Posting this into the MK4 Mondeo forum as the mk4 mondeo 1.8L engine is similar to galaxy 1.8l duratorq engine.

 

I have a 2007 MK3 Ford Galaxy 1.8TDCI (Duratorq engine) that has recently developed a problem where there is a noise coming from the engine when accelerating in 4 ,5, 6 th gear .It sounds like a whooshing or exhaust noise but its only when accelerating.When in the lower gears and car standing still noise dosent happen.When its happening if you lay off the accelerator it stops.From checking the commom causes in the forums I had hoped I would find a cracked of split pipe to the turbo ,erg or intercooler circuit but I haven't found anything yet ,cant see anything wrong with exhaust either .I don't seem to be down on power any other ideas of what it could be.Could it be the turbo itself .

 

Hi there, it will be a turbo or intercooler hose split mate,it should only happen when your turbo kicks in the whoosh noise starts.

just visual looks at pipes won't always be the case I had to remove mine on my focus tdci it was the 90 degree turbo pipe coming from egr it had split from underneath.(easy sort) just finding it hint for you though look for sprays of oil in you engine bay this should indicate where the hole is n oil coming from.