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

[NateDN10]

Originally Posted By: 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.

I'm with this guy. If it's not burning oil excessively, doesn't make odd noises and runs fine, why worry? Maybe do a few UOAs to be sure.

 

[The_Eric]

Originally Posted By: NateDN10
Originally Posted By: 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.

I'm with this guy. If it's not burning oil excessively, doesn't make odd noises and runs fine, why worry? Maybe do a few UOAs to be sure.


X's 3

 

[mechtech2]

I'd stick with dino 15-40 and see how things go.
It may be another 100k before you see a change, though!

 

[NOSPRK]

i have not changed the oil yet. i dont think it will make much difference as the previous owner has already changed it. i will check everything out when i drop the pan

 

[JHZR2]

Welcome. I have owned multiple w123 cars and love them. I currently own two. I run 5w-40 in all of them. 15w-40 is fine too. You want an HDEO for soot dispersion.

At cold idle on a good engine, your oil gauge should be pegged. As the engine warms it should drop down to about 1.5 bar, and immediately peg back to 3 with any slight throttle.

Your pressures are very low, possibly in spec, but way lower than any w123 that I have owned.

FYI, an 83 should be a 617.952, as 83 cars have turbos. Oil and pressure doesnt matter, the pressure characteristics are identical on every 617.952 I have owned, which are identical to my 240D with 616 engine.

Obviously 0w-20 should not be used in the engine, unless the temperatures are very low.

Viscosity charts, per the FSM and MB, are as follows:

Old:

Updated:

Glad you replaced the two small o rings on the filter shaft - they effect the bypass operation. They should not effect your pressure though.

 

[JHZR2]

Originally Posted By: CATERHAM


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


Not for a w123.

 

[NOSPRK]

thanks for your post and your charts. for the price and the miles i put on cars/trucks i run 15w-40 in all my old diesels. i have a 91 dodge cummins with 400k on the original engine. i bought the truck from the original owner. delo 15-40 its whole life. only big issue was one headgasket replacement at 300k hone marks still visible.

yes i know 0-20w is not correct for these cars.

this car is a euro spec 1983 300D N/A .912 with a 4speed manual.

i dropped the pan today. only thing i found in oil strainer was some old RTV from a oil pan gasket. no metal. everything looked okay.

pressure regulator was not loose. new lower pan will be in tomorrow morning. i did replace the oil filter housing o-rings on the stem with no pressure change.

i might swap a oil pump if i can find one

 

[45ACP]

I have read this thread.

Choose GC IMHO.

 

[NOSPRK]

ok guys. i think i found the problem. stuck/broken oil pressure relief valve. it feels like its broken. it will pop and give after pushing on it. you have the tap it on a solid surface to get the plunger to return

 

[45ACP]

Did you decide on an oil?

 

[NOSPRK]

i bought those before making my first post. i dont see a issue

im having a issue finding a relief valve. is it even possible to get one new?

 

[Rollins]

Yes, they offer a repracement part :

A616 180 01 15- UP TO ENGINE:
912 10/50,20/60 -...153779
912 12/52,22/62 -...140007


------------
A617 180 00 15 :

FROM ENGINE
912 10/50,20/60 ...153780-
912 12/52,22/62 ...140008-





...
MB also offer the piston(A321 181 00 42) and the pressure spring(A616 993 02 01) in case the valve body is OK.(cheaper option it seems).

Swag and Febi also offer their replacement parts
A616 180 01 15 = Swag 10 90 7115 =Febi 07115

----------
A A617 180 00 15 = Swag 10908412 = Febi 08412

------------
The quoted pressure relef valves were also used on om616.912 engines.Should be easy to find used.I think you'll have a happy engine soon.

 

[NOSPRK]

UPDATE!!! I spaced out after i fixed the problem..

so it was the oil pressure relief valve. it was stuck in a compression. i could slam it on a table and the spring would pop back..

MBZ dealer laughed at me. found one NOS from a old parts guy in so-cal. $50 and 2 days later problem fixed!!!!

been running high miles since i fixed her. no issues.


thanks for all your help. i am new but i hope to hang around here

 

[JHZR2]

We need a picture of the car now!!!!

 

[Merkava_4]

Whenever I see one of those old Mercedes diesels on the road, I usually take drastic measures
to get away from it. I try to avoid choking on that black sooty smoke if at all possible.

 

[Jarlaxle]

And NEVER get stuck behind one on a hill!