Running dry for hours. .. what damage could have been done?

[sailorboy1]

Originally Posted by SecondBase

Can you help me understand your reasoning? Wouldn't finding metal fragments of chromed cast iron wouldn't give insight into condition of the piston rings? Are you saying no baseline makes the oil analysis useless?

An overheated engine to the point of that showing in an oil analysis would most likely already be known to have an issue just by running it.

[ramblinrod]

Originally Posted by Rachinwokingham

This is a strange tale of a boat that apparently started itself. Repeatedly.

We recently bought a 20 year old Oyster 55 in Corfu and found a marine engineer with a good reputation to service our M90 Perkins engine and generator. We left him the keys and returned to the UK for a week only to get an alert from the marina three days later. 'Your boat is running and smoke is coming out of the back but no water is running from the boat exhaust'. WTF? We called the engineer who swore it was impossible. He had been working on the boat the day before but swears he had left everything switched off (including the seawater inlet stop cock).
He quickly came on board to find the engine running, the starter motor repeatedly firing, the starter motor wiring and plastic casing above it a smoking melted mess and the boat full of black smoke. We were very lucky that the boat hadn't caught fire. According to our neighbours the engine had been running for at least five hours and the winch above the engine was hot.
We are insured but our problem is this. Apart from finding out what on earth went on, the engineers who swear it is an electrical problem are telling us they are '99.9% sure' the engine is OK. They did a compression test which was 'fine' and they say the coolant never boiled over, proof that the engine didn't overheat. We will be covered by insurance for the rebuild of the starter motor, rewiring work and new starter motor batteries. But what damage might have been done internally to our engine that might not show up on a compression test and cannot be seen by a visual inspection?

Thanks for any suggestions!

It sounds to me like the motor was not actually running, but was being constantly "turned over" by the starter (likely due to wiring malfunction).

I had this happen a couple years ago when a "less than handy" slip neighbour called me over to his boat in a panic that the diesel was "running on".

I placed a rag over the breather intake but it just kept "running".

As I scratched my head, he was about to place his hand on the starter to look deeper into the engine compartment, I yelled "STOP!"

The engine was not running at all. The starter was constantly running turning over the engine.

For your case, if there was no water coming out of the exhaust, that is a very good thing indeed. It means that the seawater intake valve was closed, and the engine cylinders were not flooded with water which may have cause hydrolock and severe damage.

You will require new starter wiring to replace that damaged. I recommend replacing the seawater pump impeller and starter with new and keeping original, assuming it will still turn over the engine, as a known fitting and working used spare. (The marina service person should cover the other, but may not cover the starter replacement if it currently seems to function perfectly. If it got so hot the paint or labels burned, they should.

[seacottage]

I have a Perkins Sabre M92. The engine started by itself and ran dry for several hours in 2015. The Marina in the Bahamas managed to kill the engine whilst still running. The engine coolant was completely drained from the engine. The starter motor was bunt out and totally ruined. I flew out to the boat and replaced the stater motor with a spare one I had on board. I fixed 2 small leaks at the exhaust muffler and the thermostat, replaced the engine oil and the coolant. There was no water in the engine oil. I pressed the starter button and she started immediately. She's been running for 2 years now. She always starts immediately, loses no coolant and no water in the oil. She does not smoke, has not lost any power and runs like a dream. Only a Perkins engine is capable of surviving this kind of disaster as was confirmed by my mechanic.
Starter motors can give electrical problems and start the engine by themselves. This is not an irregular occurrence. Make sure you disconnect/kill your engine batteries when not on the boat.

[a64pilot]

Originally Posted by boatpoker

Never seen a diesel that could get up to operating temperature let alone overheat at idle with no load. If you have a plastic muffler that might be an issue. You will certainly need a new impeller but I'd also be concerned about the bearings and shaft in the raw water pump

I agree, an issue with Diesels is that at low RPM and no load, they just won't develop enough heat to get up to operating temps and begin to "stack" that is oil and unburned fuel accumulate.
Let a truck or Bulldozer idle for a few hours then race the engine, it will smoke like a train as the oil and fuel begins to burn off.
Many engine designs cool the oil with the engine coolant, often these are in fact oil heaters as under little load they just won't get the oil hot.

