Engine Surveys

[Seevee]

Lots of talk on Engine Surveys.....


So, lets discuss this a bit,


First, how much of an engine survey do we need?


I would bet that, for the most part we would need: (simple stuff)

Overall inspection, fittings, oil leaks, mounts, etc.

How easy does it start
Color of smoke coming out after start
Run smooth and run up to full RPM, under load
Oil analysis check (Mainly for water, fuel...)
Temperature check
Alternator output



Now, if it's a more current engine low time (less than a few thousand hours) do we need to get into things like:


Crankcase differential pressure check
Boost Pressure on turbo
Boroscope of cylinder walls
Compression check


Comments?

 

[Max Simmons]

Smoke disappears in one or two minutes MAX? That may eliminate a lot of Perkins and Lehmans

 

[C lectric]

I agree so I should have mentioned that. THere are some engines that will smoke untill they get a load on. Cold combustion chambers will not burn fuel well creating a lot of smoke.

I will Mod. my comments.

My edit attempts dumped half my comments so I will redo and post later.

 

[C lectric]

My redo. I did sort of goof and then lost about half.

Generally:
--yes, oil tests of engine & gear. Not definitive unless something is really wonky. If the owner has a series of oil tests that would be a bonus.

--owner should have records of mtce done. Maybe not all receipts except for major work. Hopefully also should have the manual

--general appearance good. Not spotless but not totally rust covered either.

-- engine cold startup. Off for one or two days. The engine should start quickly not quite roaring to life and settle to a smooth idle quickly. Some engines will smoke when cold, maybe a lot., until they get a load on them. Means be ready to cast off quickly after the initial start, all unneeded gear already stowed, no long warmups, just enough to get past the initial startup instability . Get moving and get a load on the engine. As the engine warms up the smoke should disappear. These older engines , designed 40-50-60 years ago didn’t have to worry about the pollution regs we have now but they can be good engines still.
The reason is the cold combustion chambers and pistons do not burn the fuel cleanly until they get heated. . Mechanics opinion here can tell a lot by how the engine starts.

--check the revs with a digital phototach to see how accurate the tachs are or are not.

--Blowby check at dock and when out for the run. Opinion. There will be some even on new engines but the question is how much. Mechanic opinion.

--WOT test for rpm indication for whether propped correctly, over temperature, vibration, turbo boost if fitted.

--General electrical that the alternator works.

--Belts and any noise that is out of place

--Gearbox operation

--Raw water pump is not leaking gobs.

--General hose condition.

--THere are other things that individual mechanics will look at based on their knowledge of that engine/gearbox.

Borescope, compression testing and such inspections are usually not done. On many engines this is highly invasive and will result in the need to reset valves, fuel control racks and possibly monkeying injector seals which mean pull the head. You can ask but I think you will be refused.

A good mechanic can tell a lot by the startup characteristics

 

[IRENE]

I would prefer the engine(s) survey be accomplished by a subject matter expert that specializes in the particular engine being surveyed. I learned this with our last Volvo Penta, when we found “THE guy” after using several less-capable parts changers. Our guy looked at several engines and drives like ours per week, attended training annually, and knew shortcuts to save us time and $$.

When we bought our current boat, I contacted a large reputable Seattle marine diesel business that dealt in the three brands we have aboard. I was under self-imposed pressure to get the process done, and I didn’t put in the effort on the front end to find the right people. The technician quickly made it clear he was available for a long sea trial, and he did not want me in the engine room with him. He didn’t really provide any value - other than I was able to say we had an engine survey done. For example, he did not fill out the oil analysis forms correctly so the lab did not have the baseline data. The analysis were not useful. Basic inattention to detail. One boat buck, gone.

Fortunately, the boat was lightly used and the engines common and reliable. My surveyor provided far more value in the engine room than the “technician”, finding things the technician missed. He patiently explained his observations and fixed some things along the way.

So if I could do it again, I would have taken the time to find the right technician. My risk was low because of the condition and age of the boat, but the result was predictable.

 

[jleonard]

A lot of what needs to be done you can and should do yourself first in the slip. Especially the visual stuff.
If it passes your inspection then it's time to get an "expert".
That's MY opinion.

 

[Prospective]

Minimum for me on a diesel would be a professional tech, familiar with the specific engine performing survey. Would need to include visual inspection, fluid samples, examination of computer (if electronically controlled) and sea trial to ensure it was meeting operating specs for temps, pressures, and RPM. If that all came back clean and I had good maintenance records, I'd be comfortable.

 

[bgillroy]

At survey (pre-purchase)visual insp; oil analysis (E & T); Run test all metrics incl wot and back down test, etc.
An engine inspection and evaluation requires instruments is whole different testing protocol.

 

[koliver]

At survey (pre-purchase)visual insp; oil analysis (E & T); Run test all metrics incl wot and back down test, etc.
An engine inspection and evaluation requires instruments is whole different testing protocol.

