hello everyone, my 2001 x5 have 113,000 miles and one cold day it smoke alot from the tail pipe also oil coming off from the tail pipe
i change the oil seperator and all the hose and i notice that there is no oil in the engine and coolant went low
i change the and filter when started i still got lot of smoke and there is a knocking in the engine
do i need to replace the engine or can i rebuilt it, what will i need to rebuilt it and how much will it cause me or is there any thing shouild i check for

thank you