Diesel Fuel Injection Pump Lubrication

[Diesel240D]

Could some elaborate on a 1975 Mercedes 240D injection pump lubrication

[Palangi]

It has a filler cap labeled "OEL". A couple inches below the cap on the side of the pump there is a removable plug. Unscrew the plug and add oil (ordinary motor oil) until it runs out the plug hole. It takes only a small amount of oil. It is good to do this occasionally as the oil will get a bit of fuel mixed into it.

Note that this only exists on 115 and earlier cars. It does not exist on 123 or later cars.

[Diesel240D]

Originally Posted by Palangi

It has a filler cap labeled "OEL". A couple inches below the cap on the side of the pump there is a removable plug. Unscrew the plug and add oil (ordinary motor oil) until it runs out the plug hole. It takes only a small amount of oil. It is good to do this occasionally as the oil will get a bit of fuel mixed into it.

Note that this only exists on 115 and earlier cars. It does not exist on 123 or later cars.

Thanks Palangi

[Lycoming-8]

Years ago, I was told to syphon out the old diesel diluted oil that was in the pump before adding new oil. Seems to make sense that you would not want the diluted oil in there any longer. The new oil would not be able to magically displace the old stuff, especially with the only drain being a hi level overflow.

[Palangi]

Originally Posted by Lycoming-8

Years ago, I was told to syphon out the old diesel diluted oil that was in the pump before adding new oil. Seems to make sense that you would not want the diluted oil in there any longer. The new oil would not be able to magically displace the old stuff, especially with the only drain being a hi level overflow.

That is probably a good idea, especially on one where you don't know the history.

[lietuviai]

How do the newer pumps get lubricated?

[aklim]

AFAIK they have been engine oil lubricated since a long time ago.

[lietuviai]

I've never examined one to see how they were hooked up to the lubrication system. I became curious about it when this thread came up.

[nhdoc]

Originally Posted by Palangi

It has a filler cap labeled "OEL". A couple inches below the cap on the side of the pump there is a removable plug. Unscrew the plug and add oil (ordinary motor oil) until it runs out the plug hole. It takes only a small amount of oil. It is good to do this occasionally as the oil will get a bit of fuel mixed into it.

Note that this only exists on 115 and earlier cars. It does not exist on 123 or later cars.

This comes as news to me...I had driven a '74 240D 170,000 miles and never knew to do anything to it other than change the oil in the crankcase. I must admit I never did a valve adjustment and never, ever added or changed any oil in the IP...hmm...I was young and ignorant then though.

There is a small black tube running to the inner side of the IP. The oil gets pumped into it and runs out through the timing chain hole.

[Palangi]

Originally Posted by nhdoc

This comes as news to me...I had driven a '74 240D 170,000 miles and never knew to do anything to it other than change the oil in the crankcase. I must admit I never did a valve adjustment and never, ever added or changed any oil in the IP...hmm...I was young and ignorant then though.

Actual fact is, a lot of owners never knew about it, and I have never heard of a pump failing from lack of oil. It's just one of those old MB anal maintenance things.