I have my BMW X5 50i consuming a lot of engine oil. Observed black and wet dripping oil with thick smoke through exhausted.
Most likely you have a bad cylinder head gasket (or cracked cylinder head).
Here are some tests you can do to check:
- When the engine is cold(!!!) open the coolant expansion tank and check the water surface with a flashlight. A failing cylinder head gasket might leak oil to the coolant.
- You may notice that the coolant level also decreasing (coolant leaks to the cylinder)
- When you do the first test with checking the coolant at a cold engine, close the expansion tank, and then use the car as usual. The next time when your engine is perfectly cold again, open up the expansion tank once more --> if you hear a hissing sound, as the over pressure leaves the system (and in extra: it has a smoky scent) then the exhaust gases also found a way to the coolant lines.
- In some cases power loss is also noticable
All of these symptoms point to a faulty cylinder head or cylinder head gasket. Some garage has testing equipment to find exhaust gases/oil in the coolant, so they can test your coolant as well.
If you allow the vehicle to idle for 15 minutes, and then step on the gas, does it smoke excessively?
If so, you're one of many (read almost all) that have bad valve stem seals. BMW revised the seals (the 'old' ones are affected by the engine's heat, and deteriorated prematurely), but they haven't settled the class action suit that's been filed against them yet.
All German Auto in Escondido CA has a solution that'll cost about $4,000. The typical BMW dealer will cost $10,000.
You got a turbo on that one, classic turbo seals leaking, do the rad thing don't burn yourself (do it when not too hot), also where you put the oil in lift the cap when ticking over check for to much back pressure,... and look for cream in rad and under oil cap. = head gasket.
if it is turbo seals make sure the oil return to the sump is clear of gunk this can back pressure the seals.
rebuild kits are cheap 100, another core is probably a better idea cheaper than a whole turbo.
Consuming a quarter(engine oil) in 5k is normal for big engine BMWs(mine do so) however if you have a blue gas coming out of your exhaust you probably have a burnt head gasket, to be sure you may open water reservoir cap(under the hood, do it when the car is stone cold), if compressed air came out with a pisssssssss sound while opening the cap and there is some green sludge under the cap, be sure you have a burnt gasket.
If you also have recieved this message too "The engine is too hot drive moderatly" with red color(the yellow one is a warning but the red one is a bad news) and you have the above problems for let say more than 3 weeks! you may harm your head cylandr as well. It is an appoximate estimation and depends on the weather condition, slope of the road you have droven on and .....
Suggestion: Go to a BMW mechanic or your dealer immediately and have it fixed before hurting other compartments of your engine.