Engine Quit

[Seevee]

Had a strange thing happen last night.

Started the boat, like I have many times before, and often let it idle for a bit. This time went back into the house to help the Admiral get ready and that took an hour.... she couldn't decide what to wear.

When I got back to the boat, the engine had quit. I had all the electronics on, so I started the genny to add a little charge to the battery and a bit later started the engine. Ran fine. Nothing seemed wrong.

Ran it for a short run, about 15 min. Shut down for a few hours, started up again for another 15 min run and everything was fine.

Just wondering what caused it to quit.

Usually it's a fuel problem, but apparently not, as it ran fine again and the genny ran without a hitch. Spec of water? Don't know.

Thoughts?

[Ski in NC]

Check racor bowl for any sign of water. If none, turn fuel valve off and pop top off of racor and check fuel level inside. If a couple/few inches down from the top, you may have low fuel or air intrusion issue. Pump primer button and see if it is firm.

Any recent work on fuel system or filter replacement or fuel tank filling?

Was key still on and alarm buzzing? Annoyed neighbor may have shut it down.

[alormaria]

Ennui?

[HopCar]

Originally Posted by alormaria

Ennui?

That's funny. I had to look it up, but it is funny.

[Xsbank]

Why let it sit running? Pointless and ultimately damaging.

[sunchaser]

S, I'm with XS.

Can't tell you why your engine quit, but I might suggest that letting a cold engine idle for an hour is not recommended. Possibly fatal I've heard some engine experts say. Why do it?

[Xsbank]

I also agree with Ski, a neighbour turned it off! Noise, smoke, more smoke and noise. For over an hour? Yuk

[Seevee]

Originally Posted by sunchaser

S, I'm with XS.

Can't tell you why your engine quit, but I might suggest that letting a cold engine idle for an hour is not recommended. Possibly fatal I've heard some engine experts say. Why do it?

Sun,

Would you and X respond as to why you say that? I've had boats idle for several minutes up to an hour or so many many times without an issue. Perhaps to provide power for something or just waiting to depart. What is the problem?

[Seevee]

Originally Posted by Ski in NC

Check racor bowl for any sign of water. If none, turn fuel valve off and pop top off of racor and check fuel level inside. If a couple/few inches down from the top, you may have low fuel or air intrusion issue. Pump primer button and see if it is firm.

Any recent work on fuel system or filter replacement or fuel tank filling?

Was key still on and alarm buzzing? Annoyed neighbor may have shut it down.

Ski,

Good info, and I'll do that. A glance didn't show much, but I'll go into the detail you post.

And, no, a neighbor did not turn it off. They couldn't even hear it from their place, and if outside, they'd just tell me. Hasn't happened in the last 45 years. No key and alarm on.

And no recent work.

[rwidman]

I once (and only once) started my engine and then walked away from the boat. We were trying to figure out how to move a disabled boat to the place where it could be hauled for a hurricane.

We were on the other dock and as I walked back to my boat, I saw the bilge pump discharge. Not a good thing. I ran to my boat and lifted up the floor hatch.

Well, at some point, the cover on the seawater strainer had cracked and failed and the engine was spewing sea water all over the compartment.

I shut it down of course, but I still had to move my boat to get it hauled so a bunch of duck tape made a temporary repair.

Moral of the story - leaving your engine running unattended for more than a few minutes is not a good idea.

[RBack]

Originally Posted by Seevee

Sun,

Would you and X respond as to why you say that? I've had boats idle for several minutes up to an hour or so many many times without an issue. Perhaps to provide power for something or just waiting to depart. What is the problem?

Well I'm neither of them. But I'll throw my self into the topic anyhow.
The main reason for not letting a recently started (cold) engine idle too much, is that it requires a lot of extra time for it to reach proper working temperature. During that prolonged period of running below working temperature, it's prone to extra wear and tear.
So normally - at least in theory - the life of an engine is shortened when used/treated this way.
With diesels there is also some risk och cylinder glazing if they work unloaded over extended periods of time. However, I guess glazing sensitivity differs between various engines (makes, models).

Idling (for charging batteries or other purposes) after proper warm up is not as harmful.

[sunchaser]

S

A long idle after a cold start does not usually raise oil temperature enough to burn off volatiles and water. An oil temperature of 175+ is desirable for cooking off these "nasties" based upon my reading, courses and experience.

Just as gensets can suffer from long periods of no load, propulsion engines can too. Ski has opined in the past on underloaded gensets, I'll defer to him on this no load question. Also an exchange with Tony Athen's may further answer your query. I do know what he has said in the past regarding long idle periods.

[chriscritchett]

Obviously it shut down because everyone on TF was aghast that he left it running.

[BruceK]

Originally Posted by chriscritchett

Obviously it shut down because everyone on TF was aghast that he left it running.

