Check for water in cylinder

[LukeS]

Hi all, following a heat exchanger failure on a VP D2-40 I am concerned that I may have had some coolant get into the cylinders. I found water in the exhaust manifold when I took the heat exchanger off - and in at least 2 of the exhaust ports on the engine block. I’m worried that if I try and start it up with water in a cylinder it could cause no end of damage with the high pressure. Or can I simply operate the injector stop lever so that it won’t fire up and see if it will crank over under starter motor. I don’t know whether that is powerful enough to do damage or whether it would “just” hydraulically lock if there was water in a cylinder.

Any suggestions on how to check and clear out if necessary? I was thinking of removing the injectors and seeing if I could look inside each cylinder using an endoscope camera. Not sure if that would work or if there are better ways?
Thanks
Luke

 

[rogerthebodger]

Remove the injectors and then turn the engine over and this will shoot any water out of the injector holes

 

[LukeS]

Remove the injectors and then turn the engine over and this will shoot any water out of the injector holes

Thanks. Two follow on questions if I may
1) To the extent it doesn’t get every last drop out I assume it shouldn’t stop it firing up and any remaining water will evaporate off more or less instantly?
2) I’ve never removed injectors before but hear they can be a b*gger to get out. Any tips on that (or a recommendation for a cheap puller that fits a VP D2)?

Thanks
Luke

 

[rogerthebodger]

Yes injectors can be a bugger to get out. There are injector removal tools but have never used one.

The one thing to consider is to replace the copper washers for new ones when the injectors are replaced to get a good seal.

Have you determined if the is a leak allowing water to get into the cylinder.

I have pressure tested each cylinder to see if there are any leaks from the cylinder to find out if there are any leaks into or out of the cylinder

U Tube has some videos that show how to do this that will test several types of cylinder leakage from rings, valves and the cylinder head

 

[LukeS]

Yes - the leak was the classic corrosion in the heat exchanger (not a cheap fix in itself) that enabled coolant to escape in to the exhaust manifold. Most of it went out the exhaust but, due to corrosion in the exhaust elbow that was almost blocking the pipe, enough remained in the manifold when the engine was stopped to spill over in to the exhaust ports. When I took the heat exchanger off the forward two ports had some water in and the aft two were dry. Not sure if that is a function of the way the boat/engine sits in the water - or because in the aft ports the water had got into the cylinder through open exhaust valves. Only one way to be sure - take the injectors out. Thanks for your help - and yes I will use new copper washers. I might take the opportunity to get the injectors checked (after 14 years and 1400 hours I don’t think they have ever been serviced).

 

[William_H]

I would suggest that a test with starter motor turning over the engine would prove if there is water in the cylinders. Yes it will hydraulic lock but starter motor should just stall on load. If it will turn over of course water should be ejected from exhaust valve. ol'will

 

[vyv_cox]

I would suggest that a test with starter motor turning over the engine would prove if there is water in the cylinders. Yes it will hydraulic lock but starter motor should just stall on load. If it will turn over of course water should be ejected from exhaust valve. ol'will

Better to bar it over by hand. A hydraulic lock even driven by the starter motor can cause expensive damage.

 

[B27]

If the engine has a decompressor, then turn it over decompressed. By hand at first, then starter motor.

If it doesn't then removing the injectors is one way, but this involves messing with the HP lines and new seals and may not be easy.
An old mechanic told me the thing to do is wedge the exhaust valves open a crack by forcing shims under the rockers.
Never done this myself, never needed to.
So I can't assure you it's right for all engines.

 

[RAI]

If the engine has a decompressor, then turn it over decompressed. By hand at first, then starter motor.

If it doesn't then removing the injectors is one way, but this involves messing with the HP lines and new seals and may not be easy.
An old mechanic told me the thing to do is wedge the exhaust valves open a crack by forcing shims under the rockers.
Never done this myself, never needed to.
So I can't assure you it's right for all engines.

Or over tighten the rockers on the exhaust valves.

 

[LukeS]

Thanks all. No decompression levers on a VP D2-40 - and I’m nervous about “wedging shims” - so think I will go down the hand crank route and if I can’t hand crack it I will assume the worst and pull the injectors.

 

[rogerthebodger]

I had an issue with one of my engines and count not hand crank so had to have the engine rebuilt completely.

Even after removing the injectors

Mine was a Perkins 4 236

 

[B27]

Thanks all. No decompression levers on a VP D2-40 - and I’m nervous about “wedging shims” - so think I will go down the hand crank route and if I can’t hand crack it I will assume the worst and pull the injectors.

I can understand that.

Personally I feel that when you've had water in an engine, it's good to get it running ASAP.
Whether it's a dunked outboard or a trail bike that's been in a stream.

I don't know how hard it is to remove injectors on your engine, or what 'one thing leads to another' tasks will be generated?

I was just passing on some seriously secondhand 'knowledge' really!
Good Luck with it,

 

[vyv_cox]

Thanks all. No decompression levers on a VP D2-40 - and I’m nervous about “wedging shims” - so think I will go down the hand crank route and if I can’t hand crack it I will assume the worst and pull the injectors.

No need to be concerned about 'wedging shims'. A screwdriver will do perfectly well. Assuming that barring over by hand meets terminal resistance from hydraulic locking, simply lever the exhaust valve of the firing cylinder open with a suitable tool and expel the water into the manifold. Repeat a few revolutions and then try the starter motor.

 

[DownWest]

Not familiar with the model, but does it have preheaters? If so, easier to remove than the injectors.d

 

[Boater Sam]

Wind it backwards for two complete revolutions, that will let the water out if there is any in there.
Then wind it forwards two revs before starting it, providing you can wind it forward by hand.
No need to remove any injectors or heaters etc.

 

[LukeS]

A thought. Would I have the same effect from removing the glow plugs and cranking the engine over to expel water, rather than the injectors? It feels as though that might be a much more straightforward operation?

 

[david_bagshaw]

Be careful with removing heater plugs, they have a nasty habit of snapping..

If it was my problem,
check oil level, if higher than normal remove oil from sump & replace
pull stop
turn engine over with a spanner on the crankshaft. That would determine if there was too much water in the cylinders. if so, get a pal to lightly press down on the appropriate exhaust valve to expel most of the water from that cylinder, while turning crankshaft
then fill the tappet clearance with appropriate feeler gauge, and add a 5 thou one to keep the exhaust valve open.
do same with each cyl.
turn engine round with spanner.
when certain no undue force is required, .
bump round with starter.
then crank with starter.
introduce teaspoon of oil to cyl via inlet tract.
turn over by hand then bump, then crank.

go for a no throttle start.

 

[LukeS]

Thanks all for your input. In the end I pulled the injectors (and am having them serviced). Cranked on the starter motor and fortunately no water came spurting out - so think I got lucky and the water was only in the exhaust port. Now just a matter of putting it all back together!