Oil Analysis lessons

[REBrueckner]

Not that anyone needs convincing about lube oil analyses, but here is a current unfolding story.
During the survey of 1976 Cummins 903 VTA's we got an oil analysis on one engine with the following SEVERE readings. We do not know the hours on the oil, but it's likely been sitting mostly unsued for three or four years. In the Chesapeake Bay area. The other engine had all normal readings:[all in parts per million]
Iron, 456
Aluminum 70
Copper 200
Sodium 453

Other readings had some high results warranting 'monitor' .

So I called the lab and spoke to an ex navy mechanic, now working for the lab on analysis of test results. Here are the notes I made:

" Recommends NOT running this engine as test results indicate SEVERE wear and existing engine damage. The wear metals indicate bearing and or bushing wear and the extremely high sodium suggest s either antifreeze and/or raw water intrusion. Heat exchanger as well as head gasket leaks could be at fault.

The standards against which these readings are based are statistical for a range of Cummins engines not specifically for Cummins VTA 903 nor specifically marine engines. The indicators in the report are based on standard deviations for all Cummins engines they have tested. [This is common, not unusual.#]
These wear metal [iron, aluminum and copper] and contaminant metals [sodium] are entirely out of normal range and running the engine for the 50 hours I mentioned back to CT is ill advised. The lab normally see potassium and sodium levels at about the same levels, as is presented in the port engine.
Total Base Number of about 6 [under fluid properties] reading is normal and indicates the acid control of the oil, the alkalinity of the oil, remains in the satisfactory range. This oil [Rotella T 15W 40] originates with a TBN of 10."

So I called back and asked: "Do you think the wear metals, the first three severe readings, and the sodium level are related?

"Sure: Without any doubt the extreme sodium reading has caused the out of normal wear readings.

What about running that engine for about five hours to get to a repair facility?
" Can you have the boat towed?' OMG!!!!

So I called the prospective buyer, a friend, and told him: If you plan to run to the repair marina, we should run on one engine after leaving dockside. We can restart the damaged engine for maneuvering for a few minutes to get dockside at the repair facility if required.

Next step: we get advice from a certified Cummins mechanic at the reapir facility.

# I reported similar baseline comparisons for my own 8V71TI oil analyses [different analysis laboratory] maybe 6 or 8 years ago in these forums. Turned out back then, and still seems the case, such engine wear and contaminant levels are proprietary.

Will post subsequent developments as they unfold.

Comments, insights welcome.

 

[REBrueckner]

Today 10/10 we find out from a confidential source the starboard Cummins with the bad oil analysis experienced a 'riser failure' some unknown time ago.

I explained to my friend, the prospective buyer "I never heard of water [sodium] intrusion in oil from a riser failure without the need to rebuild/repair, at a minimum, some aft cylinders, rings liners, whatever. I'm still thinking it's more likely there is some sort of current problem....head gasket or oil cooler leak....A pressure test of the cooling system via the fill cap on the heat exchanger expansion tank is a quick and easy test to get a preliminary look."

Any criticisms or alternative views?? I'm pretty sure the buyer is likely to get a certified and well recommended Cummins mechanic aboard for a detailed survey after the sellers are made aware of this mess. I suggested the buyer ask the mechanic if it's smart to get the oil changed BEFORE we do a sea trial....get rid of as much of the nasty sodium as possible.

 

[Dan Mapes]

I would certainly change the oil. We have been running 671TIs since 1999 with some of this. How long this engine will keep ticking is anyone's guess. I am thinking this is a gasket issue in our case. The 71's have a mess of them between the head and block.

View attachment 16340

 

[drburke]

Seems to me to be a straightforward distinction between what's happened in the past, possible damage done, and any ongoing issues.

You now have a baseline, so I would change out as many fluids as possible and gingerly try to get a few more hours on and retest.

My surveyor had recommended such an approach to me because of unknowns with previous maintenance.

DAN

 

[rsmith]

Said it before and I'll say it again. I don't have very much faith in oil analysis. There are too many variables in how the sample is taken and other factors right down to the sample bottle and how well the guy in the lab cleaned his equiptment between samples. If it's going to show anything at all sampling needs to be over a long period of time and done at the exact number of engine hours between samples. Even then how the engine is operated between samples can throw things off. If it makes you sleep better at night fine but in IMHO you might as well do a Jesse Pinkman and start chucking cash out the window.

