LOL, yup just the ol' 2.4L four-banger chattering away underhood. And this has only 215K miles on it, my W116 is the 500K+ miler.

We'll do new compression check this weekend and will see if any oil sprays from the open glow plug ports. If I have my tool back in time we'll also do differential compression as well.

I plan to stop by a few NAPA locations locally over the next two days to see if they've got or can get an inexpensive 50W or 20W50 diesel-rated oil for me to try. While at Walmart today getting more of their SuperTech 15W40 Universal I was really considering using the 80W90 gear oil!

__________________
Joe Black
Get yellow fever at ACME!

Just the MB's: '82 300DT (stick), '81 240D, '80 300SD, '80 300D, '81 240D Manual

I think 20-50 multigrade is too simular to 15-40 and may just result in more confusion. You really want straight 40 or 50. Since you already stuffed a viscosity additive in with no effect is not certain enough. I have heard that this brand can be found sitting at the bottom of the oil pan sometimes.

At 215K and you believe the odometer is right. Unless something really odd has happened with this engine usually they are still very good.

I now understand the compression numbers you are getting. A possible head gasket failure is now moving upward. The 40 or 50 oil will tell the story.

I never used oil as a test but on the few cars that consumed oil excessivly in my possession switching to straight 40 from 15-30 multigrade halved the oil consumption or a little better. These were cars with known cylinder issues.

Another thing I neglected to ask. You are an experienced mercedes diesel owner. What does the blowby look like from this engine. Excessive or within the normal range. How does it handle the loose oil cap test?

when you do the compression test and the readings are low
put a little oil in the cylinder (tablespoon maybe) and see if you get a significant increase in the reading . If so then you have a ring problem. Your rings could be stuck from WVO usage.
My gut says your rings may be ok as you are not complaining of a bad startup when cold.

You are ingesting the oil from somewhere and a failed vacuum pump would be my first choice.

I'd be careful about putting a tablespoon of oil in your combustion chamber. A teaspoon is more like it. I have calculated the volumn of the combustion chamber before and it is like 1.5 CI. If you get that or more in it you may bend a rod with hydrolock.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

You are right..
We usually give several shots of oil from an oil can.
I don't cook so I am not familiar with excactly how much a tablespoon holds but I know a teaspoon is smaller and would be better.

The volume equates to .03 L which is almost exactly 1 oz.

Therefore, two tablespoons would be the limit.

Piston-type, single line. Eliminated earlier.

Got my differential compression tester back today and also picked up some Rotella 40W from local NAPA, they couldn't get any 50W diesel-rated oil. Hopefully tomorrow or Monday I can get the new compression numbers.

I'm definitely selling the car in the next couple weeks. I'm either going to put a 300D on the road or my M1028 CUCV, I just don't have time or $$$ to rebuild or replace this engine. Hopefully all this information will prove useful to the next owner as I'm a full-disclosure kinda guy and the rest of the car is pretty nice, especially since I welded in new steel in the floor!

__________________
Joe Black
Get yellow fever at ACME!

Just the MB's: '82 300DT (stick), '81 240D, '80 300SD, '80 300D, '81 240D Manual