Engine survey question

[Don L]

So if you are considering a 1980s boat with diesel engines that have around 3,000 hours and you seatrail the boat, running the engines hard for 10 minutes and later getting an oil analysis showing no problems, plus you checked the engine over pretty good yourself after having researched the engine to know the common problems;

Do you feel you still need an engine survey?

 

[AquaAura]

Running it hard for 10 minutes doesn't seem long enough to me. I just had an engine survey done and we ran the boat longer than that. The surveyor also temp checked all the shaft packings and we ran it from 1600- 2600 which is max and he wrote information for every RPM in 200 increments to make sure we continued to make speed and check pressures and temp.

In my case I have worked on many engines so I would be comfortable in your situation as long as the price is right but for me my $1200 engine survey caught a bad transmission oil cooler with an transmission oil sample which showed water in the oil that didn't show up on the dipstick. That being caught saved me about $1000 I would have to later pay if not more cause had it not been caught I may have ruined a transmission.

 

[Don L]

Running it hard for 10 minutes doesn't seem long enough to me. I just had an engine survey done and we ran the boat longer than that.

Interesting. On here a few months ago people went crazy about a buyer requiring a WOT run of 5-10 minutes.

 

[AquaAura]

If by running hard you mean max RPM for 10 minutes then that seems fine. We ran at 2200 which is max continuous for much longer than 10 and at 2600 for maybe around 10. Wasn't sure what you meant by "hard" as that is subjective.

The boat we are looking at is a 1986 and it has an all new or reconditioned engine room in 2016 with 130hrs and we still found the issue with the cooler so just use caution in accepting something because it "should" be good.

 

[SteveK]

So if you are considering a 1980s boat with diesel engines that have around 3,000 hours and you seatrail the boat, running the engines hard for 10 minutes and later getting an oil analysis showing no problems, plus you checked the engine over pretty good yourself after having researched the engine to know the common problems;

Do you feel you still need an engine survey?

Don,
If your pockets are deep then you do not need an engine survey since you can afford whatever comes up.
If you cannot afford to rebuild an engine, then a survey may help in prevention of a purchase that will lead down that road sooner than is reasonable.

 

[AquaAura]

Just because you can afford the fix that doesn't mean you shouldn't survey. You buy a boat for 100k thinking all is good now you have to pay 30k for a new engine. Had you found that on a survey then maybe you would pay 70k

 

[PM]

It kind of depends on the engine and previous use. A Ford Lehman, Cummins, John Deere or the like in a trawler is barely broken in at 3,000 hours. The same number of hours in a sport fisherman making 600 hp is about done for.

pete

 

[sunchaser]

Marine engine surveys usually fail to pick up the areas that cause the vast majority of issues, the hang ons. Sure see if the boat is over propped (not the end of the world) but water pumps, alternators, bad wet exhaust geometry, HXers, after coolers, PTOs, belts and hoses are the ever lurking issues.

One look inside an ER will reveal a lot before ever starting the engines. Then a cold start, soot on the transom shaft vibration come into play. How about peripherals not part of the engine or drive train? A lazy uninformed mechanical surveyor will do an engine run up checking temperatures but still get it wrong. It being, the subtle things that shut us down while the engines purr away.

 

[ranger58sb]

So if you are considering a 1980s boat with diesel engines that have around 3,000 hours and you seatrail the boat, running the engines hard for 10 minutes and later getting an oil analysis showing no problems, plus you checked the engine over pretty good yourself after having researched the engine to know the common problems;

Do you feel you still need an engine survey?

Another it depends. And also depends on what you mean by hard.

If I could run it at WOT for 5 minutes or less, the engines make rated RPM, and if the gauges and IR heat sensors don't show an inordinate temp rise during that... and if the engines appear clean and ship shape in advance and afterwards... and if the oil sample return is good... and if I couldn't find a specialist in that particular engine brand/model...

Then I might forego a mechanical (engine) survey. Maybe.

