[drexplode]

BMW dealers don't use distilled water? Really? Is this common?

[1QuikWS6]

Never knew a dealer of any manufacturer to use distilled water - however, if I replace my own coolant I always do.

Whatever you do - NEVER use Distilled/De-ionized water...

[Red_Bean_Bun]

Distilled water is a cost ......

[BMWs4ever]

Originally Posted by drexplode

BMW dealers don't use distilled water? Really? Is this common?

I called my dealer who said no they don't use distilled water either. That's why I did it myself two years ago. With the electric water pump it is very simple to bleed.

You should serious consider doing it yourself if you plan to keep the car if for a long time.

[rowingone]

Why not deionized water . .it is just water with the impurities removed . .wont hurt anything!

[Miller335]

Doesn't surprise me at this point.

Pretty sad when a weekend wrench turner can do a better job with the details then a high dollar an hour dealership that's been in the biz for awhile.

[Red_Bean_Bun]

Originally Posted by BMWs4ever

I called my dealer who said no they don't use distilled water either. That's why I did it myself two years ago. With the electric water pump it is very simple to bleed.

You should serious consider doing it yourself if you plan to keep the car if for a long time.

So you used the bleed procedure and that's all ?

[1QuikWS6]

Originally Posted by rowingone

Why not deionized water . .it is just water with the impurities removed . .wont hurt anything!

Not so...

Distilled water & De-ionized water are two different animals

Distilled Water
Typically what is easily found in 1gal jugs in grocery stores. You want to run Distilled water in your radiator (and batteries if you have the lead/acid liquid type that can be filled) because it is essentially tap water with all the solid impurities/minerals removed. While some ions related to the solid impurities will be removed in the distillation process; it is still ionized (charged).

If not removed, the minerals can:

• Build up in your cooling system & impair flow over time
• Can be corrosive to internal engine components
• Can cause a more rapid depletion of the anti-corrosion additives found in antifreeze

Typical Distillation process involves boiling tap water & then condensing the steam into another container - leaving all the solid minerals/residue behind.

De-ionized Water
Or 'non-conductive' water, is also a purification process, but not typically found on the shelf at your local grocery store. It involves a different process wherein typically the water is passed thru 1 or 2 columns that are filled with resin beads that remove ions (cations/anions) from the water.

While Distilled/De-ionized water is purer than just Distilled water, DI water is not optimum to run in cooling systems. Because the DI water lacks ions, it wants to 'get the ions back' essentially pulling/disolving/leaching the ions from any adjacent surfaces (such as the metals in your cooling sysyem) - this removal of ions from metal causes corrosion - actually 'eating' the metal.


Metals typically affected include aluminum, copper, & even some grades of stainless steel.

Best way of selecting water to use in your cooling system would be by testing/knowing it's PH value (which is actually related to the ions present in the water). Optimum water to use would have a PH of 7 - which is considered 'neutral'. But selecting water in this way is normally not what the everyday person would do...

In the industry I am in - we employ many different types of cooling systems to remove heat from ultra hi temp reactors/furnaces (400 to 2100 Deg C). At one point, employees were mistakenly filling the cooling reservoirs with DI water from the hi grade system in the Lab - thinking that was best because it was the 'purest'. It only took months to go by before we started noticing numerous leaks at O-ringed interfaces between metal components of the cooling system. When torn down & inspected - the aluminum & stainless surfaces were heavily corroded & eaten away.

Chemists advised not to use DI water for the reasons I stated above - after switching to ONLY Distilled water (and all new metal components) - there has never been another problem...

[drexplode]

Originally Posted by BMWs4ever

I called my dealer who said no they don't use distilled water either. That's why I did it myself two years ago. With the electric water pump it is very simple to bleed.

You should serious consider doing it yourself if you plan to keep the car if for a long time.

SA exact words: "in my 11 yrs of service I have never observed a coolant flush performed with distilled water" This also coming from the guy that stated BMW has life-time coolant. They why does their dealership offer a coolant flush special right now? Hmmm