Oil in Air Cleaner Box
 

I opened the air cleaner box on the 84 300Sd to track down oil all over the top of the strut mount, the box is directly over the mount. There is a drain hole in the box, its seems that is where the obvious oil is coming from.

There is quite a bit more oil than usual in the box. What might be the usual suspects for that?

Excessive oil from the breather tube (between valve cover and air filter box)?

This was passed from the late Dr. Marshall Booth on an email list I subscribe to:

---------------------------------------------------------------------------------
> The late Randy Durrance documented the "official" MB fix some
> years ago.
>
> > This is usually done when the valves get adjusted. Pull
> the valve cover off and look at the front edge of the oil baffle plate where it meets the inside of the valve cover close to the oil cap and breather. If it has been fixed, you'll see a gray epoxy covered area. If it needs fixing, you'll see about an eighth inch gap. Clean the area with brake-clean and apply epoxy.

Don't use RTV. Don't use J-B Weld (it takes too long to dry and will ooze through the gap. The official stuff was Lock-tite/NAPA 5-minute epoxy. It does an excellent job and is oil resistant. We used to do this at the M-B dealer in the 1980s. It paid an additional 2 tenths of an hour to do the job with a valve adjustment.

Regards,
Randy D.

Make sure that you have the revised flat one piece hose that connects the valve cover vent to the air cleaner and not the 3 piece original one. It's inexpensive - maybe $12 last time I checked.
---------------------------------------------------------------------------------

Thanks Max. I was planning on adjusting the valves soon. It does seem to be coming from the breather tube.

The oil no doubt comes from the breather.

But on the 84 SD, doesn't the air cleaner have a cylindrical separator in the center that separates the oil and allows it to return to the engine? There should be a pipe coming off the bottom that connects to the block/sump.

If you are getting oil on the inlet side of the filter, then maybe the separator is not draining?

On my 85 300D, we switched to an earlier (82?) engine that did not have the sump connection. As a result, that cylindrical separator fills with oil. Some of it no doubt goes back to the engine with the air. But when I do an oil change, I can always suck out a cup or so of oil from the separator (outlet at bottom is plugged)

I looked at my spare valve cover and took some photos. Is this the gap that needs to be filled with epoxy?

http://nemitz.net/images/valvecover.jpg

if oil is getting into the filter area, the lid of the seperator in the air cleaner needs to be sealed as well.

also, if oil is leaking on the mount below the air cleaner, the o-ring on the nipple to the drain tube ls failed, and needs to be replaced...

I'm not sure about the gap.

Yes.