floridawriter

Has anyone experienced a very light, white colored coolant color, while knowing for sure that you had the correct Mercedes antifreeze in your engine? It's not engine oil or transmission oil in the coolant and there is no trace of coolant in the engine oil or transmission fluid.

mrbobby

Could it be cavitation in the water pump, perhaps a broken impellor?

floridawriter

Excellent suggestion, but that's not it. Water pump is perfect.

irokdastar

is it floating on top of the coolant or is mixed in . I think you have a blow head gasket where water and oil are mixing . Do you have a valeo radiator ? Are you over heating ?

Patton001

Any funny smells in your exhaust? You might want to look at your plugs to see if any of them look different than the others. My first thought is head gasket also if you don't feel there is a radiator problem.

floridawriter

No smell other than antifreeze. No, it's not the color of emulsified engine oil and coolant, or transmission fluid and coolant. The white color is thoroughly mixed with the coolant turning the coolant into a thin white milky mixture. Had me and my shop baffled too.

Turns on that the coolant overflow tank on the w209 and probably other Mercedes models contains a water filter inside the tank and filters the coolant through a filtering media of silica powder (white powder). The filter is supposed to be good for 150K to 200k, but my filter housing inside the tank cracked, allowing the silica media to mix with the coolant, turning it white. An odd thing to happen, and whoever heard of a water filter inside the radiator overflow tank, but there you go.