I'm sure this will bore everybody to death,but I for one have enjoyed going into the archives looking at other oil-related articles-so here's mine!
I purchased my 1982 240d on Feb.8,2004.I did my first oil change on Feb. 11 at 237,251 miles.I used a filter purchased at the dealer along with Mobil 10-30 5000 Extended Life oil(it was the only "C" rated dino-oil I could find in 10-30 weight).According to the maintenance records that came with the car(I appear to be the 4th owner)the oil was last changed Mar.1,2001 at 228,100 miles.I'm not sure if this is correct because this entry was in the last available spot in the Maintenance Booklet,but it is a possibility.The owner before me owned the car 2 years and drove it less than 4k miles.When I did this first change,it was before I found this site,so as hard as it is to believe that a guy can't do an oil change right-well,that was me.The weather was very cold,and the old oil dripped forever-so,being used to Chevys and Buicks,I put the drain plug back in and filled it up.It took only 5 quarts which I thought was strange as capacity is 7-but like I said this was a whole new experience to me.The thing that really got me was that when I checked the level before even starting the car-it was PITCH BLACK!It was as if I never even changed it!I then found this site,and read about the 2 small oil rings on the cap stem.I drove it 1100 miles and changed the oil and filter again on 3-11-05.I found that the o-rings needed replaced-I originally thought the bottom one was a steel ring!I couldn't get the new o-rings in time,so I went ahead without replacing them-but this time I let it drain all day and it took 5.5 quarts to fill.Again-oil was very black before even starting the car.I then drove it 1200 miles and changed oil/filter again yesterday.Came out pitch black-let it drain all day-replaced the o-rings-filled it to check the level-and it was CLEAN!!!!I was very happy!It took a full 6 quarts to fill.Checked the level after I got to work this morning-and it was still relatively clean!So now I will be on a regular 3k change schedule.

Von,

Oil looking clean is not a test of how the clean the oil is in the engine. Oil in a Diesel engine will look black because of the soot in the oil from burning Diesel fuel. There is a pypass oil filter in conjunction with the full flow filter to filter out the soot, but some stays in the oil but within limits, it does not harm the engine'

The only way to tell if the oil is contaminated is to do an oil anaylsis. If you keep changing oil to keep it looking clean, you will be doing an excessive amount of oil changes.

P E H

this is your first diesel???
diesel oil is normally black after a few miles running.
just change it every 3 or 5 thousand.
use good quality filters like Mann or Bosh.. not Puralator or Fram.
my 5 centavos.
r

__________________
Current money-pits:
96 Passat TDI
78 300D 100k miles(60miles/day)FOR SALE
91 Jetta Diesel 250k miles (80miles/day)
82 Toyota Diesel pickup 150k miles; out of service for a little while with a valve problem.
All on BelenBioDiesel
Past diesels:
01 Golf TDI
81 Isuzu P/U
85 Jetta
89 KW 425 cat
85 Pete 400 cat (currently still running the west coast with over 1.5 million miles)
81 KW 400 Cummins
77 Freightliner CO ???? Cummins (Buttercup)
57 180D lots of miles(gone but not forgotten)

according to the owners manual in my wifes car the 240 takes 6.9 quarts . no wonder folks buy oil by the gallon. that was my whole shelf of m1t&s.

old navy has a nifty device on the oil pan that makes oil changes easy it is brass with a tab you move to let the oil out. no messy oil draining on your hand before it hits the pan.

find it here

http://www.fumotovalve.com/

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currently
[1981 300 td tdidi 165500 dark brown/palamino-Brownie-mine-3k miles of ownership
1983 240d 162+++ Anthricite grey w/ henna red interior and hella lights-wifes car-Red

the above two cars are for sale
and can be seen on the cars for sale thread here. pix also available.


240d-144+ Manilla Yellow w/ palmino interior-greasecar kit-Blondie-the college kids car

23" gt 21 speed still on original tires-still got the nubs
21" khs tandem

Oil always looks dirty in our motors since there is normally a good quart or so in the oil cooler that isn't getting changed. The day I check my oil and it looks clean I'd worry, good diesel motor oil carries the soot to help save wear on the motor.