 

[MikeP]

Concur 100%!

Unless they are done as part of a regular program, they are hugely overrated. In this particular case, I'd pay no attention to it at all. Normal mechanical checks/observation/oil change is all I would do and unless there is some obvious problem, start 'er up and go from there.

 

[GJH]

All that stuff got in that oil somehow and I doubt it was a gift from Santa. To completely ignore it would be foolish.

 

[krush]

A guy name Don Bentley (of Bently Nevada) came up with a new way to measure shaft position (and thus vibration) on rotating machinery like 50 years ago. Today his stuff (in one form or another) is on any piece of valuable equipment. It will tell the position of a shaft in a bearing down to the 0.0001".

The funny thing is, some machines that ran fine for 50 years all of a sudden become problem children and huge headaches after the new monitoring equipment was installed. Engineers would freak out and wonder how the equipment hasn't blown up.

Data is great, more data is better. But somebody with a brain still has to draw useful conclusions from the data. For those without the brain, ignorance (no data) is better.

 

[REBrueckner]

The story continues to unfold: Our final lab report on the suspect STB Cummins 903VTA 450 HP engine.

Based on previous discussions in these forums, we had a ferrography report prepared to see if small iron oxide particles from extended lack of use might be a culprit. If such small particles are scraped from cylinder walls and removed via an oil change, such could could be a minor and temporary contamination issue.

The ferrography reported overall SEVERE [RED] not surprising since the lab used the same sample.

The ferrography reports states [and includes magnified microscopic pictures] :

"Suggest flushing system. Suggest inspecting this unit for excessive wear and/or pitting. Severe red oxide (rust) contamination is likely from a heavy water contamination source - judging by the high Na content it is suspected to be a salt water contamination source but this is speculation. SEVERE amount of ferrous rubbing wear. Excessive rubbing wear results when
abrasive particles (silica/dirt and environmental contaminants) are present. Severe amount of abrasives (silica/dirt and environmental contaminants), which cause component wear. SEVERE amount of red oxide (rust) possibly resulting from external contamination. Red oxide particles are abrasive and increase component wear. Significant amount of cutting wear particles, which is the result of excessive abrasive particles (silica/dirt and environmental contaminants). Significant amount of lead/tin alloy, likely from bearing wear. Moderate amount of fatigue wear. Fatigue wear results from cyclic stress and metal fatigue. Fatigue wear is not common for diesel engines, and may indicate cam/roller rocker wear or oil pump wear. Moderate
amount of copper alloy particles."

Not a single GREEN reading resulted which is NORMAL. { Oh darn,if you get my drift!}

WEAR METALS [range is in {EDIT} microns] [I originally posted "ppm"]

Rubbing 800-1000 RED [SEVERE]
Fatigue 5-40 YELLOW [ABNORMAL]
Cutting 4-60 ORANGE [MORE ABNORMAL, not SEVERE]
Ferrous 1-60 RED
Cu Alloy 25-140 YELLOW
Pb Alloy 5-40 ORANGE

CONTAMINATION METALS
Abrasives 1-130 RED
Red oxides 1-130 RED

I've never seen such a report before so will again call the lab this week for additional feedback. And will report what they have to say. I'd like to get a separate lab analysis person and compare comments with the first.
Right now what concerns me most is the possibility of excessive bearing wear. Any interpretations, suggestions are welcome.

 

[tpld3]

It is at least very useful to know of high sodium in the oil as well as the high iron, whether or not oil testing is done at "scientific intervals". Knowing this information warrants further investigation to prevent possible cataclysmic failure of the engine.

 

[MikeP]

Are you going to interpret that sample as a correct indicator of the engine condition and do a complete teardown/rebuild since that is what the oil sample results would require (rings/cyl walls/bearings)?

As you noted earlier, issues with head gaskets/coolant/raw water intrusion can be easily diagnosed with various mechanical tests - leak down, etc. Further, as Krush pointed out, in the past, when nobody worried about oil samples, engines were run until they gave some sign of a problem and they were then diagnosed and repaired as necessary.

As I said, there is no way I would take that one time oil sample as a statement of engine condition on it's own. It MIGHT be correct but I would do the appropriate diagnostics - leak down, compression, etc and go from there. An oil analysis is just one diagnostic tool in a rather large tool bag. It provides some information that has to be considered along with the rest of the diagnostics.

