Somewhere in the archives there is a thread where people went out and measured their dipsticks... on their MB engines... for exactly this comparison...
A lot of people say anything above the half way between full and low will cause a lot more oil burning... I know that is the case with my car....

I would go for the stick NA 300 engine if it were me..
SO much more room in the engine compartment....

__________________
1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/diesel-discussion/10414-help-i-need-check-stretch.html

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

Or sell it to me... what does it need, if I might ask?

__________________


Mac
2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

“Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22

1980, Manila Yellow with Tobacco interior, no sunroof, about 500,000 on odometer. Guy I bought it from was a smoker and the interior is fair at best. Body is straight and I didn't find any significant rust, basically just minor dings and scratches. Needs front and rear window seals which I have new and uninstalled. I bought it several years ago from the PO in Largo, FL, then drove it home and haven't done much with it since. The tranny seemed to late shift, maybe flare, so I figured to go through it and do a good tuning but just never got around to it. I've got Euro auto-leveling headlights for it and I think the switches too, which would go with the car. If interested let me know and I'll send some pics.

__________________
Joe Black
Get yellow fever at ACME!

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

I'll take another look at the tailpipe tomorrow and report back. What you suggest isn't unreasonable, I'm just frustrated and tired of pulling wrenches on this car. But I also can't stand not knowing and am pretty anal about stuff, which is why I got into aviation maintenance. Question: would oil puke out of the glow plug hole just as likely as it would the injector port? If so I didn't get any oil spray when doing compression checks which I did through the glow plug holes.

The only thing I probably haven't explored is something I've seen mentioned here about oil getting into the IP through an o-ring IIRC. I'd think a side effect of that issue would be improved fuel economy, lol.

__________________
Joe Black
Get yellow fever at ACME!

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

Engine oil Dipstick length thread



.

__________________
ASE Master Mechanic
https://whunter.carrd.co/

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
2003 Volvo V70

https://www.boldegoist.com/

LOL, Do you ever sleep Roy ? Thanks.

__________________
1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

It was a bit of a long shot anyways since you quoted the oil additive reduced oil consumption. Yes you would have noticed one glow plug hole spitting oil out during your compression check.

The o ring you are thinking about I believe is in the lift pump. The fuel is under greater pressure so it thins the base oil. At about 500k indicated if it is the original unrebuilt or original engine. That compression reading was pretty good. Plus at that milage the oil rings could wear out and the compression rings hold up better somehow I suppose. .

OM616 Lift pump Repair kit W123.123



FYI:
When the diesel lift pump leaks fuel into the crankcase, it is called making oil = one of the causes of a runaway engine.

Run away diesel, why does it happen?
Run away diesel, why does it happen? - PeachParts Mercedes ShopForum





Fuel injection pump starvation with a good lift pump
Fuel injection pump starvation with a good lift pump - PeachParts Mercedes ShopForum

Fuel pressure relief valve adjustment
Fuel pressure relief valve adjustment - PeachParts Mercedes ShopForum

lift pump test
1979 300td -- Can anybody walk me through a lift pump test? - PeachParts Mercedes ShopForum

fuel pressure
fuel pressure - PeachParts Mercedes ShopForum

Did you try, after a long drive, pull the glow plugs (do not glow them again) and see if they are all dry or wet or different from each other? If it was run on WVO single tank chances are the rings are coked up and not "springy" anymore thus the high oil usage.

__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Man you be brave: 500k? Original head/engine?

Climate control functional?

Thanks

__________________


Mac
2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

“Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22

Roy, is this where others have said oil could be getting into the fuel? Where the pump is driven?


Funola and Barry123400: I still plan on doing a follow-up compression check since I got the valves readjusted so will take a piece of white cardboard and spin the engine with the glow plugs out before I hook up the tester. I'll also note the appearance of the plugs after pulling them after engine shutdown. Between that and whatever gets sprayed on the cardboard should at least answer this line of thought. Oh the suspense! LOL!

Zacharias: I usually don't shy from higher mileage vehicles and tend to assess condition on a number of metrics based on personal experience over the years. My first car was a '71 Ford Fairlane my Dad bought me for $25 and after driving it up and down the street for a few weeks I sold it for $380, so that may clue you into the class of vehicles I've been dealing with mostly. My W116 runs strong but smokes a bit, didn't seem to use any measurable oil on the 70 mile drive home, and the climate control worked but there's a leak in the AC system that at the time would hold a charge for just a few days.

__________________
Joe Black
Get yellow fever at ACME!

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

Yes, that is the potential leak point.

Okay, call me stubborn, but I just can't let this go even though my 240 is likely going to be on eBay very soon. So my question is this: How much oil could possibly be drawn through a faulty lift pump into the fuel supply? And is there a simple way to check? At first I thougt about just dumping the spin-on filter into a jar to see if there's oil in the fuel there, but then I thought I should see it in the primary filter from oil-laden fuel being returned to the tank.

Today I started being a bit more attentive to the actual oil amount I'm losing. On a 100 mile drive, 70 of which was interstate at 65 - 70mph and the rest city/highway mixed at 40 - 60mph, I used about 2 1/2 quarts. I started with the oil midway between the notches on my dipstick (red handle) and after the 100 miles it took just a bit shy of 2 1/2 quarts to get it back there. Now that's with some of that Lucas Oil Stabilizer in there, maybe almost 50%, and the last of it too as I finished off the gallon topping off prior to the drive. Glad that's over with! What should I try next? Rislone or just go straight to the 85W140 gear oil?

So the last two fill-ups I'm getting a solid 28MPG, meaning that in that 100 mile drive almost 4 gallons of fuel was consumed along with 2 1/2 quarts of oil. Is it feasible for the lift pump to get that much oil into the fuel? Maybe this is combinational, some through the rings, some valve stem seals, some lift pump and some breather. It all adds up to a pain in my tuckus! I finally gave in and bought 3 gallons of SuperTech Universal 15W40 just to get me through the week! Rotella and Delvac are like caviar at this point compared to $10 a gallon Walmart oil, lol.

I just can't stand not knowing what the cause of this issue is. Wednesday or Friday I plan to revisit compression and try checking for oil spray and residue as suggested by Funola and Barry123400, we'll see what the next chapter brings then!

__________________
Joe Black
Get yellow fever at ACME!

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

You have the possible issue reversed..

Diesel fuel is entering the engine crankcase = thinning the lubricating oil.

As the oil gets thinner, normal mechanical motion causes it aerosolize on a MASSIVE scale.

This is a very thin HOT aerosol spray of engine oil/diesel fuel.

If the valve guides and/or piston rings have leakage = unregulated fuel entering the combustion chamber.

If the turbo seals are marginal = the thinning lubricating oil can become a serious leak = unregulated fuel entering the combustion chamber.

The crankcase vent tube can pass a huge volume of this thin HOT aerosol spray directly to the intake = unregulated fuel entering the combustion chamber.

My oil doesn't seem thin as it would diluted with diesel, plus I ran the car like this for a while: and it still used the same amount of oil so it wasn't going into the intake. I'm going to guess you didn't catch this is for an OM616 as far as the turbo seals go.

I'll dig around and see if I can find that thread that mentioned oil getting into fuel via the IP or lift pump...

__________________
Joe Black
Get yellow fever at ACME!

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