MEP 831A Oil Filling Procedure

[selkirkcraig]

Just received two low hour MEP 831A Gen Sets with no crankcase oil. Plan to fill with Rotella 15/40W. Could someone please give the correct procedure for filling. The manual calls for filling through the dipstick port. But what is the Yellow cap marked "oil" for on the top of the engine?

 

[justacitizen]

I changed my post to be more helpful. sorry try this link it has some download manuals that are very helpful
https://www.steelsoldiers.com/showthread.php?132681-MEP-831-FAQ-for-owners-or-potential-buyers

 

[Kenny0]

If it was mine, I would fill with the port that was the easiest. Just keep in mind that filling through the top port especialy on a cold engine it would take a little longer to get an accurate reading on the dipstick until the oil runs down into the crankcase.

 

[DieselAddict]

Don't fill the top cap. Fill through the bottom cap where you check level.

 

[Kenny0]

Don't fill the top cap. Fill through the bottom cap where you check level.

I could be wrong - the reason?

 

[DieselAddict]

The top cap is not an oil fill cap. It is a starting aid. You'll need to look in the Yanmar engine manual for instructions how to use it. Recalling from memory you would remove the cap and put a few drops of oil in there if the engine wouldn't get going normally.

Always add engine oil to the bottom caps.

 

[justacitizen]

I could be wrong - the reason?

i am not sure but on some of the yanmar engines there is a port in the head you put a small amount of oil in as a cold start aid. could the yellow cap be this??? in reading the above thread they all say to fill to the bottom two threads in the port in the engine block and to ignore the dipstick.

 

[Kenny0]

The top cap is not an oil fill cap. It is a starting aid. You'll need to look in the Yanmar engine manual for instructions how to use it. Recalling from memory you would remove the cap and put a few drops of oil in there if the engine wouldn't get going normally.

Always add engine oil to the bottom caps.

I stand corrected.

 

[selkirkcraig]

Thank you all for the input. As per the manual I certainly will fill through the lower dipstick port. It is interesting that I have not found any solid information as to the purpose of the large yellow marked "oil" cap on the top of the engines. My engines per data plates are 06/08, no Tier 2 plates. I have to think that the purpose is for an aid for cold start.

 

[DieselAddict]

I stand corrected.

We're all here to help each other.

 

[selkirkcraig]

Yes Sir. This site is really great. I appreciate the information available by it's members.

 

[Kenny0]

Did do a little research. None of the TM manuals showed the big yellow cap on top of the engine. Only thing I found was preheat for starting and compression release for hand starting. Did a search on L70AE engine and some show the big yellow cap on the valve cover and some don't. If you take the yellow cap off, you should be able to see the rocker arms valve springs and maybe the pushrods. Putting a little oil here imo would not not do anything for starting and I think my first post would apply. Could be a production change or engine has been replaced. Do what you are comfortable with. Maybe someone could verify.

Edit
Rubber plug on edge of valve cover is cold start assist 2 cc of oil.

 

[DieselAddict]

I was trying to find examples of the different ones but I didn't make it before falling asleep last night. I'll poke around some more if I have time today.

 

[Dewie38]

The yellow cap on the top of the engine is a fill port added to the cover later on in production due to the fact that the process of filling through the dip stick was a pain and messy.

 

[DieselAddict]

Hey Dewie, I'm not able to find when that was added in any of the engine manuals available online. Was that something added for this application or was it a running design change for Yanmar?

 

[Dewie38]

Diesel
I think Yanmar added the cap after complaints we received from the field that oil changes were difficult to perform.
This was done shortly after we went into production in 1997.
There are several things on this engine that you wont find in a Yanmar manual such as the 24 volt starter, the increase in the engine fuel setting, the timing change and the use of two 12 volt air intake heaters for 24 volt operation.
As far as the oil fill cap being incorporated across the line of engines, I don't believe so but I could be wrong.

 

[dav5]

One of my 831A's came with the Warranty Handbook and Operators Manual sealed in plastic from a 2011 Reset that had 2.2 hours on it. Even though it is in 5 languages it is pretty sparse as far as information is concerned. The only mention of the start assist is in a diagram where a "black plug" is shown and a diagram showing an oil can pointing to the corner of the "valve rocker arm cover". It states "in cold weather, when your engine is hard to start, remove the rubber plug of the rocker arm cover and add 2 cc of engine oil before starting". There is no black plug on my unit but on one corner there is an area where it looks like it would go.The top yellow plug in the valve cover is not shown or mentioned even though it is on the engine. I filled it the first time using the lower hole and made a mess. Since then I have been using the top hole. I'm pretty sure it has no function as a start assist. The oil flows down to the lower hole fairly quickly.

 

[dav5]

Here is a photo Cord posted [#9 in the MEP831 FAQ for owners thread] showing the location of the starting aid hole with the cover off. It is on the corner and desn't seem to connect with the valve area.

 

[Dewie38]

We never used the start assist on this engine.
Any early engine that had the assist plug in the cover was cut off and glued into the cover.
The yellow cap is only for oil fill.
Servicing the engine proved to be very difficult and messy using the oil dip stick for the GI's in the field.
So we had Yanmar add the cap in the top cover

 

[Kenny0]

This is a case where a picture would have made a difference. Like a lot of people say to include pictures. hint hint