Hi everyone, first time user, I need advise on a problem with my 407 1.6 hdi. When accelerating I have lost power on inclines so have to go down the gears. I was told I have a fault with the turbo. Looked at turbo and noticed soot. Now there is oil on the outside of turbo housing and the dipstick is black all the way up to the holder. Could it be a hole in a pipe or is it more serious. Your help would be greatly appreciated.

a lot of turbos get oily to no detriment. a turbo charged engine needs plenty of oil changes with quality oil and always a clean air filter.
turbo boost pipes do sometimes leak and if perished intake hoses can collapse during high air demand and strangle the intake. i suggest a close inspection of all the pipes and hoses including the little ones to the wastegate and control unit. if there is nothing obvious then a visual check of the compressor is needed and a twiddle to make sure it is not seized, bent or rough and that all the vanes are present. start it up and make sure the turbine is ok. if all ok then it is probable that boost pressure is possible and the fault lies with the electronic control.
intercoolers can sometimes get blocked with sludge or carbon. EGR systems on diesels also need a periodic de grotting.