Identify this part and oil leak, picture game.

I found this small part on the plastic splash guard from under the front of the car. I haven't seen anything like this anywhere. The car has recently had the cooling system rebuilt just prior to me getting the car. It is hollow made of something that looks like brass and has a rubber boot.
Also the oil seeping out of the engine cover bolt. I assume it is going to be a valve cover set. I searched the forums, I promise I did BlueB, and was unable to find the problem discussed.
My search abilities are in their developmental stages.
The car runs great.

Originally Posted by dlfred530i

I haven't seen anything like this anywhere. The car has recently had the cooling system rebuilt

It's probably a broken expansion tank nipple:
- How to prevent the common broken expansion tank nipple mishap

From this Behr cooling system autopsy thread:
- Behr radiator and Behr expansion (aka surge) tank autopsy (1) (2), here is a pic of me trying to cut the oetiker clamp off the expansion tank nipple.


Snap! The nipple broke right off. The inside metal sleeve is intact; but the plastic corrugated nipple itself sheared off the expansion tank (ruining the tank in the process).


It's hard to see in this light but to the left is a new expansion tank with the nipple intact; to the right is the old expansion tank with the nipple broken off.


The broken corrugated plastic nipple is inside the hose in this picture. The metal sleeve is inside the nipple in the new expansion tank; but you don't see that because it's a cylinder liner inside the plastic nipple (I presume to prevent this from happening!).



To the OP:
Please do us a big favor and slice open your old (now ruined) expansion tank and let us know what the POSITION of the black slider is:
- Request for an expansion tank autopsy to understand the black slider (1)

Originally Posted by bluebee

It's probably a broken expansion tank nipple:
- How to prevent the common broken expansion tank nipple mishap

Correct!! I have the same piece taped to a receipt for a new expansion tank! lololol

This is how my tank failed and broke that nipple off.




This is from the Bleed screw failure

Originally Posted by Whorse

I have the same piece taped to a receipt for a new expansion tank!

The OP did say the corrugated part was 'rubber' (while the expansion tank is plastic) but I agree; it's the most likely part.

BTW, I'm going to put your pictures in the cooling system pictorial failures thread as you break the same stuff that I do!
- Pictorial look at typical E39 cooling system failure modes (1)

To the OP, on the topic of the oil seepage. Last night, in the dark of my garage, I replace my spark plugs and found a bit of oil seepage near where yours seems to be:
- Pictorial DIY for an M54 spark plug replacement on a 2002 BMW 525i E39 with 95K miles

Since I also had oil seepage near the #1 cylinder, I looked for WHERE it could be coming from; and, for the life of me, I couldn't figure it out.

Where 'do' you think that oil seepage is coming from in your photo?

Here is a (sorry it's dark) shot of my engine covers removed and the coils & plugs removed:

Looks like the oil is seeping from the oil cap, Or a couple of drop fell on the valve cover when somebody added oil. Does it reappear after you wipe it off?

Originally Posted by Whorse

Looks like the oil is seeping from the oil cap, Or a couple of drop fell on the valve cover when somebody added oil. Does it reappear after you wipe it off?

Interesting. I changed my oil, oh, about two weeks ago. Maybe I missed a bit.

There 'is' oil BELOW all that.

Lot's of gunky oil all over the front passenger side of the engine (about where the VANOS sits). I presumed 'that' was from the VCG leaking (which was put on my list waiting for the round Tuit).

Funny thing, it doesn't 'drip' on my carpeted garage. Nor am I 'losing' oil that I know of. So, whatever is making that mess on the side, is splattering it about more so than leaking it out.

I didn't even think to wipe it off so I won't know if it reappears under the coil. But it "does" reappear on the outside, under all that, by the VANOS (and above that shiny SAP thing).

Note: This is a picture I took of the oily grime below that area in August of last year. I cleaned it off at that time but it comes back, only not nearly as thick as it originally was in this picture below. Ignore the question in the pic

I also forgot to mention that when my expansion tank blew its top it also took out my fan shroud along with that nipple. Must of been alot of force to do that. Cant wait to get my valley pan done so i can switch to Evans coolant

Nice call and very quick. It looked as though the expansion tank was new. Explains that. I will try wiping the area again but I believe that I took care of it recently when I was cleaning up under the hood. I will give it another shot. Surprised that oil situation wasn't an obvious one. Thanks again for the part ID. I will report back in a day or so about the oil in the bolt/ recessed area.