Hydrolocked engine?

[Chmielar]

Hello,

I was watching the “Speed with Guy Martin” today and I think I may found a possible solution to the problem with my boat's engine. This was the part when he was hydroplaning motorbike on the lake in Snowdonia and after crashing he managed to hydrolock his engine.

On my Carter 30 I have Vetus M3.09 engine. Last season, on two occasions, after sailing in rough weather the engine was very difficult to start. The starter motor was engaging the wheel but it looked like the engine was kicking back after about half a rev. I was wondering, if during the sailing when the boat was heavily pitching and rolling, a diesel could have been leaking from faulty injector into the cylinder to the point that it became partially hydrolocked. Is this even possible (enough volume of fuel in pigtails)? Has anybody experienced a similar problem? I double checked and the propshaft was disengaged during the starting.

Please advise where else to look? I do have sometimes a problem with starter motor solenoid but it usually works after a few turns of ignition key. This gives a characteristic click and it is a different behaviour to the one described above. Any ideas or suggestions would be very welcomed.

Regards,
Pawel

 

[Bilgediver]

Hello,

I was watching the “Speed with Guy Martin” today and I think I may found a possible solution to the problem with my boat's engine. This was the part when he was hydroplaning motorbike on the lake in Snowdonia and after crashing he managed to hydrolock his engine.

On my Carter 30 I have Vetus M3.09 engine. Last season, on two occasions, after sailing in rough weather the engine was very difficult to start. The starter motor was engaging the wheel but it looked like the engine was kicking back after about half a rev. I was wondering, if during the sailing when the boat was heavily pitching and rolling, a diesel could have been leaking from faulty injector into the cylinder to the point that it became partially hydrolocked. Is this even possible (enough volume of fuel in pigtails)? Has anybody experienced a similar problem? I double checked and the propshaft was disengaged during the starting.

Please advise where else to look? I do have sometimes a problem with starter motor solenoid but it usually works after a few turns of ignition key. This gives a characteristic click and it is a different behaviour to the one described above. Any ideas or suggestions would be very welcomed.

Regards,
Pawel

It sounds like you might have a problem with the layout of your exhaust system which under certain conditions is allowing water into the cylinders via exhaust valves.

The water may be coming in from the transom outlet or it could be leakage past the water punp and finding its way to the injection point on the exhaust bend.

Do you have a vented loop in the line to the engine from the water pump fitted well above the engine. If you do then this would prevent water finding its way in through this route when the engine is stopped and so indicate water might be entering the exhaust at the stern.

Vetus have diagrams showing how to prevent this by fitting a swan neck at the stern and a suitable sized water trap close to the engine.

I doubt your problem is due to fuel leakage at injectors however it is not beyond possibility that there is water leakage at the injector pockets if these are separate components expanded into the head like on some other engines.

Your electrical problem with the starter could be due to the soloniod contacts becoming burnt. This is not unusual and it is a relatively easy job to fit a new solonoid. These are available from Auto parts companies such as Partco or Dingbro. Most modern solonoids are disposable and not easily opened up for cleaning the internal contacts.

 

[William_H]

Surely witha hydralock be it fuel or water it will remain locked until the fluid is released (decompression) or by removing an injector. With a hydralock the starter can not turn the engine over through a cycle where the fluid escapes through the exhaust valve.
My guess is that the bounce back is from high compression of air and is a symptom of poor starter power. ie from bad battery or starter motor. You should have become familiar with a good engine start from the sound and speed of cranking. Any change or slowing of the start would be reason to consider battery failure. If you have dual battery ssytem then try jump start from both batteries at once. If this improvees the crank speed then your starter battery is dying. assuming it should be or is well charged. good luck olewill

 

[SAMYL]

If it is hydrolocked for whatever reason do not attempt to force it or damage will ensue.
Try turning the engine backwards and you may be able to free it that way. Do not attempt to start it unless it can be turned freely by hand ( ie spanner on flywheel nut or whatever)

 

[john_morris_uk]

We experienced this problem from time to time and I discovered that it was down to a fault in the exhaust system layout. I don't believe for one moment that its a problem with an injector. An injector problem would also manifest itself when the engine was running. The forces and pressures are much more severe then than the roughest passage you will have made.

The symptoms you describe (especially as associated with starting after rough water sailing) sound to me exactly like our problem. What I strongly suspect is occurring is that water retained in the exhaust system (hopefully in a proper water trap?) is being 'sloshed' by the more extreme motion of the boat back into the engine and down past an exhaust valve and hydraulic locking the engine.

I used to have to take a glow plug out and spin the engine over. The amount of dirty oily water that came out was always (depressingly) impressive.

I regret to report that the problem led to the rebuild of the engine soon after we bought the boat.

I've rebuilt the exhaust system now and fitted a high rise exhaust water injection manifold but in the roughest weather and most extreme conditions the problem has recurred once or twice. (Much cursing from me about salt water in my newly rebuilt engine!). However as I've cleared it immediately and run the engine until it's properly hot no harm seems to have been done from the couple of occasions so far.

My advice wound be to check the design and heights of everything relative to engine and waterline carefully against the Vetus recommendations. You might also consider checking that the baffles in your exhaust water trap are still there. (They might have melted through internally and out of sight if you've ever run the engine without sea water cooling accidentally for any length of time?)

