[BuddyT]

So yesterday I changed my oil and I only got about 6 quarts out. Prior to draining the oil level was 3/4 full on the e dipstick. Does the engine hold another 1/2 quart that won’t drain out?

When adding oil back, I put the recommend 6.9 quarts in. Ran it for 20 minutes and the gauge displayed full.

Is it possible I overfilled, but the e dipstick doesn’t show that?

Some thoughts and answers to this would be greatly appreciated!

[PhaceN52]

When you drain it a little oil remains in the pan, like about 0.25 liters, I'd be concerned if you put a full quart/liter extra, but if the e-dipstick doesn't say that's overfilled don't worry

[mainbearing]

Sounds about right. I usually just put 6.5 qts in.

[crashoverride]

Lots of nooks and crannies and oil is like molasses there is a certain amount of slop in over and underfilling. Drive it like you stole it and don't worry.

[StradaRedlands]

Yeah, .5 qt easily in the filter, galleys, still in the pan. You're fine. Fill up with 6.5 and drive it. Check the level when it's warmed up in a few miles. Should be close to full, and no need to add if it's not down to the low line.

[BuddyT]

Originally Posted by StradaRedlands

Yeah, .5 qt easily in the filter, galleys, still in the pan. You're fine. Fill up with 6.5 and drive it. Check the level when it's warmed up in a few miles. Should be close to full, and no need to add if it's not down to the low line.

Thanks so much I though the same thing just wanted to 2x check. You da man!

[Efthreeoh]

OP, I own two BMWs with N52 engines and have done 48 oil changes on the N52. Just to set my level of experience with the N52, my combined mileage on both engines is 540,000 miles.

Unlike most people, I change the oil with the car level. Most people just jack up the front of the car, crawl under and perform the oil change. They should take the time to set the car level on four (4) jackstands because (a) it is safer to work under the car when all 4 tires are off the ground, and (b) it puts the car level when servicing it, which is how it was designed to be serviced.

That said, the N52 comes with either a steel oil pan for the manual transmission variant or an aluminum oil pan used for the automatic trans variant. The steel pan drains out of the bottom of the pan and the aluminum pan drains from the side. I have no experience with the aluminum pan oil service. You didn't say what transmission your car has or what method you use to change the oil (level, or slanted - lifted at the front only).

When drained with the car level, all of the oil drains from the engine block. There are a few ounces left in the oil pump pickup tube. There are also about 3 ounces left in the oil filter housing, which is supposed to be siphoned out during the oil change. The correct method to change the N52 oil (BMW's instructions) is:

- Lift and properly support the car so it is level
- Remove the oil filter from the oil filter housing (this prevents any vacuum to form in the engine block while the oil drains out)
- Remove the oil drain bolt and drain the engine oil
- Siphon out the residual oil in the oil filter housing
- Install the oil drain bolt
- Assemble the new oil filter and reinstall it into the oil filter housing
- Refill the engine with oil. The official stated capacity is 6.5 liters or the equivalent 6.9 quarts

Because the oil level is determined by an electronic sensor, it is not a direct-read device and is it not accurate right after the engine is refilled with oil. To prevent over-filling the engine block with oil, you should only add oil in full 1-quart or full 1-liter increments. Further information on how the e-dipstick works is found here: https://www.e90post.com/forums/showthread.php?t=1533444

[bimmermech123]

Personally, whenever I do oil changes on my E90, the car is level on 4 jack stands and I only add 6 liters of oil when doing an oil change. The e-dipstick usually reads 3/4 full or sometimes completely full. No matter how you you position the car, level or the front end jacked up, 0.25-0.5 liters remains in the oil pan and the rest of the engine. Hence, it is always better and easier to underfill slightly than to overfill slightly. My advice, start with 6 liters, then add more if necessary.

[BuddyT]

Thank you so much!

[Efthreeoh]

Originally Posted by bimmermech123

Personally, whenever I do oil changes on my E90, the car is level on 4 jack stands and I only add 6 liters of oil when doing an oil change. The e-dipstick usually reads 3/4 full or sometimes completely full. No matter how you you position the car, level or the front end jacked up, 0.25-0.5 liters remains in the oil pan and the rest of the engine. Hence, it is always better and easier to underfill slightly than to overfill slightly. My advice, start with 6 liters, then add more if necessary.

I disagree.

If it was a mechanical dipstick, underfilling, then running the engine, letting it sit for 10 minutes to get all the oil to drain back to the sump to top off, then yes that is the proper technique. But the N52 is different. The e-dipstick is not reliably accurate until the engine is run and meets the various parameters to update the measured level. This takes at least 5 miles and 20 minutes constant driving to get an accurate measurement from the system. Most people used to mechanical dipstick engines will end up overfilling the N52. I wrote the thread on how the e-dipstick works because a gearhead friend of mine, who is highly experienced with automotive mechanics (he developed an engine tune for the 1980's Bosh Motronic system used in the Porsche 944) blew the front seal on his son's 128i the first time they changed the oil in it. He did not understand the e-dipstick was not reporting the real oil level. I figured if he screwed the pooch on the N52 refill most others could to.

