Is this a common issue? Today when I drove home from work i noticed the yellow engine light, which according to the manual means increased emissions - so I just continued home because nothing else seemed to be wrong. But home when I looked at the engine department - surprise! No engine oil cap in place (I found it luckily near the engine - it didn't drop out of the car). But oil was everywhere (there was still enough oil left though)... stupid me that I didn't look at the engine department right after the warning light.

So I cleaned the cap, put it in place and started the engine but the warning light stayed on - should it go off by itself? Is it possible that it has opened by itself after longer period of not checking? It couldn't have just popped out because the small metal clips in the cap where straight and intact. And is it possible that some dirt has gone inside the engine (luckily it's wintertime)? Has this happened to somebody else? Lot's of questions... sorry.

First of all, check your oil level and don't drive the car without the minimum or you are in for some serious pain to the wallet. Second, whoever was the last person to put the cap on is either forgetful, or a retard, because there is no way to screw up putting on an oil cap. The light will either go away by itself or you'll have to get it reset.

My 06 525XI has the oil filter on top and its up-side-down. When removing, make sure the oil canister is empty before removing away or else oil all over engine.

My sump is 7 quarts.

1. I drain the oil

2. Loosen filter and let stand 2 minutes

3. Close drain/replace oil canister paper filter

4. Fill with 6 1/2 quarts

5. When all done, start car on level ground and view I-drive visual oil gauge asthis is the only way to verify level.

Forty five bucks and she's all good. Full Synthetic oil of course.

So you are suggesting I should change the oil or? Thanks, but I've changed the oil myself in every car of mine including this one - nothing new there :) Maybe I used a wrong word there... I didn't mean the oil filter cap, I meant the oil filling cap at the top of the engine. (I don't know the english technical words so well)

I think you should get the error codes read and reset them.
It is possible that the engine light goes away by itself after some driving though...

You're initial explanation was clear. I think Silver may be responding to a different post???

So do did you recently change the oil and possibly leave it off? Let us know the outcome of how much oil you may have lost. Hopefully not much and it was just a temporary oil pressure issue since the cap was off.

I have seen the oil filler cap blow off an older car due to a lot of back pressure and clogged PVC's, but that in itself is very unusual. I'm thinking it was left off.

OK, thanks. I changed the oil last autumn so it cannot be connected to that. The last time the hood has even been opened is about three weeks ago when I was at the BMW service, but even that was only so called quick service - angel eye bulb change - nothing else. So that's why I'm puzzled. It is possible that somebody looked there and left it loose but I doubt it. I was also thinking about the pressure... but could it really blow the cap off without breaking/turning the metal clips in the cap...hmm

The weather changed very rapidly today though, morning was -18 to -20c and midday only -5c if that has anything to do with it..... maybe not. I didn't loose so much oil after all, it was just scattered all around. The dipstick shows there is still 3/4 (when warm) between min. and max. Last time when I have looked at it (before this) it was still full max.