Inconsistent oil level N62 4.4 engine

[Doru]

Since I purchased this SAV, I experienced an inconsistent oil level. here is the scoop:
I do an oil change, check the level, everything is OK. A few days later, check the oil level, the level is at the minimum. I add 1/2 qt - the level is now in the middle. A few days later, check the oil level - the level is above the max mark on the dipstick. I leave as is. Then, over a few days, I check the oil level, now it's consistent above the max mark. Then after a few other days, more oil level checks, the level is at min. I don't do nothing, the level is consistent low for a few days. Days later, the oil level is again a smidge above the max level on the dipstick. I am not sure what is causing this. Talked to my friend Fmugur, and also checked the net for answers, and what I can think of are one of 2 issues (maybe both wrong?):

1. Maybe some sludge somewhere, which would not allow the oil to flow freely, and gets pooled somewhere above the oil sump?
2. Faulty Oil Check Valve (p/n 11367539857) part #8 in the below diagram

In realoem there are reported 6 of those, but I am not sure where they are located. The vid below shows the part, and he mentions they are 3 / cylinder head? Any heads up would be really appreciated (DIY? how hard? accessible? need to lift the engine?:

N62 BMW V8 Oil pressure light coming on 745Li 750Li 545i 550i - YouTube

[motordavid]

Just a thought: do you always check oil level after engine is fully warm, and then allowed to drain down for ~20 mins? And, on level ground?
GL, mD

[A B Able Truck]

I don't have a flat driveway - so there is always a variation on the dipstick depending where & how I park. (Can't pull in the my garage, it's full of good stuff my wife thinks I should throw away)

[bcredliner]

Need to find a way to check per motordavid suggestion on level ground to verify the oil level is fluctuating before troubleshooting elsewhere

[Omerta]

Check valves are generally in the oil flow path and prevent backflow. They should not interfere with draining.

[Doru]

My garage is level.
What stumps me is the fluctuating oil level. The car wasn't moved for the last week. So about 5-6 days ago I checked the oil level, and it was low. Checked it the next day - it was low like the previous day. Yesterday I topped up the e39. This morning I checked the oil level of the e39, and told myself: what the heck: let's check the X5 oil level again, and top it up. It was above the max level!!!.
And yes, when I check the oil level, the car is sitting for a while, so the oil has time to flow back in the sump. Why is that oil level changing so drastically after a few days - and this time the car wasn't even moved between these 3 oil level checks. Twice it showed low oil level, and this morning a smidge above the max level!!!!! It's insane!!!! This same behavior of fluctuating oil level is since I purchased this car (used). I don't know what to think, and I am not sure how much oil there actually is in the sump..... I wish I had that electronic oil level "dipstick" like the e9x.... This problem does NOT occur in the e39 or in the e46, or any other car I owned over the years.

[garrett.fell]

I have the same issue with mine. My dipstick is schitzo. It even varies from one SIDE of the dipstick to the other! Impossible to tell if it's nearly full or needs oil

I just make sure there's a good amount of oil on the stick....


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[Jungerishere]

All BMWs do this. LOL... I always check when the engine is at operating temperature and then turned off for 1 minute. Still varies little but not by much.

[electricalserv x5]

make sure the dip stick holder is push into place ,mine pulls out and cause erratic level,push it into place.

[E53inLA]

I've observed similar. I recall reading somewhere (not sure if it was here or another BMW site) to open the fill cap and let air in. The poster said the oil system is sealed up tight and pressure can build up. I have no idea if there is any real logic to this, but I figure it can't hurt anything to loosen the fill cap before checking the oil level.