i use 15w40 weight oil,for the best diesel oil use Cummins brand

__________________
1999 w140, quit voting to old, and to old to fight, a god damned veteran

Same here, on oil, I do change filters more often tho.

__________________
83 SD

84 CD

I use Delo 400LE 15W40. I change the oil and filter about every 3000-4000 miles. I add any if it is needed between changes but usually I am a little above the fill mark when I do a change.

__________________
1991 F250 super-cab 7.3 IDI. (rebuilt by me) Banks Sidewinder turbo, hydroboost brakes, new IP and injectors.
2003 S430 - 107K
1983 300SD - Tanoshii - mostly restored ~400K+.
1983 300SD - Good interior. Engine finally tamed ~250K.
Monark Nozzle Install Video - http://tinyurl.com/ptd2tge

Ditto here; Valvoline Premium Blue is what I use. When it first came out in the late 80's it was known as Cummins Premium Blue.....good stuff for dino oil.

__________________
1985 300TDT
2013 E350 Bluetec

I have change over my oil from Moblie 1 delvac to Liqui molly SAE 15W40 touring high tech. Was this a smart move or did I just screw up ???

__________________
Revenge is a meal best served cold

1980 300SD, Shotzie
1996 Volvo 850, Dark Night
1997 Ford F350 7.3, The Tuna Clipper

The only screw up you made is by asking an oil question.

In all honesty, you're fine.

I always ran Rotella T 15w40 in the summer time for my 300D because it was cheap and I could get it in bulk.

In the winter, I switched to Rotella 5w40. Again because it was cheap and I could get it in bulk. The 5w40 in the winter was to help with cold starting and it did the job admirably, starting in sub zero central New York weather.

I changed religiously at the 5k miles mark.
The car ran great. No issues and burned very little oil.

Really, this is more of a testament to the PO who took great care of it. The oil just lubed an otherwise good engine.

The advice to change the oil every 3K miles on dino for these engines is absurd and expensive. These cars take like what, 2.1 gallons?

If you really want a definitive answer, send a sample of oil to the friendly fellows at blackstone-labs.com

They gave me the ok to EXTEND my Dino Rotella 15w40 oil changes to 7k miles without issue.

When it comes to oil for cars that need 2+ gallons of it, give me bulk and let me run it for 5k.

For my 380sl, I run Mobil 1 15w40 in it because that's what cheapest at Sam's Club. No sense paying more for special stuff.

In short: you're fine. Drive and enjoy.

__________________
-Typos courtesy of my mobile phone.

I would only run 15w-40 if weather allowed, my brother and I run 5W-40 in the diesels and 0W-40 is the gasser.

My brother also runs Liqui Moly M0S2 in the crankcase, Liqui Moly 75w-90 synthetic in the diff along with their M0S2 formulized for gear oil as well. For all of our cars.

I b**ch at my brother and make him change transmission fluid, gear oil every, power steering fluid, every 30k. So far the E320 and E300 still runs GREAT.

Also I change brake fluid once a year, i know it's overboard but it makes me warm and fuzzy.

__________________
1998 Ford Escort ZX2 5 speed - 279,000 miles My Daily

1992 Mercedes 300D 2.5 202,000 - Pure junk
2000 Mercedes E320 Black - 136,000 miles - Needs repair

Don't forget to grease the screw and threads on the spring compressor.

This. 5K on any of the name brand 5w40's is safe. No need to fear a few short runs, either - take it out on the town for an errand or ice cream periodically. It won't bother the engine as long as that's not all it's used for.

__________________
'82 300CD
"Pearl", the very first turbo diesel 123 coupe
Totaled 11/23/18, rebuild in progress.
'85 300TD, "Artemis".
'78 300D euro, "Ol' Red", mostly retired.
'85 300D, "Gandalf".

Do gasoline engines suffer from fuel dilution more or do non gear heads akathe general public idle a lot?
I ask this because more often than not when I changed motor oil it reeks of gasoline, however my E320's dipstick does not have this smell.


I don't idle over 1 min unless at drive through.

__________________
1998 Ford Escort ZX2 5 speed - 279,000 miles My Daily

1992 Mercedes 300D 2.5 202,000 - Pure junk
2000 Mercedes E320 Black - 136,000 miles - Needs repair

Don't forget to grease the screw and threads on the spring compressor.

Run a name brand oil that meets the engine manufacturer's spec, is within the manufacturer's specified viscosity for the temps you'll encounter, and change it and the filter at the specified time.

