Mercedes om 321!!!!

[jenevers]

a friend of mine has a 1965ish Merc OM 321 in his boat and can't find the correct engine oil spec for it anywhere. Apparently it has a stainless steel mesh oil filter so sounds a bit like the old Gardner system. Anyone got any ideas as to whether he should be using SAE 30 API cc or similar. I KNOW it's not a Gardner but thought the knowledge might be out there with someone.

I've looked in the "Others" section but there's no mention of Mercs.

Edited May 12, 2015 by jenevers

[PeterG]

To be honest your logic sounds good on the grade and type of oil with the design and filter style if that is original. However my knowledge of this engine is very limited so I would and could not formally recommend it.

 

I am presuming that this is a new engine for your friend and there is no one else to ask?

[PeterG]

Worth trying here for an answer.

 

http://www.benzworld.org/forums/benzworld-help/1208462-mercedes-diesel-engine-om-321-a.html

 

Peter

[jenevers]

Worth trying here for an answer.

 

http://www.benzworld.org/forums/benzworld-help/1208462-mercedes-diesel-engine-om-321-a.html

 

Peter[/quote

 

Thanks but no info re correct oil.

[Alan Saunders]

The major oil companies, e.g. Castrol, have technical departments that can be contacted by 'phone or email for advice on the correct oil to use.

[jenevers]

The major oil companies, e.g. Castrol, have technical departments that can be contacted by 'phone or email for advice on the correct oil to use.

 

Thanks, I've emailed Castrol.

[martyn 1]

I have a manual foe the OM321 but unfortunately its in German but the translation of the oil section states an SAE 20w/20 for 0 to 30 Deg C ambient air temps and a SAE30 oil if over 30. All in an API of CC

[jenevers]

I have a manual foe the OM321 but unfortunately its in German but the translation of the oil section states an SAE 20w/20 for 0 to 30 Deg C ambient air temps and a SAE30 oil if over 30. All in an API of CC

Thanks for that info. Castrol got back to me and said

The current Castrol recommendation is Castrol Classic XL20w/50.

Being a traditionalist, I'm more likely to go with your recommendation!

[jenevers]

I have a manual foe the OM321 but unfortunately its in German but the translation of the oil section states an SAE 20w/20 for 0 to 30 Deg C ambient air temps and a SAE30 oil if over 30. All in an API of CC

Hi just double checking did you mean SAE 20w/50 when you said 20w/20?

[steamraiser2]

No, Martyn meant 20w20 which is the old descriptor for what we tend to say is SAE20w these days. It is a straight CC grade oil such as Morris Goldenfilm SAE 20. It's not 20/50

[jenevers]

No, Martyn meant 20w20 which is the old descriptor for what we tend to say is SAE20w these days. It is a straight CC grade oil such as Morris Goldenfilm SAE 20. It's not 20/50

Great. Thanks for clarifying.

[jenevers]

I have a manual foe the OM321 but unfortunately its in German but the translation of the oil section states an SAE 20w/20 for 0 to 30 Deg C ambient air temps and a SAE30 oil if over 30. All in an API of CC

Hello again.

Could you let me know if the manual gives any indication of what the oil pressure should be, please.

At 2500 rpm he's getting 20 lbs using SAE 30.

Thanks

Edited June 4, 2015 by jenevers

[steamraiser2]

That is low. It should be around 30-35 psi at 1500. About 40-45 psi at idle when cold. Its not unusual for Mercedes engines to have quite low oil pressure at idle when hot and I wouldn't be surprised for an engine in good condition to show as low as 10 psi at tick over. May I suggest that you check out the oil pressure relief valve as it may not be seating properly.

[jenevers]

That is low. It should be around 30-35 psi at 1500. About 40-45 psi at idle when cold. Its not unusual for Mercedes engines to have quite low oil pressure at idle when hot and I wouldn't be surprised for an engine in good condition to show as low as 10 psi at tick over. May I suggest that you check out the oil pressure relief valve as it may not be seating properly.

Great stuff. I'll let him know about the valve.

He said it went up to 40 on starting but dropped to 10 when warmed up Which sounds about right from what you say is possible. I'll get him to check the rpm at 1500.