oil in air filter and what are these parts?

[PutPutPut]

Hello,

Car: 1984 300sd turbo diesel
Mileage: 300k+ (odometer broke 4 years ago)

Took our the air filter to replace, and saw oil all over the inside. See picture. Is this okay? I searched the forum for "oil air filter", 9 pages of results, but nothing jumped out. Picture, see the oil running between 7 and 8 o'clock? Also that stuff in there is all oily..


There was a post where some guy with a 240d had oil around the tube thing that connects the air filter area to the engine.. his had same oil gunk like mine. This gunk exists both over the engine and the top of the air filter cannister thingy. One more:


FYI, I am new to all this, first time ever actually spending time under the hood of a car. Yesterday I flushed the power steering, that was fun I have the dash out and am waiting for the odo gears to arrive for replacing, and like a ding dong, I painted the faded-yellow needles to "tequila sunrise" orange color nail polish. In the middle of changing the oil now, that plug in the bottom sure was stuck on pretty hard, but after some grunting and brute force, it came loose.

While under there, I noticed quite a bit of oily residue. What are these two parts? The first I'm looking from under the driver's side wheel towards the front, I guess by the radiator? It was very oozy and gooey, what is it?


And when I looked towards the back, there's this cannister thingy that was also oozy. What part is it?


I appreciate your time and help!

The car was purchased new by my parents, then after college became my daily driver for many years. Last year it I purchased a new car, and now I just use the diesel to go surfing (cosmetically neglected), we still try to drive it at least once every other week. Thought this would be a great opportunity to learn more about cars in an attempt to do basic maintenance, and who knows, I've been toying with the idea of trying to do a basic restore

[79300sdtd]

pictures
1. Air oil separator it might need to be cleaned out... i think that is posible
2. that is normal
3. Lower oil cooler line.. some leaking is not uncommon with the age.
4. something covered in oil because of the leaking oil cooler line

[compress ignite]

'parts inside air cleaner housing make up the then current Mercedes oil/air
separator (hose from the top of the valve cover supplies varying supply of
oil to the separator[then the oil drops down into the oil sump.])Look underneath
you'll see the oil return tube to the sump(there will also be an oil return line from
the Turbo that is separate.)

The oil line you picture in front of the A.C. compressor feeds oil to the oil cooler
(a radiator for the engine oil.also visible in your picture)

Oily Greasy round thing is a rubber sub-frame bushing.[I believe](It'll not like the exposure to petroleum products and will probably have a shorter life span as a result.)

[JimSmith]

As noted the assembly in the center of the air cleaner is a device that is intended to separate the oil droplets from the gasses that make up the "blow by" that is fed from that uncovered hole in the top of the valve cover in one photo to the air cleaner assembly. As the volume of blow by grows for a variety of reasons, the capacity of the cyclone separator is reached, then overcome, and it leaks some oil into the air cleaner. The capacity is somewhat reduced when it fills with oil, so cleaning it out may reduce the amount of oil that is dripped into the air intake. The same is true with the drain line - over time it can become contaminated with junk that mixes with the oil and sticks to the tube and reduces its ability to drain away the oil that is collected. Changing to a synthetic oil may also be beneficial (it flows better as it cools off). In a practical sense this is not worth getting upset about enough to do much more than cleaning out the parts and trying to keep leaks to the outside of the engine and onto the ground to a minimum.

The oil cooler line is also likely not something you want to do much about unless the leak is offensive to you - it will drip on the ground and make stains, etc. Fixing it is a significant chore and will likely involve a new cooler and set of hoses (can run over $500 in parts alone). On my car the problem became more than a housekeeping issue when the bottom of the cooler blew out due to rust. In that case there was little choice.

In general the black rubber suspension parts don't like being dunked in oil, as noted above. They soften and begin to disintegrate. A good car wash that also addresses the underside of the car will help here.

This site has loads of virtual experience to offer. So, if you want to keep it as a beater or restore it, keep asking questions. In the end, it is likely the enthusiasm from the members will have you fixing it up to be at least mechanically sound in no time. Jim

[PutPutPut]

Thank you all again very much for all the info.

The most challenging element of this is the vocabulary - it'll take some time and research to get through it all (e.g. "blow by" was a quick google search, never knew what that was until now), all of which is exhausting because of the sheer amount of info, but fun. It helps that your explanations not only include what the parts are, but what they do.. very appreciated!

Some follow up questions:

What's a "sub frame bushing" for?

While tightening the oil pan bolt after draining, I saw one more place with a fresh drop appearing on the base (actually looked like oil) - in the third picture above, there's a piece in the far right center that's cut off (it's the silver thing).. can anyone tell what that is, or should I take another photo?

The "hose" that connects the air filter tube over to the valve cover is attached to the valve cover via a squeeze clamp. This clamp is.. loose (I couldn't tighten it, but it freely rotated around the hose), I'll replace that just for laughs. However, there is no clamp on the hose->airfilter spout, the hose just sort of gets pushed over the "bulb" on the spout. That might be why there's quite some gunk on the top of the air filter housing cover? (not pictured).

I was surprised how easy the oil change was The biggest "d'oh" occured when I lifted the oil receptable by the handle (one of those that you can take to recycling center, dump, and reuse), gleefully walked across the driveway, only to look back and see the darn thing left a trail of oil - it leaked from the spout which faced down I'll be spending tomorrow scrubbing, phoeey.

[compress ignite]

Third picture,center right is the pulley of the air conditioning compressor.The
AC hoses attach to the back/rear of the Compressor via a manifold(bracket).
Are you saying the AC Manifold is dripping compressor oil?'Could easily be the
"o" rings in the manifold.You're lucky, the compressor on the SD is an R-4
General Motors type that Mercedes used in the '80s.(lots of them made).

A sub-frame bushing is a rubber isolator mounted in the sub frame
that is bolted to the unibody (or Main Frame).It provides stability
without transmitting vibration.

Jim is correct the oil separator system functions well when maintained.

If you will clean out the oil separator and the drain tube(and the cover of
the air cleaner) regularly that little system will function as intended.
It is all part of the emissions control...Early Days the gases from the
valve cover were just allowed to enter the atmosphere.Now the gases
are recycled into the intake along with the oily mist from inside the
valve cover.

In your third picture, the hose with a steel spring cover (just to the right
of the oily oil cooler line fitting)is one of your two transmission cooler
lines.There is a heat exchanger inside the Radiator for the ATF that the
line feeds.