If it didn't boil over the coolant, I maintain it didn't overheat, but the exhaust system is likely ruined, hoses, muffler etc.

The raw water pump may be done for too if it had no water flow through it. A quick look at the impeller will verify if it had water flow.

[Jim Cate]

Umm... Guys, the OP says that the sea water inlet valve was OFF. This has obvious connotations re Kenomac's points.

Jim

[JPA Cate]

Originally Posted by Rachinwokingham

This is a strange tale of a boat that apparently started itself. Repeatedly.

We recently bought a 20 year old Oyster 55 in Corfu and found a marine engineer with a good reputation to service our M90 Perkins engine and generator. We left him the keys and returned to the UK for a week only to get an alert from the marina three days later. 'Your boat is running and smoke is coming out of the back but no water is running from the boat exhaust'. WTF? We called the engineer who swore it was impossible. He had been working on the boat the day before but swears he had left everything switched off (including the seawater inlet stop cock).

He quickly came on board to find the engine running, the starter motor repeatedly firing, the starter motor wiring and plastic casing above it a smoking melted mess and the boat full of black smoke. We were very lucky that the boat hadn't caught fire. According to our neighbours the engine had been running for at least five hours and the winch above the engine was hot.


We are insured but our problem is this. Apart from finding out what on earth went on, the engineers who swear it is an electrical problem are telling us they are '99.9% sure' the engine is OK. They did a compression test which was 'fine' and they say the coolant never boiled over, proof that the engine didn't overheat. We will be covered by insurance for the rebuild of the starter motor, rewiring work and new starter motor batteries. But what damage might have been done internally to our engine that might not show up on a compression test and cannot be seen by a visual inspection?

Thanks for any suggestions!

Hi, Rach,

For the purposes of your insurance, yes, have your guy change the oil, and check the old oil for metal traces. Cheap insurance. If there are metal shavings, you will probably want to really watch your oil consumption, and for blue smoke that is more than normal, possibly have the tear down done on the engine. So you need to prepare the insurance company, but you want to know, for your own good, too.

Any part of the whole system that could have been damaged by hot exhaust gases should also be checked. All wiring that shows heat damage should be replaced.

Have your guy check the coolant impeller, and buy a new one, if you don't already carry a spare. If you have a spare, have him put it in and still buy another one.

Have him take the injectors to the injector shop, and have them tested, and have the guys there put it in writing if they think the engine event has caused the need to replace them...

Follow up on everything else the experienced guys have to suggest here. The better the documentation you can present to your insurance company, the better they will be able to help you.

Finally, have some sort of sign or something made up for whoever works on your boat to turn off all the breakers when they leave. (or all but the automatic bilge pump, if you leave that one on when you're away)

Ann

[SecondBase]

Originally Posted by sailorboy1

An overheated engine to the point of that showing in an oil analysis would most likely already be known to have an issue just by running it.

Thanks SailorBoy. So should OP run the engine and put an IR temp reader at each cylinder housing and look for differences?

[SailingFan]

You guys are making me decide to make a sign up for my little Yanmar! I am going to have to take a look for the best place to install a kill switch for the starter on it now.

Not like I don't have anything else to do with my boat at the moment... HA HA HA!!

What I was meaning in my prior post about a design defect potential is that sooner or later (and probably already) some schlub is going to be in there working on an alternator install or perhaps checking for something behind a transmission mount, and the engine is going to fire up and maim or kill him or her. The aircraft incident comes to mind as well, and I have to imagine that some product liability will come to play, at least it will in the US (I agree, we sue too much, but there are literally millions of hungry lawyers here, I would bet, who would love to take on such a case). It is simply a matter of poor design of systems, and it leaves the operator with "you should know to hang a sign/read a sign/be a better mechanical genious even if the vessel is new to you" as a disclaimer. Forget all the folks in the adjacent slips whose boats go up in your fire.

