oil level, but not the usual question
 

I park my 2004 S in the same spot in my shop when I get back from a ride.

If I go out for a day ride that would be about 150+ miles, sometimes when I get back the oil level the next day is right at the bottom of the glass.

Not worth adding oil but if I go for a ride the next day and park it in the same spot the next morning it could easily be at the top of the glass (or not until another time)

I am thinking the oil is not returning from the cooler maybe? is this possible?

What is in the engine is all oil, no fuel to be found, I'm head scratching here!

I've gotten myself suckered in to adding oil that was totally unnecessary for the same reason you mentioned. Beats me.

I was wondering if this has an oil thermostat and if that could be part of it.

In my experience the only way to get an accurate and consistent measurement is to put it on the side stand for a few minutes with a hot engine, then put it on the center stand.

My experience is the same as Jim's

The oil is supposed to venture back down into its bin with bike on side stand. Yet we see this magic trick on occasion. No clue.

I,ve got that part hard wired into my 9 BMW's brain. But this thing with a 1/4 cup difference is a little strange.

No center stand for me,arrive home off the bike,stoop down left hand on the handle bar right hand on the subframe and balance the bike,you have literally minutes to check after that the level will start rising depending on how much drains out of the oil cooler.

Hear ya. But sometimes I have to remind myself that I might just be looking for a problem that isnt even there

The only potential problem, that a few members experienced over the years, is neglecting to check the oil and their engines seized up. You should be fine if within a range, but somehow something happened with those guys...

I don't have the manual handy, but does it not say to check the engine oil level once bike is up to temp and after sitting about 10 minutes?http://forums.pelicanparts.com/support/smileys/wat6.gif

I think it's like this.
Side stand it for 5 mins after a ride then onto center stand and read.

I was tortured by this for a while with very inconsistent readings. Then I followed a consistent routine of letting the bike stand on the side stand while cooling for 15 minutes and then on center stand. Consistent readings verified by draining and measuring oil.

I'll change my routine starting this week end and see what happens, I could see how the oil cooler could airlock and not drain if it were level right after shutdown.

I've been tricked into adding oil several times just to show fuller than I want at the next check. Now I wait until I have seen a low reading twice and add less than I would have previously. Seems to be working "better". Even with letting the hot bike sit on the sidestand for 15 or so minutes before putting it on the centerstand it will give inconsistent readings. With this last oil change it seems to be making that last statement a lie. We'll see.

Frank

It looks great this morning after sitting on the side stand for 30 min last night then going to the center stand.

The "missing amount" if you will, is what it takes to just show above the lower level mark on the glass to halfway between the center point and the top of the glass. I will bet that is close to the amount in the cooler and lines.

If you take a look with it on the sidestand I think you'll probably come to realize that if your entire sight glass is covered you're good-to-go. No need to check it on the centerstand.

Had mine 20 years this year,but the first 6/9 months trying to work out how to check the oil level certainly had some ups and downs.... because even the hand book is vague.

The reality..their is an oil quantity,what the book doesn’t say,the level in the sight glass allows for a certain amount to stay in the oil cooler,some coolers leak more than others,hence why I found with mine I only had a couple minutes to actually check the ‘True’ level,because if I left it too long it would be up to the top of the sight glass or higher depending on leakage.

If you are are in any doubts,do a new oil change so you know the quantity is correct,run up till hot and then keep checking the oil level in the glass to get familiar with how much leakage you are getting from the cooler and how much time you have to check for the ‘Real’ level.

Thanks for all the replies! I've been a BMW rider most of my riding life so I have a long list of models under my belt including 4 1100S bikes and this is the first one that has had this changing oil level behavior to this extent.

BMW's...you just never know, which is why owning one is so interesting.