But surveys are cheap, in the grand scheme of things, and if the rest of the boat has already rung my chimes... an extra few $$$ for an engine survey would likely bring me more peace of mind AND it might turn up something that could affect final purchase price.

And even if you can't negotiate price some more, it could give you an idea about what immediate work (if any) might be necessary or at least recommended once the boat is yours.

The oil sample thing is a bit of a juggling act. Often, you'd take samples after sea trial... and get results man-yana sometime... but sea trial is often also the same time when you'd maybe want an engine surveyor... and then oil samples...

I assume a competent surveyor, expert in the brand/model in question. Not some jack-leg off the street who just learned to spell "diesel."

-Chris

 

[O C Diver]

Interesting. On here a few months ago people went crazy about a buyer requiring a WOT run of 5-10 minutes.

That wouldn't work on my boat, the propeller is over pitched. I would have no qualms about doing it in neutral, but it won't go over about 1,900 in gear.

For me, if the oil has been recently changed, I would analyze engine oil, transmission oil, and coolant after a very long seatrial. Each can warn you of potential problems.

Ted

 

[jungpeter]

Don,
If your pockets are deep then you do not need an engine survey since you can afford whatever comes up.
If you cannot afford to rebuild an engine, then a survey may help in prevention of a purchase that will lead down that road sooner than is reasonable.

Hi Don L (the original poster). SteveK is right on the money. Have the engine(s) surveyed by a competent diesel mechanic prior to purchase. This is money well spent, and a mere fraction of the money you'll spend should you discover engine problems after purchase that weren't revealed without this survey. Don't step over a dollar to pick up a dime by cheaping-out the purchase process. Good engine surveys are priceless.

Regards,

Pete

 

[ancora]

We bought our twin engine boat 23 years ago without an engine survey as they had only 340 hours on them. Now with 2040 hours they're still ticking.

 

[Don L]

So if you are considering a 1980s boat with diesel engines that have around 3,000 hours and you seatrail the boat, running the engines hard for 10 minutes and later getting an oil analysis showing no problems, plus you checked the engine over pretty good yourself after having researched the engine to know the common problems;

Do you feel you still need an engine survey?

running hard = WOT

this all you know so there are no "depends"

 

[ranger58sb]

running hard = WOT

this all you know so there are no "depends"

Fair enough. As I said above.

I don't think I'd usually need more than 5 minutes at WOT. If the temps are staying stable, good. If they're only increasing a bit... not uncommon for temps to rise a bit until the thermostats for fully open and coolant is flowing properly. Some of that assumes I know in advance what the correct operating range is, what's outside of acceptable temperature range.

If the temps are still rising after about 5 mins, there's likely something that needs attention. Could be several possibilities, or some combination of a couple.

But at that point, I'd get heavy into "re-evaluate" mode: back down RPM and think about it a bit.

That'd be where it's useful to have an engine specialist (that brand/model) already on board for better "thinking about it." I probably wouldn't know enough abut the foibles of a given engine to do great analysis.

And I'm fairly conservative, recognizing there's a boatload of stuff I don't know about. I might have a better clue about an engine brand/model I've owned before, but I'm only about 1/4" deep across the board on diesels in general.

-Chris

 

[mvweebles]

My "just depends" is whether I am confident I can find a knowledgeable and experienced mechanic. If it's a pretty basic diesel such as a Ford Lehman or Perkins, I might be inclined to waive-off the expense of a surveyor if I can't find a decent mechanic. I've seen mechanics from large shops (or "Factory Certified") who are pretty useless.

That said, it would be much easier to negotiate a survey credit for a defect or concern with a mechanic's report than a buyer's say-so. Also helpful to know what it would take to baseline the engine - pump/impellor, hoses, clamps, etc. So while I can see the reasoning not to have a mechanic survey, I think it's probably money well-spent, if for nothing other than the negotiating power (or peace of mind if nothing found).

