High oil Consumption, BMW M5

A 728i? Where do you live? That car has never been available in the US.
In any event, a 2.8 liter BMW engine has a cam chain. If the oil is changed regularly, that chain and the guides should last at least a quarter million miles. The VANOS may not last that long, but cam chains are not a high failure item.

It could well be a PVC valve. The PVC plumbing on e46s is not one of BMW's best designs, and it needs to be cleaned out every 100k miles if not sooner.
Not likely a rear main. I have never seen a failed rear main seal on a 6 Cyl BMW.

Are you sure it is not power steering fluid? I would be surprised if a 2003 were not leaking a little power steering fluid by now if the hoses have not already been replaced.
Another common oil leak is the hose that feeds oil to the VANOS.
If the leak is toward the rear of the engine, I would look for a valve cover gasket leak.
The service engine soon light is almost certainly unrelated to the oil leak.

Well, the key question is how much oil are you consuming...Quart in 600 miles or more is considered normal, but I prefer 1 quart in 2500 miles...

If high oil consumption, consider hotter plugs, and decide if engine work makes sense. If only a cylinder or two, try hotter plugs in those cylinders

If no oil consumption, look to weak spark, damaged wires, etc.

oil sep not causing this issue,this would be caused by the crankcase valve both on 6 and 8 cyl,if you have a 6 the part is locaed below the intake behind the throttle,you must also remove the dip stick and clean out the drain on the stick,if you have a 8 cyl than you must rere the intake and repl the rear cover and oil drain, also this issue is more commonly found when temps are very cold.either way this should be replace to prevent furhter damages to the enigine.this should solve the oil consumption issue as long as there are no other leaks present

There is a lot wrong with "low oil" and low oil is not normal in a low mileage healthy engine.

The dealer is fobbing you off in the hope you will go away.

If the oil is being changed at least every 5000 miles or so there should be minimum oil depletion between changes with only very minor top up needed. Some oil consumption is normal but it should be minimal.

If the oil level is dropping to a very low level in about 4000 - 5000 miles of normal motoring you have a significant problem. The oil is either leaking out or the engine is burning excessive oil or a combination. If there is no leak through faulty seals or by other means such as oil escaping into the cooling passages of the engine, then there is excessive burning.

These engines are known for excessive oil consumption because the problem is a common one in the 06, 05, 04 and previous year builds back to about 98/99. The dealers know all about this problem - as does BMW - and they will try to fob you off until the car is out of warranty because the fix is expensive.

From what you say the problem has not been fixed on your car. Document the oil loss and insist on your warranty rights because your engine is using excessive oil and this is NOT normal in a properly functioning motor with as few miles as yours has. Make it clear to the dealer that you are well aware that excessive oil consumption is a common problem in many of the 325 petrol engines and you want it fixed under warranty.

Then sell the car as these vehicles will cost you quite a bit in repairs once out of warranty and once you clock up around 60000 miles or more. If you have an auto you can expect major problems at about 65000 miles (later if you are lucky) and replacement of the transmission will be necessary. Once you notice any significant problem with the auto transmission it is on it's way out.

Cheers
Sean

hi, this consumption seems high, i would take it to a dealer and ask them to check the oil sensor.......
P.S. is there a lot of smoke coming from the exhaust, if so, it may be burning a little oil, ask dealer to check it

GM HAS A BULLETIN OUT PIP4574E

THE BULLETIN PERTAINS TO AN OIL CONSUMPTION PROBLEM WITH THE ENGINE. IT INVOLVES THE LEFT HAND VALVE COVER AND THE LIFTERS. THE LIFTERS ARE THE MAIN CONCERN, THEY PUMP TOO MUCH OIL AND IT GETS PUMPED INTO THE VENT HOLES IN THE PCV AREA OF THE VALVE COVER ALLOWING IT TO BE SUCKED UP INTO THE INTAKE MANIFOLD AND BURNED.

BOSTRUCK IS CORRECT ABOUT YOUR WARRANTY.

U can have a cylinder leak-down test run for around $100 to see if rings are ok but I am sure it will just indicate you need to overhauled the engine, that much oil consumption is only caused by worn rings/cylinder walls or a blocked or partially blocked crankcase ventilation system (PCV).

oil consumption is normal on BMW's especially if you drive the car hard and especially if it is still cold.

Hi

The lifters can be cleaned by getting the engine nice and hot and then adding an engine flush to the oil and leaving the engine running at a high tickover for about 15 to 20 minutes, and then giving the car an oil and filter change.

Are you sure its the tappets and not the timing chain?

Regards

Geordie