I hope there is someone here with 407 engine experience that could possibly shed some light ?

I have finally upgraded my old 1997 406 after many years of reliable service and many things i fixed up through the years, to a 2006 407 coupe

Now i know everything was not perfect before the purchase of the 2006 407, but i cannot seem to pinpoint the oil leak, after cleaning the engine, it's little but it's there, leaves a little stain on the ground when parked, i have taken it to 2 workshops.

Both of them say the leak is coming from the sump gasket, however, then i took the car one last time to someone who has more time to do a diagnosis.

He said that the oil seems to be on top of the sump, and there is a thick pipe that is very lightly moist, a water pipe ? that is above the sump.

I told him could it not perhaps be that the oil gets blown upward on top of the sump from the sump gasket as the car moves forward and the wind pushes it up ?

He said he does not thinks so, he wants me to bring the car to him tomorrow so he can remove the exhaust and various other things so we can try and see if there is anything to see ?

Does anyone know what it could be ? Anything or any advice that can assist us tomorrow will be of great help ?