S (biochemist) sez:

Water is a solvent.  It will dissolve anything water soluble.  Neither
steel nor aluminum is water soluble.  This notion that distilled water
will corrode your system is a nonsense. In fact, impurities in the
water could well act as oxidizing agents, causing the steel to rust,
and the aluminum to become aliminum oxide.

But in the first place ... the coolant from VW comes already diluted.
Why is anyone mixing anything into it, distilled or otherwise?

B&S
'87 Westy 'Esmerelda Blanc'
SoCal

On Jan 31, 2008, at 3:27 AM, Mike wrote:

> Distilled water has no minerals in it.  Because it's 'wants' to have
> minerals in it, it 'takes' minerals from where ever it can get them;
> that'd
> be the inside of your cooling system.  This is a form of corrosion
> and eats
> away at any thing that it can get it's greedy little claws into.  I
> believe
> that it has been proven to accelerate the breakdown of your engine's
> case
> and heads, gaskets, radiator, heater cores, etc.
> Anyone else familiar with this issue?
>
> Mike B.
>
> ----- Original Message -----
> From: "Rob" <becida@COMCAST.NET>
> To: <vanagon@GERRY.VANAGON.COM>
> Sent: Wednesday, January 30, 2008 11:12 PM
> Subject: Re: distilled water for coolant - was New Car Dealers And
> Parts
> Prices-a service advisors
>
>
>> At  1/30/2008 05:28 PM, Allan Streib wrote:
>>> On Jan 30, 2008, at 7:39 PM, Vdub Guy wrote:
>>>
>>>> I plan to flush my coolant system soon and replace it with VW blue
>>>> coolant and distilled water.
>>>
>>> why distilled?  Is that what VW calls for?  Or is your local water
>>> really extremely hard?
>>>
>>> Allan
>>
>> Distilled water is a known, tap water, who knows? I always use
>> distilled when mixing up coolant.
>>
>>
>>
>> Rob
>> becida@comcast.net
>>