Hello, I am looking for some advice for a long term issue that I have with my Galaxy 2.0TDi (2010/11).

Over the past couple of years I have noticed an increase in rough idling especially at startup, poor performance and increased blue smoke out of the exhaust again during startup. Whilst investigating what the issue is, I believed it to be turbo related so I replaced the turbo earlier this year. This has not addressed the oil issue and the symptoms seem to be getting worse again. My thoughts are if I can stop the oil leak from wherever it is and clean/replace mass air flow sensor. This will solve the other issues.

Is my theory correct and if so, what do I need to do. Sometimes if it's possibly a number of potential cause and it's cheap/easy enough to replace I would do that. I would like to try and solve this myself before I resort to going to a garage.

Your advice would be much appreciated.

IMHO, blue smoke should mean oil consumption and how much (accurately) would be my first question.

You have changed the turbo so should not be from those seals and any leakage needs to be checked for?

After that if the oil is being burned, then it either has to come from cylinder/ring issues or valve stem seals or leakage from an oil gallery into cylinders via head gasket or excessive crankcase flow from PCV - can't think of anything else??
From historic experience a compression test at each cylinder with throttle wide open (petrol, diesel should have no restriction but I don't know about the device in the inlet that appears to be similar)

Once those figures are taken, a tablespoon of engine oil into each cylinder and repeat compression test shows if it's cylinder or valves (increased values mean the oil has sealed the bores, otherwise, it's valves?)

There is a possibility with new diagnostic tools that you can get a very quick RELATIVE (not absolute PSI values) compression result using a current clamp and oscilloscope trace to see if one or more cylinders has a lower value - this would be a useful initial check (no dismantling but you have to find someone who knows what to do - Good Luck on that?)

As ever, these are my best guesses, given without warranty and always open to correction or improvement! (I decided to add this as my signature cos I don't know everything and never claim to be and expert!!!)