Like I said, I've done 48 oil services on the N52 since 2006. I follow the same procedure for every oil change. Never has the engine reported it is overfilled. With the N52 because VANOS uses a lot of oil to control the camshafts it needs a large volume of oil. Because the E9X is sold internationally, it can be filled using quarts or liters, so the level of oil is not critical between the few ounces difference between a liter and a quart. When the +qt notification comes up you can add a full liter or a full quart, it doesn't matter. The oil pump is a variable-volume oil pump, in its resting state (engine off) it retains very little oil, the residual oil in the block (once the OFH is drained and siphoned out) is in the oil pick up tube. Also, I have a pneumatic oil extractor that (just for fun) I use to scavenge any residual oil in the pan, its maybe half an ounce.

If a DIY'er doesn't understand how the e-dipstick operates, filling the sump low and then trying to top it off to max-full can lead to more over-filling errors than just draining the engine in a level sitting car and refilling with 7 quarts (6.5L) of oil. Because the e-dipstick reports the oil level in 1/4-unit increments, it can show the level as 3/4 of max but be nearly 1/2 quart/liter low. Most DIY'ers used to mechanical dipsticks expect to add oil and see an immediate change to the oil level reading, but the e-dipstick is reporting its last known oil level before it updates again. That is what happened to my gearhead friend.

[BuddyT]

Originally Posted by Efthreeoh

OP, I own two BMWs with N52 engines and have done 48 oil changes on the N52. Just to set my level of experience with the N52, my combined mileage on both engines is 540,000 miles.

Unlike most people, I change the oil with the car level. Most people just jack up the front of the car, crawl under and perform the oil change. They should take the time to set the car level on four (4) jackstands because (a) it is safer to work under the car when all 4 tires are off the ground, and (b) it puts the car level when servicing it, which is how it was designed to be serviced.

That said, the N52 comes with either a steel oil pan for the manual transmission variant or an aluminum oil pan used for the automatic trans variant. The steel pan drains out of the bottom of the pan and the aluminum pan drains from the side. I have no experience with the aluminum pan oil service. You didn't say what transmission your car has or what method you use to change the oil (level, or slanted - lifted at the front only).

When drained with the car level, all of the oil drains from the engine block. There are a few ounces left in the oil pump pickup tube. There are also about 3 ounces left in the oil filter housing, which is supposed to be siphoned out during the oil change. The correct method to change the N52 oil (BMW's instructions) is:

- Lift and properly support the car so it is level
- Remove the oil filter from the oil filter housing (this prevents any vacuum to form in the engine block while the oil drains out)
- Remove the oil drain bolt and drain the engine oil
[...]

If it helps I changed the oil with the engine having sat for 10-15 minutes and jacked the left side of the car up, since the drain bolt is on the right side. I did this in an attempt to get everything out

[BuddyT]

Originally Posted by BuddyT

If it helps I changed the oil with the engine having sat for 10-15 minutes and jacked the left side of the car up, since the drain bolt is on the right side. I did this in an attempt to get everything out

Either way do you think I’m 1/2 quart over filled? I did not siphon out the oil filter housing.

[mainbearing]

If the oil sensor does not tell you it is overfilled, then I would not worry.

If OCD, then just drain 1/2 qt if that makes you feel better. I would not worry about it, and at the next oil change, just put in 6.5 qts.

[BuddyT]

Originally Posted by mainbearing

If the oil sensor does not tell you it is overfilled, then I would not worry.

If OCD, then just drain 1/2 qt if that makes you feel better. I would not worry about it, and at the next oil change, just put in 6.5 qts.

Much appreciated! Might just take some out of the oil filter housing and place it in a single quart bottle to measure what I take out

[BuddyT]

Update: took a 1/2 quart out and dipstick now reads 3/4

So those who said start with 6 liters are in fact correct!

[mrjimyjohn]

Does anyone know the real level at which the car reports overfilled? I have never seen this warning.

Would be great to know what a maximum safe level to add after the +1L warning is. Ive poured in at least 1.25L before just to empty a jug… no warning.

[Efthreeoh]

Originally Posted by mrjimyjohn

Does anyone know the real level at which the car reports overfilled? I have never seen this warning.

Would be great to know what a maximum safe level to add after the +1L warning is. I've poured in at least 1.25L before just to empty a jug… no warning.

I don't know why everyone is making this so hard.

The BMW spec for oil capacity with filter change for the N52 is 6.5 Liters (219.8 ounces) or 6.9 quarts (220.8 ounces). When the +1qt (+1L) appears, add in just 1 quart or just 1 liter, it does not matter. When changing the oil reload the sump with 7 quarts or 6.5 liters, it doesn't matter. The system measures the oil level accurately rather than precisely.

