I have a 91 Mercedes sel 300. When replacing the Mono valve,I noticed there was brown milkshakelike sludge. Drain radiator( found the brown sludge and green coolant separated not mixed together). Checked oil dip stick for coolant -Ok- oil is very black, checked trans dip stick for contamination Ok. Flushed all coolant systemwith garden hose,refilled with coolant. drove car around about 30mins and the car sat aweek. Noticed today the milkshake is back in the coolant reservoir. So reflushed coolant system again. Please help Thanks, Ian[/align]

 

I was reading somewhere on the forum that in some models that the oil and coolant intercoolers run together? Anyway a small leak could cause the oil to be pushed into the coolant.

NeV