Hi,

I was told by local MB mechs in my country (the Philippines) that using 50/50 MB coolant/water mix corrodes the water (coolant) channels in the head - making them larger and thus requiring a trip to the welding shop where it will be "resized" back to normal. For this reason, the local mechs are saying that it's better to use water than coolant.

Is this true? Has anyone actually needed a water channel repair in the head/block due to corrosion? They're quite positive it is not the well-known headgasket problem.

I'm guessing that the local mechs use regular tap water (very hard water here) when creating the 50/50 mix. I for one am leaning towards using distilled water and Redline's Water Wetter (ph8.6) only.

Any thoughts on this possible "urban benz legend"?

Thanks