No oil leaks but huge oil loss or consumption.
 

Hi all,
After recently replacing the Valce cover gasket, OFHG and OFCG and front crankshaft seal i am still loosing about a quart of oil for around 1000 miles or less. I looked under the car to see if the oil pan is leaking and there is a little leak but never seen a drop on the ground even after running for 2 hours and parking overnight. The membrane on the valve cover is replaced and a small amount of vacuum is present at the oil filler cap. i do not have any other problems. no white smoke and no smoke from the engine bay nor even the slightest smell of burning oil.
I am due for an oil change and i do it every 5k - 7k miles depending on when i get time, I get it done at the dealer since its cheaper in texas. i pay about 55$ total. oil with filter change, All this leaks started after the dealer changed the oil from castrol 5w30 to mobil1 0w40. I keep topping it off with mobil 10w40 but would like to get y'alls opinion on the oil consumption. The crank case valve is replaced by the dealer under a recall. I do not know what to do at this point. please help

It might help to get a vacuum test done.

BMWs tend to be very picky with oil brands. I've had good luck using Castrol full synthetic 5w30.

I used to use Mobile One 5w30 from Costco. Would be down a liter every time I changed oil at 7.5k miles. Switched to Castrol 0w40 European from Walmart. No longer lose oil.

I buy mine from Walmart as well. I get 1 five quart and 2 one quarts 5w30 Castrol Syntec Full Synthetic.

i have an appointment at a dealer tomorrow. I even have the vanos solenoid codes. he is going to do the diagnostics for free. if the extended warranty applies il get new valve cover, oil pan gasket, solenoids, and ccv hoses for free. maybe this is a cause of excessive oil consumption ?
I just drove from NJ to Texas and I needed 2 quarts for 1500 miles. I have another quart added so that i can drive without headaches. i still get > 500 miles to a tank of premium fuel. slight power loss because of vanos codes and lot of hesitation on startup. after a few seconds it calms down and settles at 600 rpm no AC and approx 700 rpm with AC smooth idle. never stutters while driving. smooth while driving no blue smoke from tail pipes and no vacuum leaks as well. i checked by spraying brake cleaner around the valve cover and under and around the intake manifold. no jumps in rpm and idles smooth. may be the old valve cover ccv is clogged or the valve under the intake is leaking i have no idea. somehow i loose so much oil without a trace and even on low oil there is no dreaded lifter tick. its like its haunted. :wacko: I use mobil1 0w40. I am going to ask the dealer to see if they can use 5w30 and see if that makes any difference. I cannot keep spending so much on oil. a quart per oil change of 5k miles is acceptable. but this is beyond anything. My m54 330ci with 2 stage intake and 200k miles never consumed more than a quart for 6k miles b/w oil changes.
Any other places to look for oil leaks apart from the obvious main seals, VCG, OFHG and OCHG and OIL PAN ?

My guess is the CCV system is malfunctioning.

On my car its embedded the plastic valve cover.

On your car it might be under the intake manifold?

Mine is built into the valve cover as well. Is there any way to clean it ? I just replaced the membrane on the valve cover so i am a little hesitant to waste that..may be i can use some sort of degreaser and clean the CCV system.. ???

@Tejas I'm sure the dealer can figure it out and then you can decide whether to let them fix it or DIY.

If your CCV diaphragm is built into the valve cover, the proper way to replace the CCV is to get a whole new valve cover.

There are people on YouTube that have used a dremel and sawed the top off the CCV and replaced the orange diaphragm inside that gets torn.

Its an ugly process fraught errors.

Many people that have oil leaks in the valve cover discover its not the valve cover gasket failing, but the CCV failing and pushing oil out the valve cover gasket near the firewall.

The membrane I changed is faultless. The original one was taken out without damaging the actual valve cover and I epoxied the new one into place. Since I can open the oil filler cap while engine is running and I can feel a slight pressure I know it's good. What I know for sure is wrong is the actual CCV system itself. I am at the dealership now. They are looking at camps codes I had. Hopefully they will change the valve cover as well. I will keep you guys updated. I know for a fact that it's not supposed to consume that much oil because it started after the VCG change and the membrane replacement.