mbz 300D.. someone ran 0-20w in it!!

[NOSPRK]

hello all. i just bought a 83 mercedes 300d. OM617.912 non turbo...

story is 2 owners ago decided if the oil would work in his honda hybrid it would work in the benz..

0-20w is what i was told. previous owner changed it to 15-40w ASAP.

oil pressure at idle is a bit low at .3-.5 bar when hot. when cold idle pressure is 1-1.1bar

any revs instantly brings the oil pressure back up and it will peg 3bar.

i want to drop the pan and check the strainer/pickup. the previous owner also changed the o-rings on the filter stem with no change.

i just bought some mobil 1 delvac 15-40 and a MANN bypass oil filter.

 

[CATERHAM]

Welcome to BITOG.

15W-40 is really a mineral oil grade.
A more appropriate oil would be Mobil 1 ESP 5W-30.

 

[getnpsi]

Lets be optimistic and say the 0-20 just gave it a good cleaning, and on the drop you finish the job. Do those engines with many trips around the globe as far as mileage always post to factory spec still? To read/hear these stories is horrible. Just because the MB diesels or a gas toyota 20/22r are "bulletproof" does not mean shoot at it!

 

[oggb]

Originally Posted By: CATERHAM
Welcome to BITOG.

15W-40 is really a mineral oil grade.
A more appropriate oil would be Mobil 1 ESP 5W-30.


I don't see where he asked if 15w-40 was mineral or synthetic. It's a 1983 300D. Why would he want something like ESP 5w-30 in that?

Originally Posted By: NOSPRK

oil pressure at idle is a bit low at .3-.5 bar when hot. when cold idle pressure is 1-1.1bar


Are you certain the gauge/sending unit is correct? It'd suck to go chasing this problem only to find the gauge isn't reading correctly.

 

[Dieseldoctor]

most run right around 1 bar at idle cold dropping some when hot..and anything above 2000 rpm should peg the needle. Is the engine making any unusual noises or using oil more than 1qt/1000 miles?

 

[Quattro Pete]

Originally Posted By: NOSPRK
hello all. i just bought a 83 mercedes 300d. OM617.912 non turbo...

Is it not the original engine in this car?

AFAIK, the OM617.912 non turbo was only being used up until 1981 in North America. After that it was the OM617.952 turbo.

I know you did not ask the question, but Mobil recommends you run M1 0w-40 in it.

 

[NOSPRK]

no i am not 100% on the gauge. in my long ownership of these cars i have only had 1 oil pressure gauge fail and it still worked.. just leaked out of the oil line.

i will put a mechanical gauge on it to check pressure.


also, i dont see how 0-20w would clean it. as diesel oil has higher levels of detergent then oil for a petrol engine.

there are no knocks or noises coming from the engine. it runs great!

i cannot purchase a oil pan gasket today so tomorrow i will change the oil and report the results.

 

[NOSPRK]

Originally Posted By: Quattro Pete
Originally Posted By: NOSPRK
hello all. i just bought a 83 mercedes 300d. OM617.912 non turbo...

Is it not the original engine in this car?

AFAIK, the OM617.912 non turbo was only being used up until 1981 in North America. After that it was the OM617.952 turbo.

I know you did not ask the question, but Mobil recommends you run M1 0w-40 in it.

yes it is the .912 non turbo... this is a euro spec 4-speed 300D

 

[mongo161]

IMO...The Mobil Delvac, 15w-40 was an excellent choice for a great oil in the MB non Turbo.

If you have an AZ near you that carries German Castrol 0w-30...and you want to run synthetic....it's on sale right now.

 

[antiqueshell]

In non turbo 123 MB 10-40w or 15w40 Mobil Delvac or Shell Rotella T5.

YOU DO NOT want to use too thin an oil in this engine. In most of the USA 10w40 is a great choice.

