New Jersey BMW CCA

M54 Oil Consumption; 2004 X3 2.5L

I bought this vehicle for my 17 year old daughter in August 2016, mileage was 95872. Since the weather has gotten colder, oil consumption has increased and is now approximately one quart per tank of fuel. No evidence of oil drips under the car after being parked. On a lift, there is reasonable oil seepage for an engine at this age and mileage of 100,805.
One common issue with this engine is a problematic CCV valve. I measured vacuum with a water manometer at the oil filler cap. With engine cold, vacuum is 13" of water. After warming to operating temperature, vacuum went down to 9" water. There is also some evidence of "mayonnaise" under the filler cap and I noticed what appears to be blue exhaust smoke this morning upon startup. Air temperature was 26 degrees F (overnight low was 19 F).
I suspect the root cause is most likely an oil ring problem. Is the observed vacuum of 9-13 in. water within range?
Any other thoughts?

Thanks in advance.
Greg

If the CCV and it's associated pipes haven't been done yet ,do it ! if it freezes completely from the moisture in the cyclone separator , it can act as a siphon and pull oil from the crankcase and cause a hydro-lock and can cause serious damage in some cases. readings can be intermittent , but the moment it gets stuck , it can be too late. if the yellowish sludge is heavy under the cap ,might be a good idea to clean inside the valve cover.This is the number one reason for oil consumption in the M54 .

Ray,

Thanks for the input. Do you know if there is an official BMW test procedure to measure the vacuum at the oil filler in order to assess the condition of the CCV Valve?

Greg

Measure at the filler cap and specs for your car is 16mBar(Actual BMW spec for M54 engines), there is a 10% allowance either +/- but should be close. converted to inches of vacuum puts spec closer to 6.
Out of curiosity , have you tried to lift cap off while it's idling,when these things go bad (or starting to) it'll be difficult to pull it off (from excessive vacuum).

Yes, I removed the oil filler cap and could comfortably put my hand over the opening in the valve cover with the engine at idle. I was wearing a nitrile examination glove which created a good seal. With my water manometer, vacuum is in the range of 9 -13 inch of water (22.39 - 32.3 mbar). If my procedure is correct, the vacuum is above the specified pressure.

I found two documents online: BMW Service Information 11 08 03 and Jasper Technical Bulletin 05/07 (Jasper references M42, M44, M52, S52, M60, M62 and M73. Not the M54, but states: "A properly functioning pressure control valve is designed to maintain a slight vacuum (approx. 10-15 mbar) in the crankcase, which assures reliable crankcase venting during all engine operating conditions."

Could you share the BMW procedure, specification or document number you're referring to? I want to have as much specific information when I discuss with the technicians.

Thanks for your help.

Greg
Mobile: (732) 589-8427

Greg, with the mileage indicated and the conditions you are describing, I would go with Ray's recommendation and replace all the hoses and separator. You really do not want this to fail on the road. It's not good when it *really* goes bad.

Tim