I have an 85 300SD with 115k on it. I also have an oil leak in the front of the engine that looks like it is coming from a bolted on thing that I don’t know what it is. It is a cylindrical thing that is about 3 inches and sticks out from the front of the engine. It sits to the driver’s side of the water pump. (At least I think it is the water pump. It is connected to the fan. Also, is there a water pump gasket or seal since we are going to take out the radiator and all that to get to the other thing, I thought we could deal with that at the same time.)

__________________
Dave

85 300SD with 150k

Do you have a photo of what you are referring to? I would be reluctant to start taking things apart until you know what you are working on. Are you talking about the vacuum pump?

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1CQ0J3JZ41TN1E0BC1&year=1985&make=MB&model=300-SD-002&category=All&part=Diesel+Vacuum+Pump

Aha!! It is the vacuum pump. Now I know what that part is. I don't think I need a new pump, just a gasket or seal.

Would a leaky vacuum pump cause a loss of power?

Thanks,

__________________
Dave

85 300SD with 150k

You can just buy the gaskets:

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1CQ0J3JZ41TN1EN1LX&year=1985&make=MB&model=300-SD-002&category=All&part=Vacuum+Pump+Gasket

You can also buy a rebuild kit.

What are your symptoms? Is this just an oil leak, are you losing vacuum, are you losing engine power? An oil leak at the vacuum pump is not related to a lose of engine power, unless there is something else going on.

Actually the leak has been there a while and I will replace that gasket this week.

I have been experiencing a loss of power. When I am below 2000 rpm's, there is very very slow acceleration. When the turbo winds in, there is more acceleration but when I let up on the gas, the engine goes back under 2000 and there is no power again. So I experience slow acceleration followed by a quick burst from the turbo which causes a shift of gears which drops the rpm's below 2000 which causes the engine to lag which then causes me to put my foot down more which starts the whole thing over again.

This just started happening a week or so ago. I have read something about the banjo bolt being cleaned but I have yet to find a good manual that will show me a picture of this banjo bolt so I can find it to clean it.

__________________
Dave

85 300SD with 150k

Also, if I have the vacuum pump off to replace the gasket, should I buy the rebuild kit and do that too?

__________________
Dave

85 300SD with 150k

It's worth cleaning the banjo bolt, but I'm not sure that's your issue if you have good power with the turbo. The banjo bolt is located at the rear on the intake manifold. It provides a pressure "signal" through a line that tells the injection pump to provide more fuel when there is turbo boost.

I would do some searches on power loss. One way to recover low-rpm power is to adjust the ALDA, but if this started suddenly, you should look for the "real problem" instead of just the symptom.

Thanks. It did start suddenly. I am probably going to take it to a mechanic but I wanted to see what I should look out for. I am so new at this that I want to learn more before I get too far into it.

I did some searching last week but I couldn't seem to find anything conclusive. I will look again.

I noticed that you are from Parker. I am in NW Denver. Small world, eh?

__________________
Dave

85 300SD with 150k

Lose of power issues are tough because everything has to be correct for them to have good power at low rpm. The usual advice is to check "everything" (fuel filters, valve adjustment, injection timing, etc.) before you mess with the ALDA.

There are about 5 or 6 regular forum members from around Denver.

Thanks for your help. I'll let you know how it comes out.

__________________
Dave

85 300SD with 150k