Hello fellow w221owners my 2007 s550 rwd has a terrible brown color to the coolant. Probably oil. I was told the engine cooler may be the culprit and start there before assuming it's the head gasket. Any experience with this one mates? I'm also told it could be the radiator? Any help or previous experience with this would be much appreciated.

 

Went for a oil change at mercedes nothing. I heard literally nothing back about. Am I crazy?

 

Not crazy but it seems like you like giving away money. The course of action would be to replace the oil cooler gaskets (cheapest option) or buy a new oil cooler, the process is the same whichever route you take with respect to what you need to take apart to replace it or the gaskets. The job requires you to drop the coolant and the oil. The coolant reservoir and the thermostat should also be changed as well as the belt, tensioner and idler pulley since you have to pull the belt off too to do the job..