Well here's my story: I come from a long line of Chevy guys, but about 2 years ago, I started getting into MB. I love these things...I'm already on my 3rd one. 1993 400e, What brings me to this post is:

1) low oil pressure at idle

I've been through the forums, and my first thought is the pressure relief valve. One problem, though, is that I don't know where this is. In order to help me search more efficiently:

2) is this also known as M119?
3) is there a place I can get a breakdown of the engine oil system on this car?

The problems started with an orange light on the dash with the picture of an oil can over the symbol for liquid like this...sort of:



So I changed the oil. I don't have an owner's manual, so I used my best guess for type and went with Mobil One 10W 40:

4) where can I get an owner's manual?

The light didn't go away, 2 months went by, and now the red check engine light is constantly lit, and the yellow information light comes on when I'm at a stop light. I was trying to go through this without making a post, but now my eyes are crossed from all the reading!