There is an oily residue in the boost pipework yes, I was looking a few days ago when the compressed outlet from the turbo came off. Recently a test was done and the emissions were a joke really. Would it be cheaper to buy a new turbo (GT2554R) or would another GT25 turbo fit straight on without any new mapping needing done? Ie a focus RS turbo

Out of interest, how does it affect the turbo if it has 360 bearings and race spec balancing?