Fuel Pump Care
 

I have a '79 200D (similar to the 240D), which runs like a dream. On the Fuel Injector Pump is a red cap marked OEL. Do I need to add oil to this pump? if so, what kind. Any advice would be helpful. I don't think this is the original fuel pump on this car.

Greetings from WMSBG
 

I know that my late friend's '69 220D had a procedure which was supposed to be followed every oil change, which consisted of opening a drain hole on the side of the injection pump and putting oil in the "oel" tube until it was clear that pure new lube oil and not old oil diluted by fuel was coming out the drain hole. I thought that they changed over to having the injection pump lubed by engine oil from the main pressure pump during the early or mid-70s, but I've only had to deal with 5-cylinder models after that '69, so perhaps yours still has the older style pump.