And because WesK once had a cracked seawater strainer.

[kthoennes]

I had an idling engine shut down just last week too, which was very unusual for my otherwise smoothly running, purring engines. Turns out it was a loose screw to the wiring on the ignition switch and with just the right vibration, engine neatly shut down, no cough or anything.

(I'm not sure I get all this discussion about "blowing out volatiles." Some of the guys in my marina are under that impression too and you see it in other boating forums, this idea that once in a while you have to motor out of the yacht basin and blast the throttles like NASA rockets to "blow out the engines." Clear the crud. Blast out the carbon, whatever. Flogging combustion engines within an inch of their lives to "clear the pipes" doesn't make sense to me. And think of all the boaters in Florida waiting for bridges to open, or New York waiting for locks to open. Or heck all the engines idling for hours and hours on the Cross Bronx Expressway or I-5 every day, all those cars would quickly crud up and die. I waited 40 minutes for the Old Lyme Railroad bridge to open on the Connecticut River last time because the bridge operator kept changing the time estimate for the next train. Wasn't dead idle, only holding position, but pretty close. But then what do I know, I'm no boat mechanic and I don't play one on TV.)

[chriscritchett]

You have to wonder. All the reactions are no doubt well intended and probably factual to a degree, but I'm guessing with the number of hours actually accumulated on our toy-boat engines, we could probably all do the WORST possible thing to them most of the time, and we'd never notice how much shorter the service life was. Letting them sit around waiting to be used is likely the biggest offense.

But I'm just guessing. And sometimes I let my engine idle for way too long and sometimes I push it up on plane before it's quite up to temp. Time will tell.

[sunchaser]

Originally Posted by kthoennes

I had an idling engine shut down just last week too, which was very unusual for my otherwise smoothly running, purring engines. Turns out it was a loose screw to the wiring on the ignition switch and with just the right vibration, engine neatly shut down, no cough or anything.

(I'm not sure I get all this discussion about "blowing out volatiles." Some of the guys in my marina are under that impression too and you see it in other boating forums, this idea that once in a while you have to motor out of the yacht basin and blast the throttles like NASA rockets to "blow out the engines." Clear the crud. Blast out the carbon, whatever. Flogging combustion engines within an inch of their lives to "clear the pipes" doesn't make sense to me. And think of all the boaters in Florida waiting for bridges to open, or New York waiting for locks to open. Or heck all the engines idling for hours and hours on the Cross Bronx Expressway or I-5 every day, all those cars would quickly crud up and die. I waited 40 minutes for the Old Lyme Railroad bridge to open on the Connecticut River last time because the bridge operator kept changing the time estimate for the next train. Wasn't dead idle, only holding position, but pretty close. But then what do I know, I'm no boat mechanic and I don't play one on TV.)

KT

My comments about having oil temperature hot enough to burn off moisture and volatiles has nothing to do with running engines to clear the pipes as you suggest. Also, I tried to focus my comments on a cold start idle as opposed to idling a hot engine for long periods as many of us have done.

But, like you, what do I know? Which is why I recommended S contact the experts.

BTW, what are your thoughts as to why the engine in question stopped? In less than 500 words.

[psneeld]

While I dont idle for the sake of idling, I also wouldnt leave the boat idling for an hour by itself as something could go wrong and an early catch may save some coin (though more than a few minutes is just your risk tolerance and mine is up around 15 minutes).

As to idling for an hour from a cold start, I too havec ead enough expert opinions to say not to do it, but occasionally and how the engine is run most of the time is all in the mix.

Sometimes we pull out of marinas and get caught by a bridge not opening on time and wind uo idling for longer periods than I want too, but then again, the engine is usually bumped in and out of gear....it that really matters.

[CDreamer]

I have a 2015 Jeep with a diesel. The manual says to put a heavy load on it periodically. I'm a pretty sedate driver so I have consciously do it on a weekly basis.

[Xsbank]

Lots of information on this, even on this site. The proper way to warm up a diesel is to start it and drive away. Diesels are so efficient that they will probably never reach proper operating temperature at an idle, they will smoke, waste fuel and probably the result is glazing the cylinders. The jerk-ignition engines most of us have are most efficient at a certain rpm, probably very close to the torque peak where they are running loaded and burning fuel most efficiently. To see this effect most dramatically, watch the Sunday startup at Roche Harbour after the Grand Banks Rendezvous when up to 120 GBs all light up at the same time. The sheen in the water and the smoke is literally breathtaking. Once they all move off and start to warm up, the smoke vanishes.

Nobody is suggesting that you run your engine hard while cold, we are saying that warming up with a load is best. If you must idle for long periods of time and you wish to get your temperatures, put it in gear.

Then again, do what you want or do, what your buddies on the dock do or do what your grandfather did. This is perilously close to anchor-type and oil type discussions for voodoo and nonsense.