Oil change

[[2574]]

I have always previously used professionals to service my Yanmar 4JH2E. The oil level has always been way over the full mark - maybe half an inch to an inch over the top mark on the dipstick. I've done the oil change myself this year and have filled to the top mark only. Have I done right or is there some mysterious reason that you should always overfill a marine diesel with oil? I'm thinking that maybe its to do with engine operation when heeled - extra oil needed to keep the reservoir operational at 30deg heel? Or maybe they always lashed in a load of oil to avoid spending time looking at the dipstick? Any thoughts?

rob

 

[johnalison]

You've done the right thing. My engineer fills to above the mark because he knows that half a litre will be taken up by the oil-filter and the level will then be correct. I am sure the engine-manufacturers know what they are telling you. Surplus oil can damage the engine.

 

[PeterGibbs]

I have never heard of an engine failing for having its oil level between the marks - heeling is taken into account in the design. I think I'm right in saying most engines will continue to work ok without damage when the oil level is shy (not way off) the bottom mark. Way over the topmark risks damage to the engine.

PWG

 

[webcraft]

[ QUOTE ]
I have always previously used professionals

[/ QUOTE ] - a potentially dangerous practice as well as expensive . , , ,

Same answer . . .

Overfilling an engine with oil is more likely to damage it than underfilling it.

Fill to top mark, run engine to fill new filter, add small amount of oil until back up to top mark.

- N

 

[Guest]

[ QUOTE ]
I have always previously used professionals to service my Yanmar 4JH2E. The oil level has always been way over the full mark - maybe half an inch to an inch over the top mark on the dipstick. I've done the oil change myself this year and have filled to the top mark only. Have I done right or is there some mysterious reason that you should always overfill a marine diesel with oil? I'm thinking that maybe its to do with engine operation when heeled - extra oil needed to keep the reservoir operational at 30deg heel? Or maybe they always lashed in a load of oil to avoid spending time looking at the dipstick? Any thoughts?

rob

[/ QUOTE ]

Many engines actually have a max heel figure .... my Perkins states just over 30 degrees ... depending on sump pan fitted and oil pump. Suspect if people check very carefully in their manuals they will find a reference to something similar.

As to overfilling oil ... it is a dangerous practice if its still overfilled after filter has filled up..... on change of oil. Why ?

Oil can force it's way up past the rings and engine can run on the oil. I know - I've had it happen and there is no way to stop the engine. Stop controls / fuel levers etc. are redundant cause its getting fuel another way. OK it is prevalent with older engines where small amounts of diesel may find way into sump due sticky rings etc. - but can happen.

IMHO - you have done right ... Max mark is Max - engine manufacturer must have reason for it !

 

[Skyva_2]

Another reason for maintaining the oil at the max mark on the dipstick is that it is easier to monitor the level - if it goes up there may be water getting in, if it goes down there is oil burning or a leak somewhere.