 

[NOSPRK]

Originally Posted By: antiqueshell
In non turbo 123 MB 10-40w or 15w40 Mobil Delvac or Shell Rotella T5.

YOU DO NOT want to use too thin an oil in this engine. In most of the USA 10w40 is a great choice.


i feel a 5w (for cold) is minimum. but im just a young home mechanic.

im just hoping there isnt any major damage done from the ignorant prior owner. the person i purchased it from changed the oil ASAP but he also put low miles on the car. he did drive it to work atleast once because i first looked at it there. i feel if the oil pressure was inadequate it would of siezed up a long time ago. i open the oil cap while running and i see oil on the cam/rockers. the cam shaft looks amazing. no wear from the first 2 lobes i could see

im hoping for a easy fix but im expecting a long block swap.

 

[sunfire]

I would just get over it. What's done is done. Reckless drivers are far more dangerous to the engine than 0W-20 oil.

 

[fdcg27]

Don't trouble trouble until trouble troubles you.
As long as the OP gauge is pegged in normal off-idle operation, and as long the needle is indicating oil pressure at idle, even when warm, I'd say the engine is probably okay.
I would not use 0W-20 in one of these things, and I've owned a couple of 240Ds, basically the same engine with one less cylinder.
Still, these engines have ridiculously low specific output, and they aren't exactly rev-happy either.
If the thing runs well, and the experiment was done two owners ago, I'd say that the engine probably survived the event.

 

[morris]

why do you cats pass water off as oil?

 

[CATERHAM]

Originally Posted By: JRed
Originally Posted By: CATERHAM
Welcome to BITOG.

15W-40 is really a mineral oil grade.
A more appropriate oil would be Mobil 1 ESP 5W-30.

I don't see where he asked if 15w-40 was mineral or synthetic. It's a 1983 300D. Why would he want something like ESP 5w-30 in that?
Originally Posted By: NOSPRK

The OP said he bought Mobil 1 Delvac 15W-40 but the synthetic M1 isn't made in 15W-40 grade, which as I mentioned is a dino grade.

M1 ESP 5W-30 is an excellent deisel oil and a vastly better choice over the archaic 15W-40 dino.
But as Quattro_Pete pointed out, If M1 0W-40 is spec'd for this engine it's even a better choice due to it's high VI.

 

[eljefino]

Why would the middle owner even mention the previous owner's shenanigans? I guess he likes to chat about these cars.

My 240d indicted 2.1 bar or so at hot low idle and pegged at 3 the rest of the time on 15w40.

 

[NOSPRK]

Originally Posted By: eljefino
Why would the middle owner even mention the previous owner's shenanigans? I guess he likes to chat about these cars.


the guy was being honest. i got it at a good price because of the low oil pressure. he was not trying to scam someone.


it doesnt peg 3bar all the time. it always rises and stays in the 1.5-2.5 bar mark around town. on the highway at speed its not pegged but close.

 

[Dieseldoctor]

imo 5w weight oils are a must for starting the old engines as most arent in great shape and the glow plug system if you dont have the updated afterglow they're nearly impossible to crank under 20 degrees out. in summer i'd go with 15w40. Having said that i'd figure out if your gauge is reading correct.

They're is someone on here who runs 20w oil in alot more exotic engines i dont see it hurting anything honestly unless the oil pressures actually low then i think u have oil clearance problems ie prolly wore out bearings. I think also the oil squirters dont open till they get to 1.5 bar i cant remember.

 

[Trav]

In your climate 15w40 is fine, don't even consider 0w20 in this engine.
Quote:
oil pressure at idle is a bit low at .3-.5 bar when hot. when cold idle pressure is 1-1.1bar

any revs instantly brings the oil pressure back up and it will peg 3bar.


That's about 6-8 psi. It will survive on that at idle.

 

[Rollins]

The pressure relief valve on the oil pump might have become loose. The service manual suggests using a "sealing compound"on the threads.Check it while you're there.