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Jeff M.
Mercedes W123 DIY pages are now located here.
1983 / 1984 300D Sold
2000 CLK430 Cabriolet ~58k Sold
2005 Avalanche 4x4 ~66k

I have an 82 240D which I've owned two years. I change the oil often and it also annoys me that it gets dirty so soon. I'm not aware of two "O" rings that should be replaced, just the one large one at the oil filter. My 240D has 287,000 miles on it but the engine was rebuilt 40,000 miles ago. It runs great and starts very fast without smoking or missing, but it uses plenty of oil, a quart every 800 miles at best. Where are those two "O" rings?

"I originally thought the bottom one was a steel ring!"
Me Too, I was sure it was metal until I put an exacto knife to it... and it Shattered.

The rings in question are on the tube which goes down in the center of the oil filter... and is attached to the oil filter case cap....

When you unbolt the canister's top and take the thing out... you know how there is a long stem? Well on that stem there are two black orings, generally harder than a rock since most people have the same answer you did. I know I had to break mine off. Anyway if you don't replace these from time to time the oil may bypass the oil filter, which is not good!

__________________
Jeff M.
Mercedes W123 DIY pages are now located here.
1983 / 1984 300D Sold
2000 CLK430 Cabriolet ~58k Sold
2005 Avalanche 4x4 ~66k

Yes-this is my first diesel-and I'm in love!This is also my first foreign car.And-yes, I know that clean oil doesn't mean it's good oil-I just found it interesting that it got black so quick!As far as the location of the 2 small o-rings-they are on the bottom of the stem on the oil filter cap/lid.As a side note-I also blew out the holes in the stem with air and brake cleaner-a lot of crud came out!

"blew out the holes in the stem with air "
That is often forgotten when people talk about the those o-rings... but is very important...

All mine did is spray oil out and make a mess.

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Jeff M.
Mercedes W123 DIY pages are now located here.
1983 / 1984 300D Sold
2000 CLK430 Cabriolet ~58k Sold
2005 Avalanche 4x4 ~66k

Where do you get those little "O" rings?

My car never did have them and I see the two grooves in the shaft.

Thanks

YIKES!! Get some in there NOW!

Without them, you're starving your engine (not quite but almost) of oil everytime you start after sitting a while.

You can take the stand to a HW store and match some to fit, or order from Fastlane, Rusty, etc.

If you don't have another car, drive it to the HW store, pop the hood, unbolt the 2 13mm nuts on top, pull it out, rag it and take it in. Show someone the grooves and tell them you need O-rings to fit both (same size.)

The factory ones are the same material, Buna-N. If you want some that will last, get them in Viton (holds up to thermal cycling better.)

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1984 300D Turbo - 4-speed manual conversion, mid-level resto

1983 300D - parts car

1979 300TD Auto - Parts car.

1985 300D Auto - Wrecked/Parts.


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"If you don't know where you are going, any road will get you there". Lewis Carrol

The o-rings are 6x10x2mm. They should be available at the typical auto parts store. Finding metric o-rings at a hardware store is often a challenge.

I wonder if it would be worthwhile for someone to buy Viton O-rings of the right size to sell to Shopforum members? This isn't a "get rich" scheme, as anyone can buy OE rings from Mercedes at a minimal price. These have to be one of the cheapest items in the entire car, but of fairly high importance. If you want to keep oil pressure in the proper range and have an assurance that oil will flow through the filter as it is supposed to then these 2 little rubber rings are critical.

For someone who wants "the best" O-rings made from Viton would be ideal and it probably won't cost much more than regular ones.

FYI. I just spoke with an associate that used to buy O-rings from Apple Rubber Products in Lancaster, NY. He doesn't know what their minimum order is. Their tel# is 1-800-828-7745 in case anyone wants to run call them for a quote. I am willing to buy a dozen myself.
The only two measurements necessary are the ID and the wall thickness. The OD is a result of the other two dimensions. So a 6.0 mm X 2.0 mm might be right. Can someone mike one and see.

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'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!