oil is coming though my vaccume lines!! help - PeachParts Mercedes-Benz Forum

anarchy · #1 05-28-2009, 05:10 PM

so I was driving down the road and noticed that there is black oil leaking from under the steering wheel at closer inspection I noticed that the vaccume lines for turning the engine off were leaking oil, and also no longer did the car turn off normally. I removed the main line from the vac pump and inspected it. Seems to be working just fine doesn't seem to be delivering enough pressure though. and i also removed other vac lines and found oil in them........now heres where it get really wierd....I recently installed an cold air intake I also bypassed the recirculation valve and hooked it straight to the pipe that goes back to the engine. I was running the engine and removed the oil cap to find that it had excess pressure built up so I disconnected the pipe. Would it be possible from excess pressure to some how brake my vac pump or to force oil into the vac system???? help please....

pawoSD · #2 05-28-2009, 05:24 PM

The stock MB air intake is a cold air intake. I bet you installed one of those pointless K&N Cone filters right? Bad move. All it does is make the engine suck in hot air from the engine compartment and excess dirt. Put the stock system back on!

You have oil in your lines because the vacuum shutoff valve has a ruptured diaphragm, which is why the car will no longer shut off properly. That will need to be replaced, as well as the lines cleaned or replaced.

toomany MBZ · #3 05-28-2009, 06:05 PM

Quote:

Originally Posted by pawoSD

The stock MB air intake is a cold air intake. I bet you installed one of those pointless K&N Cone filters right? Bad move. All it does is make the engine suck in hot air from the engine compartment and excess dirt. Put the stock system back on!

You have oil in your lines because the vacuum shutoff valve has a ruptured diaphragm, which is why the car will no longer shut off properly. That will need to be replaced, as well as the lines cleaned or replaced.

Yep, what year?
The vac pump on older models can cause similar problems.

anarchy · #4 05-28-2009, 07:03 PM

yes I will definitely put the old one back on, I need to get it re welded though all the mounts are broken that why I replaced it, It was just rattling around all the time. But im still very confused on how oil was in my vac system and it wasn't just a few drops more like a half quart...

anarchy · #5 05-28-2009, 07:05 PM

edit: where is the vaccume shutoff valve? obviously not the one Im looking at its on the IP so theres no way It could get engine oil in it.

toomany MBZ · #6 05-28-2009, 07:14 PM

Follow the brown with purple stripe vac line, that's it. You won't see any oil on the out side.
The air cleaner mount/s break, that "Y" thing and the three buffers.

theshadyguy · #7 05-28-2009, 07:14 PM

You can order a new bracket and mounts from Phil for your air filter housing. They were pretty cheap and way easier than welding, imho!

anarchy · #8 05-28-2009, 07:26 PM

yeah i disconnected the lines and there was oil in them, also is it bad to have the EGR valve disconnected with no blockplate installed?

jkubica · #9 05-28-2009, 08:53 PM

Quote:

Originally Posted by anarchy

so I was driving down the road and noticed that there is black oil leaking from under the steering wheel at closer inspection I noticed that the vaccume lines for turning the engine off were leaking oil, and also no longer did the car turn off normally. I removed the main line from the vac pump and inspected it. Seems to be working just fine doesn't seem to be delivering enough pressure though. and i also removed other vac lines and found oil in them........now heres where it get really wierd....I recently installed an cold air intake I also bypassed the recirculation valve and hooked it straight to the pipe that goes back to the engine. I was running the engine and removed the oil cap to find that it had excess pressure built up so I disconnected the pipe. Would it be possible from excess pressure to some how brake my vac pump or to force oil into the vac system???? help please....

Hi

You don't give your car's info - but if you have the older style vacuum pump that uses a diaphram - it can rupture and let engine oil into the vacuum system. The good news is that the repair kits are cheap and the rebuild not too difficult.

Joseph

mplafleur · #10 05-28-2009, 09:00 PM

I'd say there is a leak in the diaphragm in the vacumm shutoff valve in the injection pump. It is pulling oil from the pump into your vacuum lines.

anarchy · #11 05-28-2009, 10:08 PM

so yeah its an 82 300SD, and I think I figured it out, i bypassed the recirculation valve and just hooked the tube right back into the engine which caused backpressure, enough to pump oil back though my failing vac pump. and also at the same time I found out that my radiator is leaking and my fan is messing a blade so the clutch is bad now. anyone have parts for sale>?

toomany MBZ · #12 05-29-2009, 08:04 AM

The '82's I had (616 & 617) didn't have that vac pump set up.
Yes, you can just plug off the egr system leaving it in place. I did pull the vac lines from the black box tho.

anarchy · #13 05-29-2009, 11:11 AM

yep i have completely taken all that stuff off I just didn't really know what really could be removed with out messing the vac sys up, Im thinking I gotta adjust my transmission now because it likes to shift late and slam into gears some times mostly if im flooring it.