Peugeot306 meridian1998petrol.Is it normal to top up tap water to the radiator pump 500ml every 3days?

Question

no leaking noted nor mixture fr the engine oil,it's just the water level dropping so i kept on refilling it with tap water.water temperature is just fine to normal level. travelled distance/day approx. 25 miles. distilled water for battery is safe for radiator use?

Answer 1

No. You probably have a leak which needs fixing. The coolant level should remain constant indefinitely, except for the thermal expansion.

And the system was designed to work year round with the water-antifreeze mix, not just water. The antifreeze contains rust inhibitors and helps raise the boiling point to about 120 deg. C, which may account for part of your loss (evaporation of water).