White substance in radiator coolant

I had a leak in a radiator hose over night and ended up with a puddle in the driveway. After the liquid evaporated it left a heavy white stain. It also left white stains everywhere it had dripped on the hoses, etc. The coolant itself is the normal greenish color and nothing else has been added.

I've never seen this before and the local radiator shop didn't know either. Any ideas what the white material might be?

The coolant temp is fine unless I sit idling for 2-3 minutes in gear - then is would climb to full scale if I don't rev the engine.

Have changed thermostat, temp sensors and fan clutch within the last few months.

Thanks in advance.

driveway. After the liquid evaporated it left a heavy white stain. It also left white stains everywhere it had dripped on the hoses, etc. The coolant itself is the normal greenish color and nothing else has been added.

Any ideas what the white material might be?

would climb to full scale if I don't rev the engine.

This is an uneducated guess. White stains left by water can indicate a high mineral content in the water. Are you using well water to add to the coolant?

This is totally normal. Whenever I am in city stop-and-go traffic I notice everybody with a GM madly revving their engines over and over again.

GW

in the driveway. After the liquid evaporated it left a heavy white stain. It also left white stains everywhere it had dripped on the hoses, etc. The coolant itself is the normal greenish color and nothing else has been added.

either. Any ideas what the white material might be?

- then is would climb to full scale if I don't rev the engine.

Sorry, just now saw your posting. Just using city tap water but not high in minerals. I think it means trouble in my case. I let it run with the cap off until the coolant started circulating and it changed from normal greenish color to chocolate milk. I'll drain the radiator, fill and flush with water (only), drain and refill with new coolant and see what happens.

What vehicle? What engine?