Possible oil leak/seepage under corner of engine

I own a 2001 330i with 95k and love it, just like you guys
However, I've recently (about 1.5 weeks ago) noticed an oil leakage right beneath the bottom left corner of the engine. It seems odd because around the leak seems to be electrical connectors.

I've attached pictures (my key is pointing at the location) Sorry pictures seem to be rotated. However, the front end of the car is on the right side. This is at the lower left of the hood of the car.

Anyways, any suggestions in defining the problem? All help and time devoted to help me is greatly appreciated. And here's a "thank you" beforehand. Thank you.

it seems u have a VCG leak or the CPS has a failing O-ring.

I actually believe I might have a vacuum leak because my car idles roughly at times, especially when cold. And SES is on with lean bank 1 and 2. Does this have anything to do with it?

nope not related.

Originally Posted by SamxK

... I've recently (about 1.5 weeks ago) noticed an oil leakage right beneath the bottom left corner of the engine. ...

To reduce confusion, the correct way to describe the location you are pointing to is the front, right side of the engine at the top.

With a car, right is always to your right when you are sitting in the car facing forward. If you are in front of the car looking back at it, the right side of the car will be to your left.

I would pull the Camshaft Position Sensor and install a new O Ring, it appears to be leaking.

Originally Posted by tcphoto

I would pull the Camshaft Position Sensor and install a new O Ring, it appears to be leaking.

We covered all the o-rings you may need for an M54 over here:
- Let's create a list of o-rings (by size & by part number) to buy when ordering parts

Excerpt below:

Originally Posted by doru

CPS to engine O-ring p/n 12141748398 (Item #9)




CPS O-ring (Intake & exhaust) p/n 12141748398 (Item #6)

EDIT: M54 CPS locations are in this thread.

Originally Posted by joegr

To reduce confusion, the correct way to describe the location you are pointing to is the front, right side of the engine at the top.

With a car, right is always to your right when you are sitting in the car facing forward. If you are in front of the car looking back at it, the right side of the car will be to your left.

Thank you for this information. I will remember the next time I locate something.

So it seems like I have a worn exhaust side CPS O-ring. would replacing that be difficult?
I took a look and it seems like space is very limited around that area

Looks like CPS o-ring, but just as an alternative, could be seeping from an electrical connector itself. It's been known to happen. Ask me how I know...
http://www.bimmerfest.com/forums/sho...d.php?t=569509

There are multiple videos posted on YouTube and I found them very helpful before I replaced both exhaust and intake sensors. It makes it much easier to do the exhaust side when you remove the mechanical fan and shroud. It only takes a 5mm Allen wrench and BMW recommends a new fastener and o ring when doing the sensor. I saw a thread that talked about oil leaking through the sensors connector, I would find it, read it and compare to your vehicle.

Originally Posted by tcphoto

There are multiple videos posted on YouTube and I found them very helpful before I replaced both exhaust and intake sensors. It makes it much easier to do the exhaust side when you remove the mechanical fan and shroud. It only takes a 5mm Allen wrench and BMW recommends a new fastener and o ring when doing the sensor. I saw a thread that talked about oil leaking through the sensors connector, I would find it, read it and compare to your vehicle.

Thanks for your help. I've looked on YouTube to find out how to remove the Exhaust CPS in order to replace the O-Ring and couldn't find any helpful DIY videos. May I request that you provide me with a link for one? Having to remove the fan and all that seems complicated and I would like to know the big idea of what I'll be doing before I order the parts and start. That would be great if you could. Thank you

[QUOTE=bluebee;7332243]We covered all the o-rings you may need for an M54 over here:
- Let's create a list of o-rings (by size & by part number) to buy when ordering parts

Wow awesome, thank you for pointing out the part and a possible solution to my problem! With the four pictures you provided, can I say that I have an Exhaust CPS O-Ring failure? I only understood one of the pictures. We're the pictures pointing out the different CPS's?

Originally Posted by SamxK

We're the pictures pointing out the different CPS's?

Yesterday, I clarified (and colorized) the realoem diagrams in that M54 engine thread - but you might not have seen it yet.

Originally Posted by bluebee

• 11 Engine > 11 15 Cylinder Head > Cylinder Head Vanos
  • # 06 Intake CPS O-ring 17mm ID x 3mm thick 12141748398 $1.20 <=== for the camshaft
  • # 06 Exhaust CPS O-ring 17mm ID x 3mm thick 12141748398 $1.20 <=== for the camshaft
• 11 Engine > 11 10 Engine Housing > Engine Block Mounting Parts
  • # 09 CKP to engine O-ring 17mm ID X 3mm thick 12141748398 $1.20 <=== for the crankshaft

All the o-rings in the above post look like this:


And, here's the original pictures of this thread, as used in that o-ring thread:

Originally Posted by SamxK

I actually believe I might have a vacuum leak because my car idles roughly at times, especially when cold. And SES is on with lean bank 1 and 2. Does this have anything to do with it?

If it is indeed a CPS or VCG leak, they could indeed be related. Anything leaking oil out can easily let air in. Any difference in air volume between what is measured at the MAF and O2 sensors can trigger SES codes.