Job 20-010 of the MB M104 Engine Service Manual states:

"Use water which is clean and not too hard. Drinking water fequently, but not always, satisifes requirements. The content of dissovled substances in the water may lead to corrosion. If in doubt, use distilled water."

Unless this has advice has been superceeded, it is MB's official word.

Also, "de-ionized" water is "hungry" for something, so I wouldn't use it, when distilled water is cheap and plentiful.


:-) neil
1988 360TE AMG
1993 500E

BTW- here's a link of the actual text, scroll down to bottom, and read the last sentence: