What can stop my engine?

[HopCar]

I have a single engine boat with a twenty plus year old engine. It has low hours for that old an engine and I haven't replaced many of the accessories over the years. Now I'm worried that things can fail and leave me stranded.
What should I replace before it fails and gets me stuck?

Starter - relatively new
Mechanical Fuel Pump - original
Raw Water Pump - Original seals, new impellers yearly.
Coolant Pump - Original
Heat Exchanger - Several years old - looks good inside
Alternator - original I think.
Turbo Charger - relatively new

Can you guys think of anything else to worry about?
The engine is a Cummins 6BT5.9M diesel.

 

[Marin]

It doesn't seem to me that you need to replace anything but you might want to carry some spares (if you don't already) so you can replace some of the easier items if they fail.

While everyone's idea of sufficient spares is different, from your list this is what we carry for our engines--- two new fuel lift pumps, one raw water pump, several new impellers and gaskets for the raw water pumps, and one FL120 coolant pump.

We also have spare belts pre-threaded onto the engine ready for use (an FL120 anomaly), a couple of spare thermostats, a full set of hoses--- raw water and coolant--- for each engine, and some fuel hoses.

 

[jeffnick]

One More Time Around: Spare Parts for Your Boat

 

[FF]

Bad fuel (or NO fuel) is usually considered the stopper for a mid life engine.

The old concept of an emergency GRAVITY tank might work as insurance.

 

[DavidM]

Cummins has a quirk of using a fuel start solenoid rather than a more typical fuel stop solenoid. So when the solenoid fails the engine won't run. Although you could wire the run/stop lever in the run position if the solenoid fails, carrying a spare might be good insurance.

And of course it goes without saying- spares are only as good as the tools and skills that go along with them.

David

 

[RickB]

Now I'm worried that things can fail and leave me stranded.

If things are going so well that you need to find something to worry about, consider the concept of "infant mortality." When you replace an item, it is just as likely to fail as an old worn out unit.

Can you guys think of anything else to worry about?

Almost everything if that is what makes boating enjoyable.

 

[Alfton]

Do not forget to carry spare engine oil in case of a large oil leak

 

[Aquabelle]

BoatDiesel's Cummins guru, Tony Athens, recommends overhauling/checking "everything that spins" on the front of a 6BTA engine....see that site for detail. You will also find a strong consensus that redundant raw water, coolant temp and oil pressure alarms are also considered good protection.

 

[HopCar]

Thanks Rick! That's just what I needed to hear.

When the boat was new, I bought what spares I thought I could change my self. These included a spare starter motor. A couple of years ago the starter died and I replaced it with the new spare. The new one didn't work either!

I have a new spare fuel pump but now I'm wondering if I should replace the spare. It's twenty years old.

David, thanks for mentioning the solenoid. I wasn't aware of that.

What started all this is that a couple of weeks ago I had the belt break. I had a spare belt but the belt tensioner had gone bad so I was towed in for the first time in my life. The belt on this engine is tensioned by a spring loaded pulley. My fault, I knew it was going bad but delayed changing it. Now I want to get ahead of the curve. Having spare parts is great. Not needing them is better.

FF, fuel is another issue I'm dealing with right now. I can't run on my port tank. I know how to deal with that. I like the gravity tank idea.

 

[RickB]

I replaced it with the new spare. The new one didn't work either!

If it sat on the boat for 30+ years without being inspected or serviced then it probably failed many years ago. Those things are not packed for long term storage like military machinery parts that will probably be good as new when the pyramids are gone. Use 'em or lose 'em.

I have a new spare fuel pump but now I'm wondering if I should replace the spare. It's twenty years old.

See above. Don't replace it though, send it to an injection shop for testing and calibration. When you get it back, either install it or vacuum pack it for proper long term storage. If you install it, have the old one tested and store it properly. Those things are "rotable" spares.

I knew it was going bad but delayed changing it.

Ah, the rest of the story ... most machinery will tell you it needs attention. Do what it tells you and you won't be worrying like this.

 

[Forkliftt]

Wear items

HC, I always try to think of mechanical components as an assembly of "wear items". For instance, a lot of starters have bushings that the armature and starter drive spin inside of. If your engine starts frequently, say like a UPS truck, then those bushings will surely not last as long as the same starter in a boat application that starts and then runs for possibly several hours. BUT, if your batteries are low or you have a voltage drop in your positive or negative cables on your boat, then you will see increased amperage draw from your starter (Ohm's Law). These higher amps will probably cause burned tips inside your starter solenoid, possible arcing at the brushes and the heat can actually damage the field coils and allow them to short against the starter case. Pisser. Probably not the case usually but possible. So there are many causes of parts failures. You had a failure on your tensioner that caused a belt failure. I think tensioners are a great advancement. One of my pet peaves is to follow up behind another mechanic that has tightened a V belt WAY too tight. He solved the problem. Squealing alternator belt (only right after start up, thats when the big load occurs), his solution is to tighten that SOB as tight as possible. Problem is- two months down the road the alternator bearings fail. Why? Excessive belt load. Usually the original problem is a very worn alternator pulley. By the time a new belt has slipped and worn to match the profile of the old pulley, the belt is glazed and no longer is soft enough to not slip on the pulley. I personally think that once a boat gets to be the age that ours are, any failure needs to be really understood- and look at that part or component as a piece of a "system". Understand the system and you will probably understand the failure. ...Personally, I keep spare coolant lines, trans oil cooler and an engine oil cooler as spares on the boat along with a spare RW impeller. I yield the floor!

 

[bshanafelt]

How you use your 5.9 makes a difference. If you run WOT all the time the motor will not live as long than if you cruise at 1500 rpm all day. I suspect accessory and marinization parts will also suffer from extreme use.

Some say the best comparison test of a marine motor is total fuel consumption over the life of the engine, which indicates HP being used from the motor typically. If you ask 370hp from this same block and use the motor at or near the max, you will certainly have fewer engine hours before needing major work. Instead, if you normally use 40hp from a de-rated version of the same block, you should get many more engine hours before needing the rebuild. Of course, all things being equal - you gotta use and take care of (regular service) any motor or it will rust to death.


on the fuel solenoid, it is possible to buy one that works the 'other' way i.e. Fuel Stop
Electrical :: Coils :: Cummins 3904630 Solenoid MDCREC6350973 - Mara Industrial Supply: Parts Done Fast

this does requires a small electrical adjustment.


On the raw water pump, if it is an M71, those seals will fail - look for any green staining below the shaft - or worse raw water piling up on the front port motor mount.

I carry an entire spare pump assembly - includes the gear, plus the gasket needed to mate against the engine. A quick and easy change when tied up.
Just put a new impeller in every year, which will solve that wear issue - check the wear plate too.

Also, watch your wet exhaust elbow - these have a calandar attached to them as well as engine hours - most say 10 years is pushing it.

Regular by the book maint. is spelled out in the manual.


otherwise, a pretty sturdy diesel for a boat application -

 

[Castrol]

Have not seen fuel filters mentioned this is one of the most frequent reason of failure, maybe a spare starter and alternator.
Best of luck

 

[millennium]

For me having a twin I will let some parts go until failure, ex. starter. Unless it's a really bad day with multiple failures I can get the boat to service and parts.

I do keep a supply of filters and fluids, some hoses, impellers, belts.

 

[HopCar]

I knew I shouldn't have admitted it was my mistake. Rick, you're enjoying this way too much.

I do carry a good set of spares but I would rather avoid using them. Some of them are now so old that I worry they may be no good if I do need them. Time to throw money at it. Install new parts and buy new spares.

Thanks for all the good advise.

 

[RickB]

I knew I shouldn't have admitted it was my mistake. Rick, you're enjoying this way too much.

I don't get any pleasure from it and I hope others learn something from it.

I do carry a good set of spares but I would rather avoid using them. Some of them are now so old that I worry they may be no good if I do need them. Time to throw money at it. Install new parts and buy new spares.

Whoa, wait a minute ... the fuel pump should be sent to a shop and tested. It might still be OK and if so, install it and send the current one in for overhaul and keep that as a spare. Rotate your spares, don't just wait until you are afraid to use them then throw them away and buy new ones again.