If the engine had been running regularly and getting regular analysis and suddenly showed up with out-of-tolerance readings, that would be a very different thing but IMO, this calls for a lot more diagnostics.

 

[SeaEric]

Obviously - change the oil and filter then proceed. But....how does it run? Will it start up from cold? How does it behave? How did it sea trial? Did it make RPM's and proper oil pressure (hopefully on a mechanical gauge) and not overheat? Is there something special about this particular boat or deal that has so far prevented the buyer from running away screaming? Inquiring minds want to know. As stated, a stand alone single oil analysis doesn't prove much. One more question? Does this boat have an oil change system? I have seen quite a few contaminated oil samples coming from pumps and manifolds in oil change set ups when oil is pumped out and then back in using tubes, pails and buckets and God knows what was in there before.

 

[REBrueckner]

"Knowing this information warrants further investigation to prevent possible cataclysmic failure of the engine..."

OMG!!!....Ahhhh...PUH-LEASE go lightly with words like "cataclysmic" [or "catastrophic".....] I am getting older every day and may be subject to heart palpatations with such language. I already told the propsective buyer
"This boat is really cool, I may not speak to you again if you don't get it."

"....how does it run? Will it start up from cold? How does it behave? How did it sea trial? Did it make RPM's and proper oil pressure (hopefully on a mechanical gauge) and not overheat? Is there something special about this particular boat or deal that has so far prevented the buyer from running away screaming? Inquiring minds want to know.

Stb ran fine, except for low idle RPM and some stalls as a result. A few days earlier started for haul out faster than my old 8V71TI's.... turned up 2400 RPM under load on sea trial, same as port engine [which had all good oil analysis] vs rated RPM of 2600...all gauge readings and manual survey temperature readings were normal. Buyer has negotiated so far to 40% of asking price based on poor electric, equipment not working and general condition as well as knowledge of prior offers. 30KW ONAN and 11KW Fischer Panda have excellent oil analyses....latter overheats, likely a simple issue....Interior quite good,fit and finish and teak trim and cabinetry exquisaite. Notches above my Hatt. Aluminum hull excellent based on 250 ultasounds and recent topside awlgrip....

Ques remains is the boat even worth 40%....barely, if at all, in my opinion.

Requires somebody with the patience and affection to restore it. Like you nuts!
25%-maybe 30% of asking price?? and there may well be a deal. Awaiting seller reply about engine SEVERE tests. Owner deceased; family seller almost certainly in shock; knows nothing about boats.

"...Are you going to interpret that sample as a correct indicator of the engine condition and do a complete teardown/rebuild since that is what the oil sample results would require (rings/cyl walls/bearings)?.."

I'm not there yet....but my friend the buyer may be. Unsure of ferrography interpretations yet.I decided to post about this saga....because of all the uncertainties associated with a used/unused boat....and all the issues which are discussed in these forums year after year.

As I suspected at the start, this is unfolding as an interesting case study. I suspect the prospective buyer will have a Cummins mechanic come down and do a more detailed engine survey.

"As you noted earlier, issues with head gaskets/coolant/raw water intrusion can be easily diagnosed with various mechanical tests - leak down, etc.."

Personally, I'd buy a pressure testing pump gizmo, pressure test the cooling system via the expansion tank and see if it holds 5-7 lbs pressure...what, maybe 5 -10 minutes?? If it doesn't, then test the heat exchanger, oil cooler, individually.....I'd change the oil and run both engines fivehours or so to the repair facility; test the oil again.... but then it's not my $$ at stake....
to be continued....

 

[REBrueckner]

"Does this boat have an oil change system? I have seen quite a few contaminated oil samples coming from pumps and manifolds in oil change set ups when oil is pumped out and then back in using tubes, pails and buckets and God knows what was in there before.

yes... There are so many hoses and cables we never got to figure out how it is currently plumbed. Previosuly, maybe a 25 or 30 gallon auxiliary tank which held clean lube oil, filled via deck fill, which could be directly fed to the main engines. Old oil was pumped directly into fuel tank for mixing with fuel and burning. That system is at least partially disconnected and plugged off. The lube oil tank is still there and I would guess feeds each engine....but we did not trace the valves or pumps that might be involved.

Why not run away screaming? [SeaEric]
Aha, a skeptic!!!
reasonable question: Because she is so like a very pretty girl!

