I have a 1996 W210 E300D that won't start. About a month ago I had a check engine light and the glow plug light stayed on after starting for a few minutes.
I checked the glow plugs and 2 were bad. Week before last I changed all 6 GPs and re-installed the intake. The car would not start. The engine would crank and fire but shut off when the key was returned to position 2.
I pulled the manifold back off and discovered that the wires to the coolant temp sensor were bare for about 1-2 inches and that several of the wires had shorted together. I checked the temp sensor (OK) and separated and taped the bare wires. I even un-taped the harness for about 1 foot in either direction from where the wires to the temp sensor exited. the insulation on some of the wires were cracked but had not come off. I taped all of the cracked wires and re-taped the harness, re-installed the manifold.
A friend suggested that I may have activated the anti-theft feature of the alarm so I manually locked/unlocked the drivers door.
The car started right up and did so 20 or 30 more times. I drove for about 30 miles and parked. The car continued to start no problem.
Two days later the original non-start problem reappeared and 3 days later is still there. I am getting no OBDII codes or other lights.
Does anyone have a clue?

Jim