What exactly would that protocol be? My insurer required me to get one, but couldn't provide any direction to the "Inspector".

 

[SteveK]

What exactly would that protocol be? My insurer required me to get one, but couldn't provide any direction to the "Inspector".

Can't answer the protocol part, but what reason did the insurer want the engine inspection? Are they insuring the engines?

 

[koliver]

Can't answer the protocol part, but what reason did the insurer want the engine inspection? Are they insuring the engines?

You bet they are.
I bet more insurance payouts are for engine "consequential damage" than any non-fire cause. Maybe an insurance guy will chime in and give the numbers.

Check your policy under "Hull and Mechanical"

 

[SteveK]

You bet they are.
I bet more insurance payouts are for engine "consequential damage" than any non-fire cause. Maybe an insurance guy will chime in and give the numbers.

Check your policy under "Hull and Mechanical"

OK, did some reading and what I find is that if the engines cause an incident otherwise not covered then it is covered. No mention of the engines being covered just the resulting damages.
Examples given is hoses cracking and letting in sea water sinking the boat. Usually a sinking due to a wear and tear item is not covered.
Is this your understanding?

 

[koliver]

OK, did some reading and what I find is that if the engines cause an incident otherwise not covered then it is covered. No mention of the engines being covered just the resulting damages.
Examples given is hoses cracking and letting in sea water sinking the boat. Usually a sinking due to a wear and tear item is not covered.
Is this your understanding?

Nope, depending of course on the wording of (and resulting premium cost) your policy.
In your example, if the boat is not a total loss, would see you covered for all except the cost of the failed hose. The sinking is "consequential damage". The hose failure is a maintenance item.

Dealing with coverage for "mechanicals", if you have some maintenance item fail, that causes an engine failure, the engine is covered as "consequential damage" to the maintenance item that isn't covered.

 

[SteveK]

Thanks Keith. will check into it more

 

[Prospective]

There are also yacht policies that cover mechanical failure of engines, generator, etc... Can imagine the insurance company would want an engine survey prior to coverage.

 

[Seevee]

Good info! Thanks

 

[Barrie]

I am about to get a pre-purchase survey and the surveyor said do an oil analysis. I said, the old owner did new oil change last fall just before winter layup. He said, there is enough junk left in the pan to warrant a good sample. I'm going.....hmmm is he right?
What think the TF minds?
Thanks

 

[CapeWhaler]

I see a lot of talk on here about oil sampling and let me be quick to say that, in general, I think it's a good idea - depending. My experience with it is in general aviation aircraft engines and I was religious about it. BUT - my feeling was, and my highly experienced A&P/IA (mechanic) agreed, that unless the oil had some hours on it and the sample was taken soon after engine operation, there wasn't a lot useful to be gleaned. The lab we used agreed and a couple of times when I sent samples with low hours, their feedback commented on the limited trend analysis generated.

Boat-wise, I probably know just enough about diesel engines to be dangerous (15 years maintaining my sailboat's Universal M18), and I'm still learning Serena's Westerbeke W100 (3 years now). The trawler had a recent clean hull survey (no actual engine survey) when I bought her, and I rolled the dice on foregoing one. When I sea-trialed with the broker he said let me take her out of the harbor and then she's yours to drive. I guess I surprised him by saying, "No, you drive awhile. I want to spend the first 30 mins in the engine room looking and listening with my inspection light, stethoscope, and IR thermometer." Which I did. I didn't see or hear anything that scared me, so I bought the boat; so far, so good. The engine had 3500 hours at the time.

So, IMO, it comes down to your comfort level with your chosen surveyor/mechanic and what you can glean about the boat maintenance history. As far as oil sampling, I'm generally 'fer' it, but I make sure the samples are taken when they'll mean something.
Joe

 

[TollerTrawler]

I am about to get a pre-purchase survey and the surveyor said do an oil analysis. I said, the old owner did new oil change last fall just before winter layup. He said, there is enough junk left in the pan to warrant a good sample. I'm going.....hmmm is he right?
What think the TF minds?
Thanks

Tried to buy a trawler through a broker who was rep'ing a purported "professional diesel mechanic" owner. Mechanical raised some questions, but the fluids testing had a shocking result. The $60 X 3 oil, trans, and coolant tests saved me a crapload of cash.

 

[Frosty]

Tried to buy a trawler ... Mechanical raised some questions, but the fluids testing had a shocking result. The $60 X 3 oil, trans, and coolant tests saved me a crapload of cash.

Can you elaborate a bit? What did you end up finding?

 

[Barrie]

To be clear, I am not questioning the importance of an oil analysis, but i am asking the validity of testing new oil that has been sitting all winter in a dirty sump. Is there enough old oil left during an oil change to show up in a test? BTW the oil in this engine is drained from the bottom not pumped out if that makes a difference.

 

[Frosty]

To be clear, I am not questioning the importance of an oil analysis, but i am asking the validity of testing new oil that has been sitting all winter in a dirty sump.