I would hope that someone has come up with a better mousetrap than this by now, but apparently not? So in the switch must go...

[Fence Man]

Makes me glad to have an old 2 stroke outboard on my boat. Most of the time, it won't start with help, let alone get the job done by it's self.

[Kenomac]

Originally Posted by Jim Cate

Umm... Guys, the OP says that the sea water inlet valve was OFF. This has obvious connotations re Kenomac's points.

Jim

I can't understand why a supposedly competent diesel technician would leave the batteries connected to the starter and close the sea water supply valve, then leave the boat. The next person coming along would most likely start it up and go... not knowing the water was shut, or something like what happened happens.

[Rachinwokingham]

First of all, a big thank you to everyone who posted. Sorry it has taken me a while to get back to the forum. Boat cleaning all day! Now I am settling back and reading through all the posts. The forum really is amazing for questions like this. Thanks guys!
Where to start? Just to clarify, the engineer said that the main switch for the batteries was well and truly switched off. We only have his word for it though, as we were in the UK when it happened so only have witness statements to work out what went on. The sea water inlet was definitely switched off but the engineers say they think the stop cock was leaky enough to have allowed some water to circulate. We checked the sea cock and there is no water coming through when it is closed but maybe the pump pulling managed to get some through. The engine was idling in the marina and the starter motor was continuously running. This has burt out the starter motor and all associated wiring.

Interesting to read the comments about how engines self starting due to a short is not that uncommon. It is also heartening to hear that a Perkins engine should not overheat even without a running sea water circulation when idling. The engineer has rebuilt the water pump and says that the impeller was OK. He has changed it and put new bearings in nonetheless.
Also interesting that some Oysters have a water separator in them. Ours doesn't unfortunately, as it is a bit older than Kenomac''s boat.

Now we are just trying to figure out what we need to have checked as part of the insurance claim. We want to make sure the engine is reliable enough for some long distance travelling and want to minimise the number of surprises.

Thanks again for all the comments.

[Rachinwokingham]

The engineers were in the middle of a job and due to return to the boat to work. According to them they did switch the batteries off. Everyone we have spoken to has said this makes it totally unprecedented for a short to cause the motor to start.

[Rachinwokingham]

Some great suggestions there Anne, many thanks!

[Kenomac]

You need to find a new mechanic IMHO. There's absolutely no way for an engine to start when the battery shut off lever is in the "off" position. Personally... I wouldn't put in an insurance claim for a worn out and shorted starter motor, the insuance company is going to make you first pay a deductable or deny the claim as being a mechanical/service/maintenance issue. I can't imagine a payout for something as described. Sure they'd pay out for a fire, but they're not going to buy you a new starter motor.

[Rachinwokingham]

Originally Posted by seacottage

I have a Perkins Sabre M92. The engine started by itself and ran dry for several hours in 2015. The Marina in the Bahamas managed to kill the engine whilst still running. The engine coolant was completely drained from the engine. The starter motor was bunt out and totally ruined. I flew out to the boat and replaced the stater motor with a spare one I had on board. I fixed 2 small leaks at the exhaust muffler and the thermostat, replaced the engine oil and the coolant. There was no water in the engine oil. I pressed the starter button and she started immediately. She's been running for 2 years now. She always starts immediately, loses no coolant and no water in the oil. She does not smoke, has not lost any power and runs like a dream. Only a Perkins engine is capable of surviving this kind of disaster as was confirmed by my mechanic.
Starter motors can give electrical problems and start the engine by themselves. This is not an irregular occurrence. Make sure you disconnect/kill your engine batteries when not on the boat.

Good to know.... fingers crossed that we have a similar happy ending!