[Credelius]

Hi All,

I'm trying to identify a source of oil leak in my 2005 X3, 106K miles. I've already found one - it's definitely coming from the oil level sensor, but it's not likely related to what you see on the picture with a bolt. Could it be related to that wet bolt or is it something else? Please share your thoughts.

Three pictures are attached:

1. Leak around the bolt where the red circle shows the highest point of the leak.
2. Leaking oil sensor. It leaks where plastic meets the rubber.
3. Oil sensor and the bolt together, just to demonstrate that there is no an easy path between these two, meaning that they are two different leaks.

Below are the leaks that I've fixed in the past:

1. Valve cover gasket
2. Oil filter housing gasket
3. High pressure oil hose (from VANOS to the filter housing)
4. Oil drain bolt

I'm also planning to replace oil separator, its hoses, dipstick's O-Ring and the leaking oil sensor of course. Is there anything else that I've missed? Is there any indication that I need to replace the whole oil tank?

Here is an update for today 05/08
As planned, I went through oil separator replacement DIY today. Killed a lot of time, but it's completely worth it. Take a look at the oil hose going from the bottom of the oil separator to the dipstick tube. It's not broken, it doesn't have cracks, it's rotten. I didn't need to cut the hose as prescribed by DIY, I've simply pulled it a bit with my hands and teared it apart. The gray area on the attached picture was completely rotten, the other side connected to the dipstick was OK and I had to use a knife to get it off the metal pipe. We'll see if it fixes my problem. I've never seen hoses like that. Does anyone know what the reason could be? I always used BMW LL01 as my motor oil. I've stared adding ZMAX lately when change oil. Can ZMAX cause this kind of problem?

[Credelius]

Here is an update for this. I've replaced oil level sensor and dipstick gasket. I don't see oil drops on the garage floor anymore, but when I get underneath, I could still see that oil drop hanging on the bolt (see the first picture in my original post), so it's just a matter of time when I see it on the floor again. I've also decided to get rid of Zmax and changed oil recently.

My conclusion is that it's a slow leak through the oil pan gasket. Everything else has been replaced: VCG, filter housing gasket, high oil pressure hose, oil separator with all hoses, oil level sensor and oil dipstick gasket.

I read DIY for changing oil pan gasket and it looked scary to me when it comes to engine hanging on a special tool that I don't have.

Did anyone try to do this? Is it really that scary and risky considering that I'm not a mechanic and never was? As I understand, a dealer or any other professional mechanic would charge a lot for this procedure. Please advise. Is it a good idea to switch to "high mileage" oil? As I've mentioned, this car has 107K miles on it.

[Bigugly]

This isn't something for the average guy. It involves hanging the engine and dropping the suspension, yanking the differential and axles. If you don't have a lift and proper tools, this would be a very difficult DIY job.

[Credelius]

Originally Posted by Bigugly

This isn't something for the average guy. It involves hanging the engine and dropping the suspension, yanking the differential and axles. If you don't have a lift and proper tools, this would be a very difficult DIY job.

Thanks, very useful and this is what I thought as well. The leak is not that big - one drop on a floor in a couple of days. I will monitor it for now, if it increases will get ready ($$$) for a dealer

[Sterling Roadster]

I believe I have the exact same leak. I was quoted around 1000 to replace the gasket. With a higher mileage car, I really don't want to. I'm also curious if switching to high mileage oil could help. Currently running Liqui Moly motor oil saver, i'll update if I notice a difference.