Caterpillar panic, help please!

[Rohorn]

Hi people,
Son just started new job in Gulf skipper brand new dive support boat with twin Caterpillar 3126B -1647858 turbo diesels. Went out for first longish run day before yesterday, allowed 20 minutes cooldown time before switching off. Next day, tried to start, horrible knocking noises, both, one wouldn't start at all. No smoke from exhaust, checked racor glass bowls, so not water.
Tried to get help from local agent but everything shut down for a week for the Hadj!! Panic. Will it be a public beheading?
From my experience with small Yanmars on the family cat, I would guess air in fuel, sucked in on cooldown. Suggested trying to find the air bleed screw.
He says that apparently these motors automatically bleed air out (past a check valve?) when the manual primer pump is operated till pressure feels "hard", which he has done, so there is no need to break into the system.
Also local Filipino "engineer" suggested tweaking thermostats by removing "o"-ring seals to ensure motors wouldn't overheat. Temperature is 20 ambient at the moment, I wouldn't want to do that on new engines without approval of agents. Motors have slightly less than 25 hours. Running temperature is supposed to be about 200 degrees, which I have to assume is fahrenheit because otherwise......
Any of you guys with sizeable power boats have any experience or advice to offer? Is there a Caterpillar equivalent of the "Yanmarhelp.com" site?.
Would very much appreciate help to cool down son.
Cheers....R

 

[Benbow]

I can imagine the cold sweat..

my best suggestion would be to ask your question here:

http://groups-beta.google.com/group/rec.boats

I haven't looked at it for ages, so no guarantees, but it is US dominated with discussion of bi engnes likke tghese. Worth a try.

if you are not registered with google groups you need to register.

Don't use your real email address for this but it must work long enough to complete the registration.

I can post it for you if it would help

 

[Shantyman]

Wouldn't make any mods without makers agreement or they can slide out from the warranty. This would not please the boss.

There is a very good U.S.A. web forum called Boatdiesel.com which is well worth a look at.
You have to pay about 25 U.S. dollars to join as an active member but this can be done on line of course and If you get the help you need it's well worth the cost.

You can probably browsw the site free and maybe pick up some good links.

Best of luck,

Shantyman.

 

[Rohorn]

Hi again...the panic seems to be over. The fault was discovered. It seems some work was going on yesterday tightening up the stern glands. Access to these means squeezing past the engines. In so doing the main fuel tap, new and still easy to turn, got knocked shut.
As ever, think of the last thing that was done in the area, and investigate! A clue also was that when he removed a Racor bowl to check for water there was a vacuum inside, instead of some fuel coming out.
I called Caterpillar marine dept in Hamburg and got the same strong advice about tampering with the thermostats...don't do anything without the main agents approval or the warranty could be voided. Wait till they are back after the Hadj!
One interesting info about service intervals came out in conversation with the Caterpillar engineer. Perfectly logical, but not seen at the level of small boat motors. Servicing once a year, or after so many hundred hours doesn't mean very much. What is really important is the amount of fuel used in a given time. From this one can see how hard an engine has been working. The motor we were discussing uses 90 litres per hour flat out. Much less when cruising. The fuel used in a given number of hours shows a clear picture of the work done, and hence a better estimate of service needs.
Thanks very much for your responses...cheers....R

 

[Shantyman]

Further to previous post I have downloaded a few bits which may be relevant from the Cat forum on Boatdiesel.com

It runs to 4 pages so I will pm it to you.

Rgds.

Shantyman

 

[tyce]

yep, as soon as i read your first post i knew the problem,
i have sailed with these cat engines on ships where the are used as emerg gennys, when the fuel filters choke they make a sound like they have thrown a piston, change filter runs like new again, the fact the fuel cock was starving the fuel rail has had exactly the same effect.
good reliable engines tho.