I am thinking about buying a diesel car to run homebrewed biodiesel. Mercedes and VW are the only cars i can think of plentiful in Texas for this type of project. I am leaning toward the Mercedes.
I am thinking about a 1980-1985ish. Is there anything I need to beware of in these years or an option I need to find? What kind of mpg are these rated at? Finally are there any websites out there that tell engine and trans specs for the differnt years. Maybe one with common problems and DIY type upgrades. I tryed searching but I didnt see what I was looking for.

 

The 123 model MB's with OM617 turbo, are a great choice for biodiesel, or veggy!

Aside from normal maintenance, valve tuning needs to be done on these engine from time to time. Great cars, and if cared for should go well past the 300K mark! Just don't by a cheap one that needs everything, you'll be disappointed! Look for receipts, one that has been maintained.

 

Did mercedes use a mechanical style injector pump in the early 80's? If so when Did they swap to the electronic style pump?

 

Injection pumps (mechanical) were used up to 95 at least, don't know much about MBZ's newer than 95! After 95, lots of changes and more towards system computer management. Sealed (lifetime) transmissions, that have no dip stick to check fluid, etc. The new MBZ's are not DIY friendly and also suffer inferior quality.

It is many's opinion that MB quality stopped at the end of the 1995 production run. The next generation MBZ's began in 1996, and with fierce competition from Japan, MB was forced to make changes. They don't build them like they used to!