Will oil come to air seprator if there is any problem in turbo

no
oil in the hoses for the air indicates failing oil seals in the turbo or blocked oil return line from the turbo

check for blockages in the air filter system. replace the air filter. The only way that oil can get in to the turbo inlet hose is if the turbo is running in a vacuum and sucking oil fast the turbo seals Unless the turbo bearings are shot.

how often do you change your oil?,turbo engines tend to cook your engine oil,because of the turbine is also cooled by the same oil,check to make sure your oil is not black or (burned),should change every 2500 miles on a turbo,those little turbines get hotter than the engine,also make sure their is no air leakage in your air cooler,that can burn up your turbine!

Your turbo has provisions for oil to cool bearings and the seals have blown out, although from my experience the result is white smoke if it is pumped into the hot exhaust. The reason it goes is usually a combination of things-high boost at cold temperatures, thicker oil under start up conditions or running oil that is a higher viscosity than recommended. Your crankcase pressures, the condition of the PCV and subsequent systems also contribute to this problem

The return path from the turbo is sometimes the issue and has to be clear, and I think the turbo seals could be bad, but black smoke is usually associated with excessive fuel.. You will also get alot of smoke when the oil return is slow to return the oil to the sump and it backs up into the turbo. It forces it's way out of the seals making it smoke.

This is the turbo air cooler hose and most of them have some oil in them from the turbo. i would replace the hose and keep an eye on it, the problem may be a worn turbo. the turbo is sucking in oil, the turbo may need replacing but i would nt replace it right now, just replace the hose and keep an eye on the engine oil level, if the turbo is working and the engine is not using oil and you dont see smoke coming from the exhaust system when accelerating then just replace the hose for now, hope this helps.

Check the intake pipes from the air filter to the intake on turbo in case its got a air leak and its sucking in dust and grit ,If i knew what was being damaged in the turbo i would have a better idea ,if its the bearing then it has problem with the oil feed being partialy blocked with gunge from lack of oil changes which is the normal reason

Check the oil line going from the oil pan to your turbo. Somehow the oil that is mean to keep the turbo lubed and cooled is blowing through the impeller into your engine... not good.

Change your air filter ,the engine want to breath if air filter is plugged it will try to get air from your crankcase

I wouldn't drive it until you get a scan done to determine what the problem. Diesels are very expensive to fix. I would lean towards the cam shaft sensor has failed but don't quote me on that.

What you have described is a classic turbo air leak. Check the clamps & air lines from the turbo to the intake. If you do not find an air leak (you should be able to hear the air escaping) it will be a turbo problem. Unlike gasoline engines too much fuel in proportion to the air will cause the vehicle to run hot and also to smoke.