I would have the exact same question in your shoes. Seems doubtful to me (as an amateur).

 

[TollerTrawler]

Can you elaborate a bit? What did you end up finding?

Might be worth stating what is measured in a fluids test for those who haven't employed one before. For example, bellow is what is tested in the transmission fluid. Some of the same analysis elements are applied to the engine oil and coolant but specific elements are also added to each of those tests (too lengthy to list.)

Oil condition (viscosity)

Contamination
- silicon
- sodium
- potassium

Wear Metals
- PQ
- iron
- copper
- lead
- tin
- aluminum
- chromium
- molybdenum
- nickel
- titanium
- silver
- manganese
- vanadium

Additives
- calcium
- magnesium
- zinc
- phosphorus
- barium
- boron

Each is measured on a Nominal/Abnormal/Severe scale. Elevated levels can be indicative of issues in the engine, cooling system, or transmission. The report will make suggestions of specific issues, and recommend approaches on how to conclusively diagnose the problem (e.g.: disassemble the transmission.)

In the case of the engine we had tested, there was a rating higher than severe, that suggested a high likelihood of immanent failure. This, despite no signs of a problem in the engine inspection or sea trial.

I've been told that because of the sensitivity of the testing, even if fluids had been recently replaced, just running the engine up to operating temperature or conducting a sea trial before taking the samples (which is what we did) would still reveal potential issues.

 

[PM]

In my opinion, there are two types of engine survey. Both are good and always a good idea to do one or the other. It is your decision which direction you want to go and how much you want to spend.

I would say that if the engine shows over 4,000 or 5,000 hours you want a full fledged professional survey. Not so much for a boat selling for under about $50,000 but lots of very expensive boats have a single engine with 5,000 hours on it and the asking price can be close to a million. Get a full professional survey.

If the hours are fairly low, and the boat is selling for under $60,000 or $70,000 I would just do it myself. Ask for an oil analysis, or get one done, cheep and quick. Start it up, run it out check for leaks, noises and smoke. Does it achieve top RPM at WOT? Vibration or anything funny going on? What do the gauges say?

If you like what you see, buy it.

pete

 

[Ski in NC]

I do engine surveys as part of my business. I know certain engines very well based on experience, having rebuilt or repaired the same many times, etc. On those, I know the weak spots and know how to look for them, even when everything looks ok on the surface.

Other engines I do not claim to be an expert, so when discussing I clearly state my knowledge of that particular engine. Some go elsewhere, some hire me anyway.

Regarding oil samples, even if oil has been recently changed, about 10% of any contaminant still remains so you can still see a problem. Not so much wear metals (they can be all over the map) but contaminants like sea water, coolant or fuel.

Out of the hundreds of these I have done, maybe 25% could have skipped my service. The rest, I found some things that made the service worthwhile. Sometimes VERY worthwhile.

If the buyer is knowledgeable about boats and engines, 20min in the engine room accomplishes half of what I do. I would do the same things in the first 20min.

 

[Barrie]

Okay you have convinced me to get the fluids tested. As mentioned previously the owner changed oil last fall just before winter layup so if there are any gremlins left in the sump they will show up. The engine is a Cummins QSB 5.9 425 hp turbo with 1700 hrs and the Generator is a Westerbeke 7.6BTD with 750 hrs. My 20 minutes in the engine room reveals no issues. Very clean and lovingly cared for.
Folks you have all been very helpful on this subject. Many thanks
Barrie

 

[Ski in NC]

If oil was changed right before layup, and not run much after the change, not much mixing will occur between the old oil residual and the new oil. It does not take much running under load to mix things up (minutes, really), but some yards change it right before haulout with nothing more asked of the engine than maneuvering at idle.

Best to run the engine under load prior to taking the sample, but due to winter storage that is not often possible this time of year.

I'd still pull a sample, it is easy and cheap. But in this case it may not tell you much.

The QSB is a nice engine...

 

[Barrie]

Thanks Ski: for $30. it is a no brainer.
Barrie

 

[Shrew]

I prefer to have someone who is certified in that engine manufacturer survey the engine. Things you listed (seal leaks, exhaust color, temps, oil analysis) that can be done by any diesel mechanic.

However, it's the other little things. Recall's, known issues, that I'm more concerned about. Yanmar had a series of 'soft blocks' on their 6 cyclinders engines for a certain number of years, but only on certain serial number ranges. They also had an issue with valves dropping on a certain model and range of years. (On that one you could tell by the type/color of a certain part). I'd like to know those little 'gotcha's.

 

[SteveK]

Shrew, Is there such a thing as factory trained boat engine mechanics, like with cars.
If there is not then whoever has the best experience with an engine. But how do you determine that.
I was told the head on an engine had to come off. So I had a look and torqued it, tightened the valve cover. Then I replaced the damper which was the real problem.

I think people should hope to get someone that knows more than they do. I have only found one boat mechanic that I learned a lot from, and he may be retired any day.