First Out of Warranty Maintenance -Advice?

[rufusdedog]

My warranty expired this month so I thought I would take care of maintenance things that aren't covered by BMW (or not very effectively). I have 35 K on the X5. I changed the air filter and spark plugs myself, and had the dealer change the coolant. It was a busy day at the dealer (Saturday appt) and I asked the SA if they used deionized or distilled water to mix with the coolant. He said he would check. Well, about 2 hours later, he told me the flush was complete and they use tap water to mix with the coolant. A conversation with the tech confirmed this. My question is- is this standard practice at the dealer? Will this cause any problems down the road?

[JCL]

Originally Posted by rufusdedog

..the flush was complete and they used tap water to mix with the coolant. A conversation with the tech confirmed this. My question is - is this standard practice at the dealer? Will this cause any problems down the road?

It depends entirely on the quality of the tap water. Around here, our water is very soft, and is fine for both cooling systems and batteries. In some locales with hard water, with lots of minerals in it, using tap water can cause problems. So, how is your city water quality? Do you have to use a water softener at your house so that the water doesn't damage your household plumbing? That would be a good indication that it is too hard.

If it is standard practice to use tap water at the dealership, it suggests that the water is probably fine.

[ard]

Unacceptable to me! Unless they have a water cert on the tap water.

I do not have a BMW service manual, but I am willing to bet that they specify distilled water....

I am not one that ascribes to the 'dealer knows best' theory.

A

[JCL]

Well, actually they don't require distilled water (unless they changed it in the past few years, as this BMW technical document is from 2007). I highlighted the water requirements, as the antifreeze requirements in the full document (below) aren't really part of this question.

.....However, it is not only necessary to comply with the mixture ratio specified; the minimum requirements for the quality of the water must also be adhered to:

• Appearance: colourless, clear
• Sediment, without suspended matter
• pH value: 6.5-8.0
• Total hardness, max.: 20° dH (German hardness grade) or in new measuring unit:
• Total hardness, max.: 3.6 mmol Ca 2+/ ltr.
• Chloride content: max. 100 mg/ltr.
• Sulphate content: max. 100 mg/ltr.

Potable tap water usually fulfils these requirements. Local water utilities can provide information about the quality of the water they supply. If necessary, the water must be treated (e.g. softened) or distilled water must be used.

My city publishes water quality reports on the web. Not sure about the OP.

[ard]

Thanks for the info. Without proof from the dealer that the water they used met this spec, I would not accept tap water...

While a water quality report might make one feel fuzzy, it is far from an assurance that the water that was used on that day, at that tap, using that plumbing, met any particular standard.

Best practices dictate you use distilled water.

[rufusdedog]

JCL, thanks for the reference. I checked with the service manager at my dealer and he said they have always used tap (city) water with no issues.