oil sample

[wshelton]

Okay, I finally did an oil sample on my DD 671Ns with approx 1,400 hours of fresh water use using 40 wt DD oil, changed about 50 hours ago. The numbers are for port first then starboard. The onan 7.5 later with 1,000 hours. (wear metals) Al 2,10 Cr 0,8 Cu 0,1 Fe 6,45 Pb 0,19 K 0,4 Si 3,25 Na 1,2 Sn 0,1 (oil condition) ST 0,13 OXI 0,0 SUL 0,0 W N,N A N,N F N,N V100 10.8,14.3 onan without the suffics 3,0,1,10,0,0,4,1,0 oil 22,0,0,N N N 12.8. My engines all run very well, no smoke or oil consumption with exception of leaks. Comments, please. The report says No action required and no problems associated with samples etc.

 

[hatterass]

it is best if you get several oil samples over a long period. this will give you a better indecation if something is wrong or going wrong. one sample cant realy do that. if they said everything was fine I would not worry. at the next oil change take another sample so you can then start to compare the ware. I have done this every year for my motors and have a good track record if anything starts to go wrong I can see it in the sample. also nice to have when you are selling the boat, you can show the history and maintance of the boat by the oil samples.
Dave

 

[REBrueckner]

Take your next oil sample at about the same number of engine hours on the oil as this time. Otherwise, prorate readings by elapsed time to make direct comparisons.
See my last post on "oil analyses" here in the last month: (I list Q & A with my lab.)

My last lab said Chrome at 5 PPM was "elevated" at 60 hrs on the oil. A prior lab said 12PPM (for that same engine a thousand hours ago) was ok. They both can't be right!!! 5PPM is considered borderline "elevated" according to one supposedly DD source. But mine came down over seven years !!!!

It seems that different labs draw different conclusions. Call your lab and ask lots of questions...like "what's the standard" for Detroits?? For Onan?" How accurate are the readings? (Two cycle standards are usually a lot lower than four cycle, like Onan.) Get those numbers, if they have them, for each metal. Post if you can!!!

 

[Genesis]

Okay, I finally did an oil sample on my DD 671Ns with approx 1,400 hours of fresh water use using 40 wt DD oil, changed about 50 hours ago. The numbers are for port first then starboard. The onan 7.5 later with 1,000 hours. (wear metals) Al 2,10 Cr 0,8 Cu 0,1 Fe 6,45 Pb 0,19 K 0,4 Si 3,25 Na 1,2 Sn 0,1 (oil condition) ST 0,13 OXI 0,0 SUL 0,0 W N,N A N,N F N,N V100 10.8,14.3 onan without the suffics 3,0,1,10,0,0,4,1,0 oil 22,0,0,N N N 12.8. My engines all run very well, no smoke or oil consumption with exception of leaks. Comments, please. The report says No action required and no problems associated with samples etc.

Ok, this is what I see here.

Starboard engine has higher wear metals than the port. It also has higher silicon - significantly higher. This points to an air filtration issue on that motor.

I would look at how you're getting a lot more crap (dirt, etc) into the starboard motor than the port one, since they're in the same engine room! The genset does NOT show the same silicon (dirt) number either.

While neither engine shows bad wear, the starboard IS wearing faster, and it appears at first blush that its ingested dirt that lies behind the cause. Worth correcting if you can.

 

[wshelton]

Thanks for the response. Karl, this one is for you regarding the starbord engine and dirt. I, like you am puzzled why with both engines in the same location. However, the port engine has an oil leak at a fitting almost impossible to get to to fix, thus I catch the discharge and replenish with fresh oil. I would estimate a gallon about every 4 to 5 hours. Thus this engine oil always looks almost like a gas engine oil unlike diesel is black almost immediately upon a change?

 

[REBrueckner]

On another message board, Trawlers and Trawlering, a post was made several years ago by an experienced mariner. He had contamination in NEW Exxon Mobil oil! I discussed the situation with him in direct e-mails to be sure I understood the situation, as contaminants in the oil brand I use scared me a lot.!!

To make a long story short, a big corporation tried to avoid their responsibnility so he took them to court where subsequent misbehavior and lying was uncovered. So instead of a small settlement, the judge ordered a major corporation to give him new engines...which he got!!!

 

[Genesis]

Thanks for the response. Karl, this one is for you regarding the starbord engine and dirt. I, like you am puzzled why with both engines in the same location. However, the port engine has an oil leak at a fitting almost impossible to get to to fix, thus I catch the discharge and replenish with fresh oil. I would estimate a gallon about every 4 to 5 hours. Thus this engine oil always looks almost like a gas engine oil unlike diesel is black almost immediately upon a change?

Uh, that's a BIG difference, and accounts for the entire issue. Did you note it when you sent in the samples? If not, you can't count on the results meaning anything!

 

[wshelton]

Karl, I did not note that issue on the replenishing of the oil, however the starboard engine results would seem accurate based on original oil,which when last changed was not really done thourghly due to my pump failure and not getting all the old oill out. Oh well, I am confortable with the fact there is no antifreeze and other apparent major problems lurking in the background. Thanks again.