mk5 golf gt tdi oil in header tannk, any ideas?

[sam-372]

hi guys hope u can help, today i noticed cloudy colared water dripping from sumwhare at the back of the engine near the turbo, then i lookd in th header tank then they were oil mixing in with the water, so i flushed it out and filled it up with water again and ran the engine and the water seemed to go a cloudy colared again and when i checked it again in the afternoon the water level was very slowly going down and running out at the back of the engine again, then on the down pipe of the exhaust then there a slight bit of oil on there, did think it was maby the oil cooler gone? but then i spoke to a friend and he said the turbo might be water cooled and mixing in there? can any 1 shed any light on this? its mk5 golf gt tdi 140 88k miles, oil cooler? turbo intercooler? she isnt heating up when am driving her or smoking when reved hard,

any forgot to say, am only had the car for 3k miles and when i was coming up from biringham to aberdeen the i lost the turbo twice and emsions warning light came on the dash, and engine management light came on and swithed the car on and off then the turbo seemed t work again, but the emgine management light stayed on for a few days b4 he went off