W126 mystery oil leak
 

Drivers side steering knuckle/ball joint/brake shield area has some type of fluid residue (oil and crud, fresh and old)). It does not look like brake fluid more like oil. I am not loosing any brake fluid in the resevoir or brake pressure so I do not think it is a brake line or fitting. Oil pan gasket seems to be seeping a bit, the usual oil cooler line fittings, turbo drain seals, air cleaner seals are leeking oil, could this be throwing oil onto the the steering knuckle area while driving? Can not see anything while sitting still and running. Also fresh oil is on the bottom of the R4 radial a/c compressor. Any ideas? Thanks

check to see if the A/C lines are leaking (clean them and observe ). Since the manifold threads on to the A/C compressor in the lower front area of the enigne compartment this could be the culprit.

This also means that your pressure cut-off switch (located behind the drivers headligt) is faulty

power steering and/or oil cooler lines
 

Could be power steering, both of mine leak a little but I notice it on the glow plug relay not down where you are mentioning.

What about oil cooler lines? They are sometimes hard to see leaking and since the thermostat that controls the flow to the cooler does not open to the cooler unless you are running down the road then the oil does not drip straight down but gets thrown back by the wind.

Check around the metal crimp fittings on the cooler lines to see if there is any sign of oil there.