I run whatever 5w-40 diesel oil is cheapest when I buy oil.

Within those bounds, your oil choice will not be the limiting factor on your engine's lifespan.

__________________
617 swapped Toyota Pickup, 22-24 MPG, 50k miles on swap

Seriously ,

Any modern motor oil that's C (Diesel) rated is going to be orders of magnitude better than the Dino based crap they were designed to use, will be fine .

Just change it reasonably frequently and always hot and the filter too and you'll be fine .

Oil is like politics ~ all reason and facts go out the window for some odd reason .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

M1 0w 40. Approved by MB for all diesels without particulate filters....pre-2007. Easy to get at Walmart and cheap.

7.5k interval/ 1 year (whichever comes first) with normal driving....W115, W116, W123 and W124 with diesel engines. W211 OM648 vehicles can use this with 12k intervals (1 year). Again under normal driving conditions. More frequent changes...you are just doing unnecessary work and wasting resources.

0 weight for starting is great in very cold climates. 40 weight is ideal for all but hottest climates (seldom seen consistently in US).

__________________
-- Chris

'95 E300, 216k miles, Silver Surfer
'05 E320 CDI, 138k miles
'07 S550 4matic, 69k miles

Gone but not forgotten:

'76 300D, 350k miles?, SOLD in 1995
'75 240D, 300k miles, SOLD in 1991

X2 on the Valv Prem Blue. The napa fleet 15-40 is speculated to be the same, but cheaper, and goes on sale more. Always seems like the oil loss over time is less when I use that oil. Tractor Supply has a 15-40 fleet oil that is also well made for the price.


Get a metric o-ring set (autozone?) that has the little o-rings that go in the filter housing and change em out too - there is a forum thread on that.


My personal method is to unplug the glow plug relay so I can crank the engine over for several seconds to build some oil pressure before the first start after an oil change.

__________________
1985 300TD 1981 Scirocco 1.6D conv 1986 Golf 1.6D 2003 Golf TDI

One is 6MM, the other is 7MM .

Make sure they're Diesel fuel resistant, regular O-Rings are not .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Bear with me for a moment - not necessarily a simple answer.

From my understanding and research the OM61x engines' oil change interval is dictated primarily by soot loading. The nature of their IDI design means they're less efficient than a DI diesel (like a VW TDI, Cummins 6BT, or modern Duramax, Powerstroke, etc.) and that begats more combustion contaminants in the oil. When soot saturation reaches a certain level it will result in accelerated wear, BUT that point on a 617 in any decent state of tune is far past what's seen under normal 3-5,000 mile intervals. My concensus when I got my 300CD and wanted to insure the engine's longevity was that 5,000 miles on a synthetic oil was safe under any conditions and regardless of how poorly (aka, inefficient) the engine could be running. Synthetics withstand heat better, are "slicker" (lower friction) and they also capture and control afore-mentioned soot better than conventionals. Not to mention the 617 holds two gallons of it, which is a much higher oil-volume-to-displacement ratio than a lot of engines of its day that still have a reputation for great longevity.

I've not done a lot of comparing of diesel vs. gas fuel dilution levels, but I *think* your average gas engine will have less fuel or fuel by-products in the oil than your average diesel. However! This doesn't apply to direct-injection gas engines, which started getting popular about 10 years ago and now are basically the norm. Instead of injecting the fuel into the intake manifold or head port, to be sucked in when the intake valve opens, they moved the injector into the combustion chamber - like a diesel engine. This allows higher compression ratios, where gas present in the combustion chamber on the compression stroke would pre-ignite, but when sprayed at the point ignition is needed followed by the firing of a spark plug it burns normally. Basically borrowing diesel designs to make gassers more efficient. Anyway, DI gas engines commonly dilute the oil worse than port-injected engines, sometimes to a point that can compromise the oil's ability to lubricate not far outside the recommended change interval. DI has had plenty of teething problems - troublesome injectors, high pressure fuel pumps (HPFP), carbon buildup on intake valves (because there's no gas passing by the intake valves to keep gunk washed off), etc.

That's not the whole scoop, but maybe it'll give you a better idea of the whole fuel dilution thing. BobistheOilGuy forum will have days worth of reading on this, if you care to search.

__________________
'82 300CD
"Pearl", the very first turbo diesel 123 coupe
Totaled 11/23/18, rebuild in progress.
'85 300TD, "Artemis".
'78 300D euro, "Ol' Red", mostly retired.
'85 300D, "Gandalf".