 

[HopCar]

Rick, you might as well have some fun. I am.
The fuel pump I'm talking about is the little mechanical lift pump, not the injector pump. Do you think I should have the injector pump checked out? How long do they go without problems?

 

[RickB]

Rick, you might as well have some fun. I am.
The fuel pump I'm talking about is the little mechanical lift pump, not the injector pump.

Ah so ... well, in that case dump it, the diaphragm is probably dried out anyway.

Do you think I should have the injector pump checked out? How long do they go without problems?

Until they quit. It will probably go forever. I suspect the governor will start to give problems like hunting and you might have low power eventually as the plungers wear and leak but it's unlikely you will have a sudden and total failure.

 

[FF]

Folks with twin engines that hope to canabilize the pair to keep one in operation should have aboard NEW gaskets for all the contemplated swops.

Sure a sheet of gasket material can be made to work, but cutting and fitting in a rolly dead in the water boat may be too much of a Bonus job .

 

[OFB]

Ah, the rest of the story ... most machinery will tell you it needs attention. Do what it tells you and you won't be worrying like this.

Thats my take as well. But as an oldguy its the new electronics , the addition of lots of electrical that seem to be letting me down these days. Stuff just stops working no warning it just stops. So far its usualy just some safety switch for neutral protection with a bad connection or a china made BW solinoid that dont disconect leaving the starter to just carry on ( battery disconect switch is cool ). I call em soft parts even when I hammer my finger putting them in. The base iron engine has always given me a sign and got me home.

I can fix alot of stuff with a good selection of tools and epoxy. Parts can be tough to stock on board.

Fun stuff.

 

[sunchaser]

Here is list for my engine shutdowns. Please note , not ever bad fuel, which some claim as #1

• Engine alarm (genset) activated due to cooling water shut off.
• Stop solenoid BO
• Raw water leak in after cooler
• Leaking RW pump
• Leaking coolant reservoir
• Leak in exhaust elbow
• Low battery

Above is in about 3800 total engine hours of use for a 2003 vessel.

 

[Brooksie]

I too have and 40yo downeast boat and engine. In the 35 years i have run this boat, I have broken down 3 times.
1) transmission oil cooler: bypassed it, drained water from trans, refilled limped to port.
2) drive plate: towed to port
3) " " " " "

Experience tells me:
Eng & trans oil coolers can be bypassed but you must drain or pump the water out & have enough new oil to refill and make it home.
Drive plates can fail w/o warning and you are dead in the water. Get one with a get home feature like PIY sells. A spare is NG as it can't be changed without tools unlikely to be onboard.

I would mention also, you can't do much about a seized freshwater circulator pump and even if you convert to salt water cooling, as I once did 70mi offshore, you can't run anything else that was on the same belt.

 

[El Sea]

"What can stop my engine?"

Add water to the fuel and see what happens.

Spare Racors on board?

 

[Edistoart]

Hopcar

Your spare starter motor that didn't work is one reason that some experienced mechanics and long haul cruiser's recommend not stocking spares but buying spare parts and installing them, keeping the removed parts for spares after cleaning them and refurbishing them if necessary.

1. Then you know that you can change them out properly and have the necessary tools and materials.

2. You know that the part is correct for your machinery and that it works properly.

3. Why not run your engine on new parts? Let the old parts sit around as spares!

 

[RT Firefly]

Greetings,
Move this to OTDE.....

 

[CPseudonym]

Greetings,
Move this to OTDE.....

Rather than move a perfectly good thread and topic to OTDE I decided to split out the completely off topic content and locate it there.

http://www.trawlerforum.com/forums/s7/chinese-quality-issues-7818.html

Enjoy your new thread gents.

 

[Blue Heron]

Hmm I can't access that Chinese goodness. How do I get access to ODTE?

 

[CPseudonym]

OTDE is an opt-in sub-forum within the Off Topic section.

Go to the Off Topic forum, click on OTDE and follow the prompts. Unfortunately I do not know how it works specifically.

 

[Blue Heron]

Got it. Thanks!

 

[RT Firefly]

Greetings,
Thanks Mr. CP. If we're all diligent we can limit the those....ahem...discussions to their own "special" area.
Mayday, mayday....ALL OTDE'ers....we have a newbie. Let's be gentle