Oil analysis and Survey

[MilesAwayOffshore]

We are having a survey done on our prospective boat. Can the surveyor tell if the oil has been changed in the last few days in the hopes of a positive oil analysis?

Thanks for any advice!

 

[Comodave]

Welcome aboard. Most diesels will turn the oil black within a few hours of being changed. So if it has been changed and not run very much the oil may still be clean looking but if it has a few hours then probably no way to check it visually. Look at the oil filters, most shops write the date and hours on the filters. Also look at the filters and see if they are spotlessly clean.

 

[MilesAwayOffshore]

Thanks for that. We have also booked an engine specialist to go over the engine as it has just over 4000hrs on the clock. Would it be fair to say that a pre-purchase inspection should pick up anything that may be trying to be covered up? Given the hours on the engine, we want to make sure that it has been well looked after and we hopefully won't be up for a rebuild within the first few months of ownership.

 

[Comodave]

Maybe, maybe not. Depends on what is wrong with the engine. What engine are you looking at? An engine with 4K hours is probably going to run ok. I would be more worried if it was really low hours.

 

[MilesAwayOffshore]

It's a Cummins QSM11, 610hp

 

[Comodave]

I have 6CTAs in my boat but don’t know anything about that engine.

 

[mvweebles]

Good articles on engine surveys and oil analysis. Steve D is incredibly knowledgeable and a prolific writer. His website is a trove of useful information.

https://www.proboat.com/2013/05/reading-oil-analysis-reports/

https://stevedmarineconsulting.com/the-art-of-the-engine-survey/

Good luck

Peter

 

[Bacchus]

I would request maintenance records and be skeptical if none were available.
Most owners keep maint records, receipts or a log. When they won't share them it at least leaves doubts???

 

[SaltyDogg]

I would request maintenance records and be skeptical if none were available.
Most owners keep maint records, receipts or a log. When they won't share them it at least leaves doubts???

Maybe it's the Friends I keep, almost no one I know have good maintenance records, I generally start with the intention of keeping records but that normally stops a few months after the new wears off, the only record keeping I do all the time is writing the date and hours on filters when i change them.

 

[Bacchus]

Maybe it's the Friends I keep, almost no one I know have good maintenance records, I generally start with the intention of keeping records but that normally stops a few months after the new wears off, the only record keeping I do all the time is writing the date and hours on filters when i change them.

That's too bad... I think it adds value not only for my own peace of mind but actual $ value when selling.

 

[C lectric]

I keep records and have done since the very early days of my boating.
THey are not fancy, nor pretty, and are done on paper kept in a 3 ring binder.
Started long before P.C. s were affordable, even existed. Never saw the need to change.

They include a history of oil reports for the engine going back to 1991 and the gear box to about 2,009.

But they are there. And yes sometimes they have saved me a bunch of work as it is easy to look up what and when you did the work and the parts used.

I usually do not track the hours accurately though as those are simply what they are.

I do accurately track hours for some very specific jobs like a couple of insurance claims I had, one my shed falling on my boat, the other an errant sailboat that lost reverse and punched out several windows and damaged some of the woodwork.

Personally I would look askance at boats that have no records as that simply means to me a lack of caring and may mean little to nothing has been done for LONG, TOO LONG intervals between mtce.

Harsh I guess, but a boat is a lot of money, at least to me, to purchase and maintain so the P.O. should make a serious effort to track what is done and when.

 

[omoore]

Four thousand hours is a lot so be sure to pick a thoroughly knowledgeable tech who is familiar with your particular engine. It would be very useful to know how the PO operated the boat--in particular what was his cruising RPM. Pleasure boat ratings can be wildly incorrect. For example, I had three 8-V92TA engines blow on my 58ft MY. Two just under 1,000 hours and one at 1,200 hours. I spoke with the chief engineer at Detroit Diesel. Explained that when transiting to and from New England and Florida we followed the manual, back off 200 rpm and ran from sun up to sunset. When I told him the displacement was 65k he said no wonder the engines didn't last. You should have been sticking to the commercial rating and not exceeding 1,600 rpm!
It would be costly to do a compression check so the next best thing is oil analysis. But as you questioned without a substantial number of hours, the results won't tell you anything. Now you are down to the basics: temp checks, leak checks, listening with a stethoscope starting and warming up, color of exhaust and absence of oil sheen on water. Bottom line, the price should reflect the high hours.

 

[BroadCove]

In addition to hours, another key factor (arguably more important) is the amount of fuel that has been used. There's no way to learn that directly, but if the boat has a semi-planing or planing hull, it's worth assuming much more fuel has run through the engines than a displacement speed vessel. I have twin QSM11 661 hp engines. 2005 boat, purchased with about 900 hours. I've put about 250 hours on them in the past year. Knew when purchasing that I was going to have a major service at 1,000 hours, and it was - more than $20k including rebuilding the aftercoolers.

On my hull, at 800-850 rpm, I'm making hull speed and burning about 2.5 gallons per hour per engine. 4000 hours = 10,000 gallons at that burn rate. But I usually run at 2000 rpm, making 21 kts and burning 21 gallons per hour per engine. 4000 hours at that burn rate is 84,000 gallons.

Lots of good info available on these engines from Steve D as referenced above.