The problem lies with the old-style mechanical dipstick. People are used to physically seeing a line of oil on a dipstick and it is real to them. Using an e-dipstick is not reality to them because they don't trust a sensor for something they are used to actually seeing and reports with precision. There is a value of maximum oil capacity (level) that is an imprecise range but as long as the engine has between 6 to 7 quarts in the sump it is within the safe operating range. Most people have never read the owners manual for a mechanical dipstick engine and are OCD, so they think the engine needs to be at its maximum oil level all the time. But every mechanical dipstick engine instruction for taking a reading of the oil level tells the owner if the oil level is within the range of the min. and max. markings on the dipstick the engine oil level is within the safe operating range. It instructs the owner to only add oil when the oil level is at the minimum reading.

Because the BMW e-dipstick does not precisely report oil level (it reports in 1/4-units of measure - approx. 8 ounces) and because it takes 20 minutes of constant driving for the system to update, trying to use the e-dipstick to precisely top off the oil level to max like one can with a mechanical dipstick, is the wrong way to use the system. The correct way is to add oil to the engine once the +1qt (+1L) notification appears and only add 1 quart (or 1 liter). It is no harder than that and there is no need to second guess the system.

[Efthreeoh]

Originally Posted by BuddyT

Update: took a 1/2 quart out and dipstick now reads 3/4

So those who said start with 6 liters are in fact correct!

Well, if you drained out 1/2 quart, the e-dipstick should report half of the bar on the gauge cluster rather than three-quarters of the bar...

Now do you understand the difference between the system reporting accurately vs. precisely?

[BuddyT]

Originally Posted by Efthreeoh

I own a BMW Z3 with the M44 1.9L 4-cylinder engine, which has a mechanical dipstick (and no oil level sensor whatsoever). I changed the oil in it yesterday. The M44 has a similar oil aluminum pan set up to the aluminum-pan N52 with a side drain. I have a 2-post lift, so the car is always level when I work on it. I drained the oil using the procedure I posted earlier, which is to open and remove the oil filter housing cap w/filter, then remove the drain bolt. While the oil was draining, I checked tire pressures and refitted the cap with the new oil filter.

Once I turned my attention back to the draining process, as usual, the oil was just slowly dripping from the oil pan. With this thread in mind and just to amuse myself, I pulled out my pneumatic oil extractor and tried to suck out any residual oil sitting in the oil pan, barely any came out; the extractor uses a clear plastic tube so you can see what it is pulling out. The M44 oil filter housing does not retain any oil like the N52 does.

I reassembled the oil filter, reinstalled the oil plug bolt, and refilled the engine with 4.5L of BMW oil. The level was right on the max line of the dipstick.

The engine in the E9X is canted over to the right by about 15 degrees. Lifting the left side of the car cants the engine over farther to the right, but I doubt that has any adverse effect of retaining any material amount of oil in the engine block or cylinderhead.

You are way over thinking this. If the e-dipstick is not reporting an overfill condition or an oil level minimum condition (i.e. +1qt [...]

Much appreciated for all of this, and yes I am a big overthinker so this puts my mind at ease. Overall my car was overfilled by only 1/4 quart

[gbalthrop]

Originally Posted by Efthreeoh

I don't know why everyone is making this so hard. [Willful Ignorance ]
The BMW spec for oil capacity with filter change for the N52 is 6.5 Liters (219.8 ounces) or 6.9 quarts (220.8 ounces). When the +1qt (+1L) appears, add in just 1 quart or just 1 liter, it does not matter. When changing the oil reload the sump with 7 quarts or 6.5 liters, it doesn't matter. The system measures the oil level accurately rather than precisely.

If you do NOT believe "F30" you do so AT YOUR PERIL. (Willful Ignorance ;-)
Don't argue with 48 DIY Oil Changes. One of 'BIGLIEST' problems these days is that many folks can't tell fact from fiction, or experience from BS.

Only thing I would add:
Those in "Operate Wrench BEFORE engaging MIND" mode will fail to WARM engine for 5 minutes BEFORE draining oil. If you do NOT get ALL the old oil OUT, then of course you don't need to add as much fresh oil. Even with a HOT engine that was driven BEFORE draining, and AFTER removing Filter element and ALL oil in OFH, oil still drips from Pan Drain Plug 5 minutes after plug removal. If oil is NOT hot (is MORE Viscous/ thicker) it is less likely to drain completely, particularly in cold weather.
George

[bibina33]

Uno Online said:

So yesterday I changed my oil and I only got about 6 quarts out. Prior to draining the oil level was 3/4 full on the e dipstick. Does the engine hold another 1/2 quart that won’t drain out?

When adding oil back, I put the recommend 6.9 quarts in. Ran it for 20 minutes and the gauge displayed full.

Is it possible I overfilled, but the e dipstick doesn’t show that?

Some thoughts and answers to this would be greatly appreciated!

It's possible that your engine holds a small amount of oil that doesn't drain out completely. This can happen due to oil being trapped in various parts of the engine, such as the oil filter, oil cooler, or oil passages.