful way, especially in a car several years old.

 

Ok Tx. The head on my friend 2003's MCS went and I'm pretty sure it was a failure related to a wrong coolant type and so I'm trying to be sure that I put in the right stuff into mine to avoid that nightmare scenario

 

Usually at the auto parts store you go to, they will have gallon jugs of distilled water right beside the antifreeze

 

Distilled water. $1 a bottle at grocery store. Mini system is 6 liters for a full flush.

 

Tx HochSpannung and Blaxin41 !!

 

If this has not been drilled into your head yet. Distilled water and distilled water only for mixing with antifreeze. There is nothing better.

I have seen people running 100% antifreeze, that is crazy. Water has better specific heat value than the pure antifreeze that it carries more heat.

Main media for carrying the heat away should be water. If possible we all should be running H20 only but since water corrodes metal and freezes, thus we put coolant/antifreeze to protect engine from corrosion and splitting in half when water freezes and expands.

Mineral precipitate out of the solution will be stuck in the radiator and heater core and different crevices in the engine coolant channel. Guess where the heat will be building up. You may get hot spots in the engine and cause bad things to happen.

Distilled water is cheap enough considering how much your Mini is worth. It is probably the cheapest part for your vehicle. I wouldn't be cheap with it.

 

I use water from my tap, always have. My water is from a well 400 ft below my house. I figure if i drink it it will work in my car.

 

Well, I don't know what to tell you.

Mineral adds to the taste of the water believe it or not.

Even small professional irons that are used in dry cleaners use mineral filter because those machines cost more than many many car radiators.



That radiator will cool the coolant because heat flow from more to less. How efficiently it will cool? I don't know. I don't want to find out and distilled water is just too dang cheap to pass when I am pumping near $4/gal every 2 weeks and all I need is $3 for the whole year maybe less. Besides, I wouldn't want to see that in my engine.

Mineral contents in water will vary with different area of the country; I really don't mind/care anyone putting tap water into their radiator/engine. Just wanted to share the importance of distilled water for the well being of the vehicle, that is all.

Just my 2 cents.

 

Interesting premise. When's the last time your internal temperature went to 240 degrees? As DDMini said, mineral content is different depending where you live, but given the muck on my shower curtain I'd never even consider using tap water in my car. Distilled. Cheap and easy.

 

Tap water. While distilled water is better, it won't matter unless you keep the car forever.