Check of oil around the valve cover gasket and filler (athough I'm sure there is plenty there from spillage at the moment!). Clean it all up and then drive it to see if more accumulates.
Valve cover gasket is easy to change -- pull the plug wire tray out (tape it together to keep the wires in place), then remove the screws (six, I think) that hold the cover down. Wriggle it out, then pull the gasket off. Probably rock hard with cracks all along the sealing edge, they die pretty fast in this particular engine.
Clean the seating surface with solvent -- it must be completely clean and dry, no oil or dirt. Install the new gasket on the valve cover -- it just presses on, no sealant, please.
Wriggle cover back into place, then double check gasket installation on cover to make sure it isn't rolled over somewhere. Lift cover slightly and thump it down on the head, repeating until it makes a solid "clop" indicating the gasket is all the way onto the cover. You'll hear it. Re-install screws and tighten gently, great pressure will only cut the casket or warp the cover.
Also, wipe the filler cap and opening completely clean and watch for seepage -- if the gasket has a groove in in, it will leak, up to a quart in 500 miles. Ditto for a missing gasket here.... New ones are cheap, so is a new cap. Make cure most of the oil consupmtion.
These engiens run so clean, by and large, that the oil drops are clear from leakage, not black -- took me a while to notice them in my gravel drive!
Door panel comes off as follows:
Carefully remove the power seet switch knobs (front door) -- they pry off. Don't drop the headrest knob, it will vanish. Pry off the black plastic covers around the top of the armrest, rear part first. They just snap in. Push the black plastic "cup" that holds the door latch lever forward until it unclips, the use a small screwdriver and lift the operating rod out of the lever. Remove latch lever assembly.
Remove the screw at the top of the armrest (10mm), the two screws at the latch plate and the latch plate trim, and the lock button. On rear doors, remove the ash tray and the trim behind, it prys out top first (I think). On front doors, remove the triagluar trim at the front window bottom corner. Be carefull, the top clip usually breaks off. You will likely find some adhesive holding it on instead. You can leave it loose on the mirror lever on the driver's side.
Pull door panel STRAIGHT up, do NOT pry outwards on it (I found the remains of the hooks in the TE where someone pried out and broke them). There are four or so plastic hooks that hold the panel on. Watch for wires, there is usually a lamp in the bottom of the door, and speaker wires up front. You can leave them hang if you are carefull.
Peel the plastic liner back. Door check is held on by three screws, one behind the panel and the other two on the front outer edge of the door. The strap is held on by a pin with a retainer clip on the bottom. Push the clip of and carefully drive the pin up and out with a small hammer. Remove screws and pull check out.
You will find, usually, that the side screws is loose -- mine was completely out on the 300D -- and the resulting stress has broken the 'ears' off the check, or that the spring inside is broken and the large ball bearings are in the bottom of the door. Either way, clean up any bits so the don't rattle, and install the new check. On the front doors, make sure you get the vac and wiring lines in the right place, they tend to get between the check and the door at the front. Tighten the screws up, and re-install the plastic sheet and door panel. If the plastic is in back shape, replace it with antoher pieces of heavy plastic sheet, cut to fit. 3M adhesive works great to hold it.
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!