One reason is that the hull and interior was completely refurbursed in the early 1990's by boatyard owner, an aft enclosed salon and a third stateroom aft added. Naiad stabilizers were added and these are not operational now...maybe it's just a dirty control solenoid.... ?? Great layout.

I asked my friend "If they sold you the boat for $1, would you take her? And we agreed that would be a great deal. [perhaps we should know better?]

Anyway, I said, "so the issue then is price, right?" and we agreed at the right price, this boat would provide him an extremely comfortable live aboard and a great yacht for subsequent cruising. Not for profit, but a fascinating opportunity to own a vessel that new would be around $4M-$5M new.

All that could be illusory of course, like the pretty girl.

 

[SeaEric]

Is the subject vessel named "Gypsy" ? If so, we sold her to the dead guy many years ago. I may have an old file with OLD info.......Not sure if it would be of any value.

 

[carolinacoast]

Could you have a mechanic boroscope the suspect engine for any internal damage?

 

[REBrueckner]

"Could you have a mechanic boroscope the suspect engine for any internal damage?"

I guess that's a question we'll ask the mechanic if we get to the next stage....

I don't know the range of things that can be assesed with a borescope....
so far it's the presence of metal contaminants that appear to have affected pistons/rings/liners and separately bearings. Seems like the former might be assessed, not so much the latter??

Here is a description I found online:

"A borescope gives you an opportunity to find defects that might not otherwise be detectable by a compression check. Things like glazing or scoring of the cylinder wall. Corrosion of the cylinder can also be identified through borescope inspection. And a borescope inspection can verify (or eliminate) possible causes of low compression readings.

Tips On Borescope Use
Dyer shares some tips on using a borescope to inspect your engine. "One of the most important things is to know the power of your borescope. This is very important. Not too long ago, a guy handed me a borescope, and I used it to look into the cylinder. What I saw was a gouge in the cylinder wall that looked like the grand canyon. If a mechanic didn't know he was looking at this apparent large defect through a 15X borescope, he might make a rash decision to remove the cylinder."

During your inspection, you can view the piston crown and cylinder walls, and cylinder head for defects including scoring, corrosion, and cracks. You can also inspect for conditions like ring damage and evidence of excessive blow-by. Intake and exhaust valves can also be inspected. This can help verify a problem (or eliminate the possibility) without having to disassemble the cylinder..."

http://www.aviationpros.com/article...on-getting-the-most-out-of-this-valuable-tool

 

[Boatsb]

Did you get the survey from the internet too?

You seem so intent to use the internet as your primary expert yet wont bring a good mechanic to do a complete engine survey.


Get a mechanic you trust to go over the engine. use the oil analysis as a tool not a definitive indicator.

There is no need to go over the definition of a borescope for us. No need to post someone else s conclusions of unrelated machinery like aircraft either. Either get it checked out or dont but posting 5,000 words of basic explanations of what your doing is not necessary.

 

[MikeP]

Ouch!

 

[REBrueckner]

"....yet wont bring a good mechanic to do a complete engine survey."

Maybe I did not explain the unfolding sequence of events clearly:

Unless the sellers are willing to entertain a further reduced offer, the prospective buyer does not want to go to yet another survey since the current preliminary price agreement assumed satisfactory engine analyses. Surveys get expensive real fast: Roughly 7%-9% ballpark of the purchase price because of circumstances.

If you have an understanding of the value and limits of borescope testing and how it might relate to a subsequent engine teardown, if at all, THAT would be helpful. Editorial comments notso much. The fact that borescopes are also used to test jet engines is immaterial. I'm hoping someone who had one done will comment on their experience. We have no idea what such might cost.

We are also not familiar with borescope testing which is why I posted a brief description, but have provided a recommended Cummins certified mechanic the oil analysis and ferrography report...and will likely proceed as he recommends if a price accomodation with the seller can be reached. We will be asking the mechanic if a borescope test is worthwhile. That comes up this week, we hope, and whatever the outcome, I'll post results.

One reason we did not start with a Cummins mechanic is that several people supposedly familiar with the boat felt the prior owner was very careful with them. And until we got to the boat location we had no recommended mechanic within reasonable proximity.

Anyway, things often don't unfold as expected....That's the situation here and why it may be instructive to some. A reason for starting this thread is to share alternatives, approaches, and unfolding incomplete information because so many here attempt to purchase used boats and may be faced with similar circumstances. And of course we hope to get feedback and suggestions from the experiences of others.