I have oil in my water coolant. I have a Renault Kangoo with a 1.5 diesel engine. The Kangoo is running perfectly, but oil is coming out the top of the water coolant fill bottle under the hood. The consistency is thick and black, no foamy lightness which usually indicates water in the oil. I had the oil cooler removed, checked and re installed, it was in perfect condition. I am now looking at replacing the head gasket, though I do not feel confident that this is the problem! Garages are not happy about doing the job either. I have the car just one year and am reluctant to just discard it due to this problem, this is seemingly what garages would have me do.