On my 1998 MB e300 Turbo Diesel I have a small oil leak on my fuel injection pump. The engine oil drips from the the access plate (between the gasket and or plate and the pump housing) on the underside of the diesel fuel injection pump. I have installed a new plate and screws along with the gasket twice and still can't stop the leak. I also added Lubo Moly Engine oil stop leak which has slowed the leak down, but not stopped it. I lose about 1 quart of oil a month with this problem. I don't think it is blow by because I have straight compression (360 PSI +- 5 PSI) across all 6 pistons. I also checked the crankcase ventailation (negative air pressure) system and it appears to be in good order. Has anyone in our group encountered this problem? I'm trieing to solve this without having to remove the injection pump from the car (labor guide says 8+ hours with speciality MB tools). Herb

 

I've been fighting oil leak on older MB diesels for long time. Some mechanics even says, that those engines are DESIGNED to leak
Anyway, I was able to access the injection pumps without removing them. One was having loose nut on mounting bolt. Took some time and dirty hands, to reach the nut from under the car, having space for 1/12 turn of the wrench.
On another pump (92 - 2.5l) the pump covers had o-ring cross-section gaskets, that over the time deteriorated. I was able to remove the covers and re-install them with copper sealant.
In worst to deal with leaks, I used polyurethane caulk (Home Depot) over the cleaned surface. It looks messy, but stops gravity leaks.