Peter

 

[Comodave]

We had a Cummins mechanic do the “engine survey “ on our current boat. He was absolutely useless. Cummins finally wrote off the $1,500 charges because the mechanic didn’t really do a legitimate survey. So it all depends on the individual mechanic.

 

[AquaAura]

It all comes down to what you are paying at what your level of knowledge and comfort are. We had a fantastic Cummins mechanic look at our and as I said if he hadn't been there I may have only done engine oil samples but he is saving us now that we know the transmission oil sample was bad so the survey paid for itself. Do whatever you are comfortable with.

 

[BruceK]

So if you are considering a 1980s boat with diesel engines that have around 3,000 hours and you seatrail the boat, running the engines hard for 10 minutes and later getting an oil analysis showing no problems, plus you checked the engine over pretty good yourself after having researched the engine to know the common problems;

Do you feel you still need an engine survey?

With your extensive knowledge depicted on TF, no, you would not.

 

[Don L]

With your extensive knowledge depicted on TF, no, you would not.

Get such help here

 

[rslifkin]

Depending on what information I was able to gather from the engines and how much I know about the specific engines in question would determine whether I'd feel an engine survey is worthwhile. I'd be comfortable with doing my own engine survey on gas engines, but I'd be less likely to get into doing a compression test on a diesel and would likely bring in a professional for a few things after I did the basic checks.

 

[sunchaser]

No wrenches are normally allowed during an engine survey unless a pre existing issue is known. Thus a diesel compression test is not going to happen.

 

[AquaAura]

I did a compression test when I boat my current boat and the buyer did one when he bought it from me. Compression test is a normal thing nothing excessively intrusive.

 

[C lectric]

No owner I know of would allow a compression test. Most mechanics would dissuade you. They are highly invasive involving pulling injectors, upsetting valve adjustments and requiring specialized tools and the knowledge to use them effectively.

If like mine the engine will require a full timing and injector reset. and MANY hours of work. Not just an hour.

These ARE NOT like gas engines.

The only diesels that would somewhat readily allow a compression test are those with GLow plugs. Not many of those around anymore.

If you demanded a compression test I bet you will be told to take a hike unless you wish to have another few thousand dollars added to your inspection bill.

A GOOD mechanic can get a lot of info from how the engines COLD start, the smoke level at start and how quickly the engines settle to an idle.

 

[Comodave]

I have never seen a survey with diesel engines that included a compression test or any wrenching.

 

[AquaAura]

Sorry I should clarify that it was done on a gas engine and I didn't do a compression on the diesel we are buying

 

[Comodave]

I assumed you were referring to a gas engine and that is why I specified diesel engines.

 

[Delta Riverat]

A cold start in 1-2 seconds is a good enough diesel compression test.

 

[mvweebles]

Any thoughts on a "tissue test" for rudimentary blow by evaluation? Open oil fill cap and see if there's much crankcase pressure indicating worn rings? I've heard of it but no idea if it's legit or myth. Thoughts?

Peter

 

[AquaAura]

As far as I know it's legit and we checked it on the one I'm buying and also shined a flashlight to check for smoke out of the fill cap as well.

 

[Patrick4002]

it depends on the documentation provided by the previous owner and the first impression of the motors. For example our last boat, we got a first look around, i always carry my laser temp meter, it was december, the motors look like just out of shop, the engine room was clean, and all the maintenance was done (with invoice) by the engine manufacture and makers of the boat(carterpillar in my case) the engines where cold (december) they started with a 2 sec (i did not count) cranking, run like a smood sewing machine. so the first impression was fine only a 2400h on the engine and a 3400h on the genset.
i got a seatrail in the harbour (i was 6bf) and we had to travel 2 days to get there. so i let the boat lift out the water to inspect the bottom (i also had a extra man to look at the boat and installations, to get a second opinion, the prise was good so i did not do a survey. without the service history i would had done a motor survey