...apparent oil/fuel leaks?

[khule-1]

I have an '87 300D-Turbo and it seems to be leaking oil/fuel in two places:
1. I believe its the fuel injectors (rope looking hoses); how often should these be changed and are they supposed to soaked with fuel?
2. There is a metal unit attached next to the lower portion of the engine. Mine is quite dirty with oil and I am not sure if it is leaking or maybe just a commonplace for sloppy hands to spill stuff. What is this unit and do I need to be concerned?

[pkmaven]

16 year old Mercedes tend to leave a signature wherever they go! When the car approaches 150k miles, the rear main seal and the front transmission seal fail. I would not trust anyone to replace these seals. Go to a few MB dealers and get a quote to replace both. They usually offer a package deal because to replace the front transmission seal requires dropping it down and out of the car. At his time the flywheel is exposed and must be removed to replace the crank seal (rear main seal). When the transmission is down have it checked for leaks and have the 16 year old vacuum modulator replaced. P.

[uwe]

The rope looking hoses are fuel return lines that go from injector to injector.
These frequently fail, and are very cheap to replace. They are pushed ona barb type fitting on the injectors. You can get a length of this hose from MB dealer and replace them yourself, just do one at a time. Also buy the cap for the last injector. You will see once you follow the hoses, the last one will have a cap on the unused barb fitting.
The mess you see on the bottom of your engine might be Diesel fuel seeping down, taking oil residue with it, looking like an oil leak.
I would first do the obvious, replace the return lines, and then take the car to have the engine steam cleaned. Only then can you tell where the oil is leaking from, if indeed it is leaking. A consciencous shop can also add flourescent dye to the oil and then use a UV light to detect leaks. Oil for Diesel engines takes a different dye. Diesel fuel also takes a different dye. This is especially helpful in diagnosing expensive repairs, like those suggested by pkmaven.