106 GTI Engine Overhaul

Hello guys, I'm new to the forum. In my 106 gti vehicle that I bought about 2 weeks ago, there is more than enough black oil coming from the throttle of the vehicle, which burns heavily oil. What does this indicate? I wanted to ask here because there is no Gti engine. Is there a good master in Istanbul, where I can open the Gti engine?

A few places that I know of, but they are dealing with old vehicles for some reason, if there was Ankara, my brother