What a engine survey does not tell you

Hi,

You got that in one.

The paint is always a good way to tell what has and hasn't been taken apart and re assembled so are the nuts and bolts once you are familiar with an engine and what it should look like.

The problem wirth written records is that they are easy to fudge, I have seen this on a mage yacht where the engineering team got well written up for how well and thoroughaly they did the maitenance.

The truth came out when trying initially to cure a constant alarm when manouevring.

Then I was told the Chief had done a full mega test himself in 2 hours, it didn't take long after this to really start picking holes in the story he was spinning.

Took a while but managed to get him and his old ex navy friend the 2nd engineer replaced with a couple ofd decent guys.

In these cases you site 'dbltime', how extensive were the engines surveyed? Could the problems that arose be connected to an incomplete survey, or is it just very difficult to tell the condition of some engines?

Why would that be specific to Cats?

Could that scoring have occured in such a short period (baring proper oil and coolant) ? Or was it not picked up on at survey? Do they compression check diesel engines everytime at engine survey? Wouldn't that scoring have shown up?

My concern with oil analysis is that it might not be a good indicator of engine condition if the oil had been recently changed in the engines?

Do you have any knowledge / cases that involve gas engines? Are there major differences in their survey procedures to your knowledge?

I'm looking at a vessel that has twin 454 Crusader gas engines that have totally inaccurate hour meters, and may have been unused for a significant time. Is a simple compression test going to give me a good indication as to whether to proceed forward with addition engine testing and the remainder of the survey?

Hi,

Compression test, Bore Scope, Oil sample and look in the valve covers for deposits, white stuff etc.

A single oil sample on its own will only tell you what is the condition of the oil currently, it is a tool tat works best when a few are done/known about and a trend can be developed.

Any engine with a wet exhaust that is left to sit can easily end up with rust on the liners and the engine valves that are open.

It is not something specific to CATS, I have seen it on MTU's as well.

Hi,

Are you saying the cooler failing on one engine was the initial cause of the problems?

It does not say that in any of your previous posts in this thread from what I can see.

The failures I have seen came mostly from rust and gummed piston rings which do a pretty good job of chewing up the bores and pistons.

Cat did have aftercooler failures on those motors. However, CAT stepped up to the plate and covered them under warranty (even if they were out of warranty) well over a decade ago and I haven't seen any issues with those motors since with the updated aftercoolers at all.

Your facts are wrong.
Cat recommends cleaning the heat exchangers/aftercoolers every 1000 hours, not by years. Man requires it every 2 years, not Cat. Having scored cylinder walls, and the other motor come apart sounds to me like someone ran them WOT for the entire day or something crazy. I've never heard of CAT issues like that. It sounds like a Yanmar issue which was common on the 440hp model, and all 39' Eastbay's of those years have Yanmars not CATS. Most of the 48's had CATS. Maybe you should get your facts straight.

Volvo TAMD74P's
Injectors are supposed to be checked every 2,000 hours (no frequency specified)
Valves are supposed to be adjusted every 1,000 hours (no time limit specified. )

http://www.kb-kbh.dk/shipslib/motorer/volvo/volvo_penta_tamd63a-72j-a_instruction_book.pdf SEE PAGES 36-40. Maybe you should Google the info you claim to possess on the manufacturers website before spouting a bunch of BS. All of the 39' Eastbays have Yanmar's as far as I can see, not CATS.

If it started black smoking 3 hours of running at cruise, the fuel filters got dirty/clogged and could have water in them and the Captain running it like that destroyed the injectors. Any good Captain would've seen the smoke trail behind them, slowed down, shut one down, and pulled/checked a filter before detroying all of the injectors. I do agree that a sitting boat creates a lot of problems as does a lack of maintanence, but your facts are all wrong.

YEP.
Lack of use is what kills most any mechanical equipment in the marine environment.
The engine surveyor can only report what he saw on a given day. He is not going to investigate any service history.
Oil samples are the same.
Oil sample history during the engines life and documented service will always shine thru.

I would add one other thing. When purchasing a used boat, if you can't ascertain for sure what service has been performed, then it probably would be a good idea to look at all recommended service up to it's age and hours and then at the very least check to see if you can tell it was performed or otherwise perform it now.

I would also say that most owners who have been diligent on maintenance have records or at the least can refer you to the service people they've been using. While it's not always the case, in general sloppy records in that regard are very consistent with sloppy attention to maintenance. It's the old adage of cars that if what you can see has been poorly maintained then likely the mechanical aspects have as well. But most people who are diligent about maintenance also can provide a history.

The 39' Eastbay never came with C12's or C15's, the 48' Eastbay did.

You've got me on the cat book with the years. It does have the year thing on the C12's and C15's they must've added that over the last couple of years, but on most of those items it means inspect them every 2 or 3 years, clean or adjust if needed. I managed/maintained a yacht with C15's 2007, and the book definately DID NOT have years on the service interval, only fuel usage or hours for maintanence schedules back in 2006 when this boat was built their service manual that came with the boat would not have years in it for valve last, H/E's etc. Chances of Heat exchangers needing cleaning at 350 hrs and 6 years old is very rare. The valve lash at 250hrs is important and should be done but I don't think it would kill a motor with 335hrs by not doing it, and I don't know how you'd inspect a fuel injector on an electronic diesel without pulling it out and having it tested. Possibly hook the computer to it and have the computer test them with a cutout test.

Hi,

As far as I a aware CAT have always had a calendar based maximum in addition to hours run/fuel burned in their service manuals procedures.

Sometimes it was not displayed as prominently as other times.

I am curious to know how a cut out test will tell me the atomisation pattern of my electronic injectors.

Can you please explain this for me and the rest of the curious?

If 1 cylinder drops less RPM's than others during the cut out test, it will generally tell the computer that that injector is not firing properly or atomizing properly. If every cylinder drops 200 rpms, and cylinder #7 only drops 100 rpm's during the cutout, it will generally mean their is an issue in that cylinder (which could be other things such as piston rings, a valve, etc). The only proper way to test atomization fully is to pull them and put them on a machine and have them flow tested. That being said, I have never, ever had a CAT dealer pull injectors to simply test them on a good running electronic diesel with lower hours (under 2000 hours)......whether it be 2 years old, 5 years old, 10 years old. I've seen them test them with the computer......maybe technically it's called something else such as a load/balance test?