Moin moin! Since my Volvo pushes oil on the valve cover and the cooling water is rust-brown, the next few days I have to: -release oil -replace oil trap(clogged, new is da) -unscrew hoses of the same free -unscrew oil pan, clean and screw it again with a new liquid seal -release coolant -clean the whole cooling system with correga tabs and plenty of water -refill new coolant So and now my questions come to the action 1.In order to solve the oil drain screw I have heard a quadrant nut, since the screw is an inner quadrant? Some of these things I believe to be right for myself! 2. In order to replace the oil filter I need a key from Volvo(~15€), or is this also possible differently? 3. Must be used as a coolant the green from Volvo or does the green from the accessory shop, or the supposedly high-quality red from Audi (work there)?