Leak from Oil Level Sender
 

1994 M104. I currently have a little leak from the oil level sender. Am planning to replace the 2 o-rings wt the next oil change. My question is if the engine is under a high load (85mph going up hill) could there be enough pressure in the oil pan to force a significant (like a few table spoons) amount of oil out of that seal?

http://www.pelicanparts.com/techarti...mall/Pic16.JPG (the image is from another pelican post not a pict of mine)

The higher the pressure the more oil will be moved through any hole.

I believe if there was any pressure the dipstick would pop out first. Typically there is no pressure in the oil pan (there shouldn't be). Likely has more to do with the oil being hotter, and thinner.

The oil pan has no pressure. In fact, its under a vacuum from the crank case ventilation system. Weak, but its there.

I've never worked on an M104, but on my M119, that oil quantity sensor plug is located just adjacent to the crank shaft. I wondered how oil could get out that tiny hole with it being so high above the pan. Turns out the hole is in perfect alignment with where the oil flying off the crank would probably hit. The attached picture is looking up at the sensor plug on the right side of the sump. I pulled the plug out slightly before taking the picture.

I have the same issue. Did u ever fix it. I replaced o-rings dry for two weeks. Leaking again. Seems to be leaking from the center of the sensor where the harness plugs!

Pictures

That happened to me, I replaced it and the new one did the same thing. Exchanged it for another new sensor and problem solved.

It is quite common as the center is plastic-ish and may develop cracks.

3 ways to fix it.

1) Cheapest way - use RTV to fill the hole and it should hold.
2) Cheap way - get one from JY. They are pretty much the same part # for most MBZ.
3) Expensive way - Replace.