My diesel engine bmw x3 is smoke too much

Mr. Nkosi.
for the BMW X3 2000 over engines there is an issue with their engines. The threads on the cylinder block where the compression gasket and cylinder head torqued just pull off and lost the correct tightening torque and starts the problems with loosing water or burning oil etc. Ask you mechanic to do a search about it and also check your engine for this possibility.

Then the conclusion I would see is the engine is burning oil or the fuel injection is the source of the smoke (excessive fuel) or the new or rebuilt turbo is defective.

perhaps some water condensation in the empty tank that then caused the smoke and shaking during warming up.

Refill with good branded Diesel a full tank and have a drive for 30 mins possibly warming at high revs (or low gear to warm faster)
Enjoy

Diesel engines smoke when under a heavy load. Unlike a gas engines, a diesel engine uses fuel that is more like an oil.Smoking is a good indication the fuel is not completly burning because of loaded engine spee. White smoke indicates the fuel is not ignitingefficiently. Truck, boats, tanks abd anything else using diesel fuel will smoke when it gets more fuel than it can use.. Easing up on the throttle will lessen the smoke but not eliminate.. Of coarse if the demand is lessened by applying less loadyhe fuel consumption drops.Not to worry as long as the smoke doesn't attract the EPA.

egr blocked
chack air pipes
mass air flow sensor

There are 2 things you can check. First check your o-rings in your transmission. If that's good check your converter.

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Mr.Fatodu,
according to your statement, your car is using enough engine oil. Now this depends to how often you were changing the engine oil and the guality of oil used. For me all BMW'S OIL CHANGE Every 5000 miles long drive and 4000 miles short drive. Oil used full synthetic Castrol 5W40. Since now you have the smoking issue should use an oil treatment additive FORTE For stop smoke. Trythis first and see whether you have any success.

chances are you picked up some s..t from the bottom of the tank,use some injector cleaner when you next top up with diesel,should clear the smoking problem.

white smoke from a diesel is usually lack of fuel, black smoke is to much fuel, check your fuel filters for restriction. this is providing that the smoke is not coolant in the exhaust but if that's the case it should be overheating. also if it is cold were you are you might have a fuel gelling problem that will also cause white smoke. just put some anti-gel in the fuel and see if the problem goes away.

Engine also smokes when car driving if turbocharger still faulty. Did you change the engine timing belt (the timing belt kit) meantime? What about engine oil consumption? When engine glow plugs (one or more) burnt then engine exhausts white smoke at idling. Also white smoke at engine idling when water is still present in diesel fuel.