Oil in intercooler pipes 300tdi - bad yes??

[Ringky]

Since an overheating issue back in Feb (which after much investigation turned out to be a dud new thermostat purchased from LR dealer) the old girl has lacked a bit of punch. I was worried about the head for a while, however there has been no loss of coolant nor any visible oil contamination.
After reading defendozers ordeal earlier in the year with a loss of power, i decided to look at some of the suggestions in that thread. When i popped the intercooler hose off nearest the turbo there was a good black coating of oil ?(well its black and smells like oil) through the pipework - both hoses as it turned out. I also noticed oil around the turbo housing which is definitely not from any leak on the engine block.
Is any of this normal, or could it perhaps be part of the performance woes??
Thanks in Advance
Ringky

[Scouse]

Oil residue is normal. It's a good idea to clean the hoses & intercooler out every few years or so.