Used Engine on 1999 Volkswagen Passat

How will you know the miles?

Asked by for the 1999 Volkswagen Passat
A used engine is always a risk. You have no way of knowing the mileage. I would always remove the valve cover look the oil was changed frequently (if so the engine should be clean inside not dirty black), I would remove the oil pan and check the bearings, and if all is OK I would replace the timing belt, seals and water pump.