 

[Talulah]

When we replaced the engine 7 years ago the exhaust layout was slightly changed. Instead of the silencer box being directly behind the engine it was relocated to one side. With the boat healed the wrong way the exhaust hose was almost horizantal between the engine and the silencer box so if the engine was turned off whilst healed on the one side any water in the exhaust pipe could have flowed back into the first cylinder. This happened on several occasions making the engine virtually impossible to start. Susbsequently I had a high riser made (about 300mm) by Halyard Marine. This meant the exhaust hose was no longer horizantal when healed and the problem has not repeated itself since.
At the time if the initial installation the dealer fitted a Yanmar high riser mixing elbow which gives about 4 extra inches of lift. This clearly was not enough.

 

[Heckler]

When we replaced the engine 7 years ago the exhaust layout was slightly changed. Instead of the silencer box being directly behind the engine it was relocated to one side. With the boat healed the wrong way the exhaust hose was almost horizantal between the engine and the silencer box so if the engine was turned off whilst healed on the one side any water in the exhaust pipe could have flowed back into the first cylinder. This happened on several occasions making the engine virtually impossible to start. Susbsequently I had a high riser made (about 300mm) by Halyard Marine. This meant the exhaust hose was no longer horizantal when healed and the problem has not repeated itself since.
At the time if the initial installation the dealer fitted a Yanmar high riser mixing elbow which gives about 4 extra inches of lift. This clearly was not enough.

Heeled?

 

[Talulah]

Heeled?

;-)

 

[bikedaft]

we have had this twice - in retrospect, engine should have had a high riser fitted but insufficient space

easy to clear from engine - decompress and turn over

fitted a seacock on exhaust outlet thru stern, closed when at sea or boat left on mooring, and also ran a drain hose from vetus water lock to an accessible part of bilge to drain exhaust completely (when engine off)

of course you may have a few other tings causing your symptoms eg dud batteries/wiring/starter etc?

 

[john_morris_uk]

we have had this twice - in retrospect, engine should have had a high riser fitted but insufficient space

easy to clear from engine - decompress and turn over

fitted a seacock on exhaust outlet thru stern, closed when at sea or boat left on mooring, and also ran a drain hose from vetus water lock to an accessible part of bilge to drain exhaust completely (when engine off)

of course you may have a few other tings causing your symptoms eg dud batteries/wiring/starter etc?

Thank you for that idea. I might have a look and see if we can do the same. I might get it to drain into a container as the exhaust water is oily and smelly.

(We too have fitted a sea-cock on the exhaust to close in rough weather.)

 

[bikedaft]

Thank you for that idea. I might have a look and see if we can do the same. I might get it to drain into a container as the exhaust water is oily and smelly.

(We too have fitted a sea-cock on the exhaust to close in rough weather.)

ran garden hose pipe from vetus water lock to bilge inspection hatch in cabin sole. you could collect it in eg a 2l milk bottle or whatever plumbing 15mm inline valve on end hose on bit of copper pipe was what i had lying around 5 years ago. not rusted yet...

 

[Chmielar]

Thank you all for your comments and advice! On my exhaust installation waterlock is mounted on a side of the boat and I can see how in rough weather the water can make its way back into the engine. Also, I need to review electrical installation including the starter. I have a dedicated new battery for engine starting. It is marked with CCA 650A but the engine seem to be much happier staring on 2 batteries anyway. I’m considering replacement with CCA750A designed for starting.

I will not be able to operate a seacock on exhaust and I’m thinking about gooseneck instead. This is because the access is extremely awkward for installation - never mind closing it when engine is stooped.

I will also consider the manifold raiser but, taking into account special constraints, it is unlikely I will be able to fit it. I like the idea of draining the waterlock and perhaps with gooseneck on the outlet the problem won’t reoccur. BTW: has anybody considered fitting the valve on exhaust hose between engine and the waterlock?

I’m comfortable with most of engine jobs but if anybody can recommend a good mechanic in the Clyde please do. We are moving the boat further north this year (Oban area) and we will have 1 year old to look after on board. My wife wants a comfort of being able to relay on the engine and I need somebody to blame when something goes wrong.

Thanks again for your advice. It is very valuable and I will follow up on your suggestions.

Regards,
Pawel

 

[Tranona]

Don't forget to put an anti syphon valve in the raw water circuit. For a gooseneck the simplest way to do it is to have a loop of exhaust hose immediately before the outlet, and going as high as possible under the deck. Expect you are short of space in that part of the boat and a moulded one from Vetus might be easier to install.

A 650CCA battery should be more than enough to start the engine so maybe you need to check all the connections and cables and have the starter tested before you buy a new battery.

 

[MM5AHO]

I had similar symptoms, and all started after installation of a hot water system (calorifier) which caused me to change the exhaust layout. It had previously had a vetus swan-neck style water trap, lying along the centreline of the boat, just above the propshaft. I had moved off centre and slightly across the beam instead of along the line of the keel.
Several waterlocks at sea, sorted within minutes, but disconcerting at the time.
Final solution was to increase capacity of waterlock, and to change to the cylindrical type, which has more flexibility of positioning. Its now still slightly off centreline, but I can put the toerail way under water (!) and not get a waterlock.

 

[lw395]

There are two separate issues here.
One is water pumped into the exhaust from the seawater cooling circuit.
The other is water entering the exhaust from the sea while sailing. Particularly in a following sea. This can slap the transom and enter the exhaust with pressure and momentum to go uphill to the engine.

The first needs either the mixing elbow to be above waterline by a margin, or a loop and syphon break in the seawater to mixing elbow hose.
Plus a water lock of adequate volume.
The second needs either a loop of exhaust high up inside the transom, a 'swan neck', a seacock in the exhaust or a flap over the outlet on the transom.

Even with these things, people have been caught out after a long trip under sail.
Perhaps starting the engine every 12 hours to blow the exhaust clear of excess water is a good idea in some conditions?