Is it okay to flush system with tap water?
 

http://www.ps2cho.net/downloads/phot...lant_drain.jpg

For the coolant of course...

It looks pretty horrible on my 260E....Obviously was not changed in a long time!

Would it be damaging to run on tap water for 20miles or so then drain it all out? I want to make sure I get all of this crap out of the system.

I used tap water to flush my system. I also did a back flush to try and get all the crud out. You should not cause any damage running straight water for a short time.

I've flushed several of ours with tap water, it should not be an issue if you drain it all out and use distilled/Coolant in the final fill.

Agree. Make sure to flush out the reservoir and heater core, and run the engine a bit while it's flushing to flush out the dead spots around the water pump. That should get all the old stuff out.

Okay perfect.

I got a nice 50:50 mix of G-05 and distilled water ready.

I was afraid that the antifreeze was oil when it first came out, but after closer inspection it was not...phew!

Thanks guys.

While I haven't read the G05 label. MB specifically says to use "pottable water" or tap water and NOT distilled water. The coolant is buffered .. not sure where you'll be with distilled water.


Michael

This is a quote from the September 2008 MB StarTuned magazine.
"Water Quality
In this article, we discussed proper cooling
system service procedures, anti-corrosion antifreeze
and tools to test and exchange the
coolant. One more subject we need to discuss is
something we very often take for granted. That is
water supply. "City" water for drinking is treated.
It contains fluoride or chloride salts due to the
treatment, so it is not desirable to mix it with
coolant. Do not use this, or hard water, in
Mercedes-Benz cooling systems. In the odd
chance you have a supply of spring water, either
bottled or from a well, do not use this, either.
Bottled water is not regulated and probably
contains minerals that can react with engine
components, and also acts as an abrasive when
passing through the cooling system. Instead,
use distilled water. It is the best to use since it
contains no additives. The slight additional cost
of distilled water should not significantly increase
the cost of the overall cooling system service
and eliminates harmful contaminants."

I used tap water (before I did any work on engines) in my wagon for the last few years and I noticed rust had accumulated when I rebuilt the head. I would not advice tap water for long term usage.

"I used tap water (before I did any work on engines) in my wagon for the last few years and I noticed rust had accumulated when I rebuilt the head. I would not advice tap water for long term usage."


How are you correlating rust to using pottable water? I think Mercedes and the engineers and chemists have more knowledge on the subject than us. I TRUST them and talking with long term Mercedes shop (Stu Ritter) whom has a BS in Chemistry- you want to use tap water. If you have extreme water in your area- just buy a gallon jug a the store. Stu worked on the everyday for 30 years never saw problems with regularly changed coolant.

M

Different areas have different city water (hard/soft), which should be taken into consideration in this discussion. Obviously the hard water is going to be the worst for both beast & machine. Here in Cincinnati, lurks the worst water around, so I have a filter for the entire house system, which takes out chlorine, lead, minerals, and all the rest of the crud. This filtered water has to be quite benign and completely harmless for engines. (Unfortunately the floride is filtered out as well, so we use a lot of toothpaste - for teeth, not coolant).

Ive never understood the philosophy behind "use only distilled water" when the cooling system is comprised of iron, aluminium, ruber, and other materials. Distilled water is still going to react to these different compounds eventually.

I "flush" my cars with tap water. In fact i run tap water in them and only change to a coolant in the winter months.

Neanderthal, you shouldn't run straight water during the summer, or anytime. Compared with 50% mix coolant, straight water has a lower boiling point. Once you have steam instead of water at the water jacket surfaces, heat transfer suffers. Search the archives using "nucleant boiling", where I've posted more on this subject.

The original question was whether it's okay to flush with tap water. It has no detrimental effect on the system if, at the end of the flush, you displace as much of the tap water as possible with distilled water. This allows you to use copious amounts of water for an effective flush without having to worry about the cost of distilled water.

straight water
 

.... is bad for any car regardless of temperature. Antifreeze - any antifreeze - has a lubricant for your water pump. Using straight water will lead to premature water pump failure. Don't know about your car but my 560SL hasan all aluminum block and head so I tend to use Zerex G05 or the MB stuff.

One of the important functions of "anti-freeze" is anti-corrosion. With straight water, there is no anti-corrosion protection at all.