85 300D: Engine oil in ignition lock housing??!!! - PeachParts Mercedes-Benz Forum

rbc · #1 09-07-2009, 01:53 PM

So my ignition lock failed, and in the process of taking it out of the car and then apart, I found engine oil in the main ignition housing behind the electrical ignition switch when I removed it from the housing. It's right near where the vacuum lines attach. Not alot, but enough to pool.

Any ideas for where this came from and how I should remedy? There also seems to be a fuel leak around the fuel filter -- just dirty everywhere. Dont know if it's related. Something is not right and I would like to correct it while I have the instrument panel off, etc.

Thanks.

zeke · #2 09-07-2009, 02:18 PM

It comes through the vacuum lines when there is a failure somewhere in the central vac system.

I just replaced the one in the wagon this weekend b/c the oil in there (not much, but enough) mixed with dust and made a paste that bound it up. Of course I had replaced the cylinder first, without replacing the lock housing, so I got to dremel it out when it bound up the second time.

Soooo, replace the housing while you can do it easily, but also make sure your vacuum system is in good working order!

good luck!!!

kerry · #3 09-07-2009, 02:22 PM

Caused usually by a failed shut off diaphragm. If your engine is shutting off ok, chances are it came from a failed shut off diaphragm what has since been replaced. Also could come from a failed vacuum pump diaphragm but I think you have a piston pump and not a diaphragm pump.

Cr from Texas · #4 09-07-2009, 04:38 PM

Do a search on adding a fuel filter to the vacuum lines. I believe once you get oil in a line there will be a slug of oil moving around until you remove it. The filter (horizontal) gives it a place to reside and be removed. I have three on mine: IP cut off line, transmission line, and vent line.

rbc · #5 09-07-2009, 07:42 PM

Interesting. Shut off seemed a second delayed (before the ignition broke), but it was shutting off. I have not done anything to the shut off diaphragm, but someone doing the engine mounts for me messed with the vaccuum (i know only because I disconnected the vac from the lock system and I think he reconnected it). Is there any way to pinpoint whether this is an old or new problem?

toomany MBZ · #6 09-08-2009, 10:06 AM

Pull the line at the shut off actuator, see if there's any oil there. The actuator may be a bit shinier than you would think, that may be a clue to it's age. AFAIK, you can't pull it apart to check for a torn diaphragm.
You'll see the different color metal on mine, it has been replaced.
The second pic is of the old one.

rbc · #7 09-08-2009, 11:42 AM

Just for the sake of clarity -- i.e. to make sure I dont miss something obvious -- you mean the top line shown in the picture correct?

toomany MBZ · #8 09-08-2009, 12:46 PM

The top line coming from the white round plastic item is the Vacuum Control Valve, not that. Just below is the shut off actuator, there is a black rubber connector, it's bent over, but visible. That fits on a brown hard line that goes to the ignition.
Here's a view from lower down, the VCV is just above, you can see the brown hard line going to the black rubber connector and its proximity to the oil filter canister.

rbc · #9 09-14-2009, 11:16 AM

So I finally got to this. Thanks for the guidance. I pulled the vac line and there was a slight bit of oil on the lip of the vac line. But nothing in the line when I evacuated it with air. I guess I should monitor this? I am little confused about where people are putting those cheapo fuel filters to monitor this. Should I put one between the shut off actuator and the ignition lock housing?

toomany MBZ · #10 09-14-2009, 06:15 PM

If the shut off actuator doesn't seem to be newer than the rest of the engine, you probably need a new one.
Yeah, install one of those paper filters between the shut off actuator and the ignition switch, keep an eye on it.

rbc · #11 10-17-2009, 02:28 PM

Ok, now the car shuts down on a full 1-2 second delay. There is a dolop of oil in the vac line when I pull it (pulled it at the top of the rubber connector). So this is a shut off actuator you think? I am checking for replacement procedure now but if anyone has an easy "go to" for this, I am all ears.

toomany MBZ · #12 10-17-2009, 02:49 PM

Sounds like a failing actuator to me.
You may need to get an item or two out of the way, but there are four screws holding it on. Once you have removed those along with the holding ring, it comes right out. Note the orientation of the hook. Put the new one in just like the old one came out, install the holding ring with the four screws, hook up the vac line. Done.

rbc · #13 10-17-2009, 02:49 PM

Oh, and one more thing. The car went from a perfect starter to a PITA to start right around the same time. When I pulled the van line to the shutoff actuator to check for oil, there was a puff of vac in there. Is this residual vac? If so, is this the residual vac problem that causes hard starts (because it tells the IP to starve?)? Are these probs linked?

toomany MBZ · #14 10-17-2009, 02:57 PM

The shut off actuator needs vacuum to shut off the fuel, so if the key was off that's normal. So you have a FAILING actuator, meaning you'll have a bit of vacuum.

rbc · #15 10-18-2009, 10:35 AM

Thanks. The one thing that confuses me about replacing the thing is how to choke the engine (at the turbo inlet) in case the actuator is installed in reverse. In other words, you can blow your engine to smithereens if it's reversed. DYI says just put a spray paint cap over the turbo inlet and the engine will stall. I want to understand this before i do this job -- just in case. Better safe than sorry. any thoughts?