 

[Steve DAntonio]

Provided the reports are reviewed by someone who has been trained to interpret them, few mechanics are, then it should be obvious if the oil is new. Used oil usually includes iron, and copper in the wear metals section, if those are 0 or near zero, then the oil is almost certainly new. Also, the TBN starts at about 10, if it's still there or at 8 or 9, th oil is probably new, if it's 2-5, it's used. Peter already posted these but there they are again, more here https://stevedmarineconsulting.com/wp-content/uploads/2014/03/FluidAnalysis143_Final.pdf

The importance of getting a good engine survey, and surveyor, cannot be overstated. More here https://stevedmarineconsulting.com/the-art-of-the-engine-survey/

 

[bumpkin]

My surveyor couldn't tell

We just had a boat surveyed that was advertised as having the oil changed. Our surveyor couldn't tell if the oil had been changed. There were only 15 engine hours since the oil was changed per the seller. The surveyor said he couldn't tell and wanted the oil report to come back to see what was going on.

As mentioned earlier the the oil of a diesel engine turns black quickly. Good luck with your new boat.

Mike

 

[North Baltic sea]

Hi,

an interesting cultural difference in oil analyzes. In Europe, it is not very common to analyze oils in consumer segments. Usually oil analyzes are done in the industry. Have you ever had any real benefit from doing tests on your boat’s oils or is it just comfortable.

NBs

 

[Leo Reise]

By all means, have the engine inspected by an expert mechanic and the oils analyzed.
New to Diesel engines when we purchased our trawler, I was concerned with engine hours.
When we purchased our boat, the engine, Ford Lehman SP135, had 3800 hours. The first thing the mechanic said was “it will be broken in soon”. He went on to say that if the engine care has been taken, oil changes, filter changes etc, these engines have records of 10,000 hours an more.
Now I am no expert but from reading over the last three years, I have come to the conclusion that Ford Lehman’s longevity does not appear to be unique to comparable Diesel engines.

 

[mvweebles]

Hi,

an interesting cultural difference in oil analyzes. In Europe, it is not very common to analyze oils in consumer segments. Usually oil analyzes are done in the industry. Have you ever had any real benefit from doing tests on your boat’s oils or is it just comfortable.

NBs

There have been several posts by newbies about oil analysis showing something unusual, so yes there are examples of practical benefit. The Steve D article (and his post) further describes you can even gleen information from an analysis when you know nothing about the oil, or when you suspect an owner may be trying to hide a defect with a recent oil change. That's a lot of benefit from a $40 test ($US of course).

For a typical 300hp engine of fairly recent vintage, an in-frame partial rebuild probably starts at about $10k-$15k and goes up pretty quickly from there. Transmission will likely be in the $5k on up range by the time the dust settles. Again, $40 may not tell the whole story, but is a valuable start.

I can't speak as to why it's not common in Europe. It may be more effort there, but I wouldn't let that be a deterrence.

Peter

 

[NEtrawler58]

That's too bad... I think it adds value not only for my own peace of mind but actual $ value when selling.

There is a separate thread specifically on the subject of record keeping. Seems that TF members range from no records at all, to very detailed and specific logs, not only of maintenance but of boat usage and trips.

Personally, I keep a basic Excel spreadsheet of all maintenance as well as upgrades/repairs/replacements. I also keep a binder with paper receipts and invoices. Takes almost no time. Hoping the next owner might appreciate it.

 

[C lectric]

Hi,

an interesting cultural difference in oil analyzes. In Europe, it is not very common to analyze oils in consumer segments. Usually oil analyzes are done in the industry. Have you ever had any real benefit from doing tests on your boat’s oils or is it just comfortable.

NBs

Testing oil warned me of a problem twice.
--Once was salt [ sodium] in the gear oil which meant a cooler leak. It turned out that I had contaminated the sample but I cleaned up what I was doing, my mistake, and it is now reliable and no sodium.

--the other time it meant business. Diesel fuel in the engine oil. I waited a while and did another test. The same result, fuel in the engine oil.
THere were other signs such as slightly lower oil pressure at the same revs but it was not clear enough to act.

The two oil tests each showed the problem. I was approaching the level of engine damage. It was one or more leaking injectors. THey were truely due. The shop told me the O rings could not be pulled of in one piece but rather many pieces.

WHile at it I pulled the injector pump, actually was the first thing I did just in case. THe shop found some minor damage for a repair bill of about $1,200 Cdn. I was told though that had I left it much longer my pump would no longer have been repairable. Rather replacement at about $5,000 Cdn.

So at least to me it was more than worth the cost of the tests.

Hopefully it never shows a problem but do you want to bet.

I will admit I had some work experience on some very expensive machines so I saw the value at work.

THe tests are also worthwhile as an after the repair check to ensure the problem you repaired was not masking something else.

 

[ronobrien]

I would request maintenance records and be skeptical if none were available.
Most owners keep maint records, receipts or a log. When they won't share them it at least leaves doubts???

It's interesting that in this same issue of TF there is thread about maintenance records. Many of the contributors say that they do the work but don't keep very good records. A lack or records doesn't necessarily mean the boat wasn't maintained. Look for other indicators, dates on filters, any history of oil analysis, talk to the owner and get a feel for them, the general condition of the engine room, spares on board suggest someone that is at least prepared to do maintenance, etc. Good luck.

 

[ktdtx]

If you can get a "real" Cummins Tech. I believe they can hook a laptop to that engine and check a lot of things you can't see/hear. They can give readouts of how the engine was run-hours at different RPM, etc plus a Cummins Tech has resources further up the "food chain" if anything is questionable.