Yesterday, I was just about to complete its annual service with an oil/filter change and noticed the noise insulation tray was covered in a film of oil/grit. It was not enough to be leaking onto the garage floor but the sump cover was fully covered in a film of oil.
At first I though the liquid seal of the sump cover had perished and was now weeping. However, having cleaned it off with wd40 and paper towels, I could see oil deposits further up on the passenger side of the engine. Driver side looked fine.
Definitely no oil around the oil filter area nor the oil filler (in case I had spilled some).
The highest point looked to be a connecting flange below the turbo (looking from the underside of the car). This flange is I think to do with exhaust gasses (not oil) from the turbo but it was covered in oil - dripping from above it (??) To further investigate I will first have to remove the turbo heat shield.
An oil check 4 weeks ago showed I had lost about quarter of a litre (I topped up thinking as it was near its service this would be the reason for the loss). Today it needs a further quarter of a litre.
So this is not a big leak but definitely a leak.
Before I go charging in, can anyone give me some pointers as to likely cause?
Thanks in advance.