Hydrolocked after winter storage
 

I took my boat in for winter storage as usual last year and it was running absolutely fine. This spring when they put it in the water it was hydrolocked and couldn't be repaired without replacing the engine for $7,000+... lots of rust in the cylinders, etc. My question is, how could this happen? Is it possible no one is at fault here or should I suspect that the marina was negligent in some way either in the storage or spring preparation process? Or even, could I have caused this somehow and how can I avoid this happening again!?


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Only way you can get that kind of corrosion in the cylinders is if the engine was not properly winterized - IE fogged. The fogging process coats the piston walls with oil to prevent aforementioned corrosion. Furthermore it sounds like the boat was stored in a place with a high amount of humidity or where condensation was forming which is not good either. Sometimes that can be a result of large temperature swings in a short period of time where cold metal tends to attract moisture similar to a cold glass a water on a hot day.

No matter how the moisture got in there, proper preparation of the engine prior to storage should have prevented that kind of damage from being done. I'd be having a serious discussion with whoever did the winterization that's for sure!

Your marina screwed up. If it was truly hydro-locked, it was more than just moisture. What is the engine? I am thinking they did not drain the block or risers and the water froze over winter. So the question remains if it is just the engine or the risers as well.

Good luck, but I would be fighting them on this especially if they stored and had possession all winter!

Agreed. The person that performed the winterization is responsible.

I have my doubts it's hydrolocked though as that would suggest at least one of the cylinders are filled with fluid...in this case water....which doesn't compress.

Have you pulled the spark plugs to see if the engine is in fact hydrolocked?

I'm more willing to say the piston rings have rusted themselves to the cylinder walls due to improper fogging in which case I'd be considering a couple tablespoons of Marvel Mystery Oil in each cylinder followed by a few days of sitting.

If you pull the plugs and the engine won't roll over then the issue is with the rings. If you pull the plugs and the engine rolls over with water spraying out of the plug hole then, yes, it was hydrolocked.

Have you observed what "lots of rust" looks like or are you going on someone's word?

On thing I picked up on reading your post a second time, based on what you say they put the boat in and then said it was hydrolocked? An interesting tid bit of information is whether or not they actually started the boat OUT of the water successfully before splashing it. A hydro-lock condition can occur for less sinister reasons is why I say this. I'll get back to that point in a second...

I would think that any reputable marina would during the winterization process backfill the block with antifreeze, reason being there is no way to completely evacuate all the water from the block therefore the antifreeze backfull will prevent those pockets that retain a little water after draining from freezing potentially causing damage to the block or popping a freeze plug. So if that was done you'd think that they would at minimum drain out the antifreeze or start it up out of the water to flush it all out and not into the lake.

Back to the hydro-locking, it is possible to hydro-lock an engine if it begins to diesel or backfires in the water. Depending on the age and make of the powerplant some were not very well protected against the engine's ability to actually draw\suck water back in through the risers if the crank managed to reverse direction even if just for a second.

One other thought on the rusting in the cylinders... it is possible that if you had a breech between your combustion chamber and your water jacket in the block over the course of the winter fluid could leak down into the cylinders and sit there for months which could cause significant corrosion. That could be anything from a crack in the block, head or bad gasket such as the head gasket. That said if you had a breech typically that is accompanied by a noticeable lack of performance and a rough running engine. Usually a simple compression test or cylinder leak down test would confirm that as a possible culprit.

How does an engine reverse rotation and suck water in?

Well first of all it shouldn't reverse rotation, however it is possible with a misfire (engine firing out of time). If you consider conceptually how an engine works during the down stroke of the piston it creates a suction into the cylinder typically for the purposes of bringing in fresh air and fuel mixture. The valves of course are timed to open and close with the stroke of the engine. So as you go through the strokes the engine will accomplish in one complete cycle, piston goes from the top of the stroke and proceeds down, the intake values open and allow fresh air and fuel in (or the fuel injectors fire at that time) as the piston bottoms out the intake values close and the compression stroke begins where the piston moves up compressing the air fuel mixture till the top of the stroke where the spark plug fires and thus results in the power stroke where that explosion pushes the piston down with force as it burns and expands, finally the piston will take one more travel up and as it does so the exhaust values will open expelling the exhaust. It's at this time if there is a misfire it is possible to actually suck water back into the engine through the exhaust valves. Why? Well the exhaust outlets actually contain water at a stand still, this is used as a muffler of sorts and creates back pressure for the engine. Depending on how that is designed, and some were poorly designed, with little effort the potential reversal of the piston with the exhaust valves open could allow water to be pulled into the cylinder and thus create the environment for a possible hydro-lock.

One other condition that can do this is if the boat is travelling at speed and the engine conks out, the back wash at the transom as the boat loses speed and comes off plane can create enough of a back flow of water to force it into the engine even if it is not moving.

Yeah, I thought more about it after I posted and pretty much arrived at what you just typed. Logged back in to edit my post but I am clearly too late.

On a 4-cycle engine the intake stroke and exhaust stroke are the two times where this could occur.

Sorry to make you type all that.

Even if winterized and fogged, motor can get all these symptoms from the forklift on the way to the rack. Just tip the boat toward the bow and the water/antifreeze mixture sitting in the exhaust can flow back into the cylinders. If the yard was responsible for winterizing and launching, this is 100% on them regardless of cause because they caused it.


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https://uploads.tapatalk-cdn.com/201...6d44f0591a.jpg

Thanks for all the good comments. Much appreciated. Here is one picture I got from the marina



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That doesn't look terribly bad, hard to see if there is any scoring in the cylinder walls but that little bit of rusty stuff doesn't look like a catastrophic problem. I've tore apart running motors that looked far worse.

That is not hydrolock. That is piston ring seizure from poor winterization.

If I were in your shoes, I would not let this place perform any more work on my boat. They've done enough.

Soak the cylinders in Marvel and get the engine to roll over by hand. Reinstall the heads, bump the key 10-15 times to get the oil moving, then compression/ leakdown test.

Winterization
 

My marina, will take care of anything that they screwed up. It's on the winter storage contract. Most marinas have insurance and they cover it. A few folks had cracked blocks etc sue to improper storage. The marina took care of it and replaced the block with a remanufactured block.

As far as hydrolock, usually happens at idle when the water is forced back up into the exhaust due to a wave. I just remove the plugs, churn the motor over a few times to remove the water, spray a generous amount of MMO in the cylinders, churn it over a few more times, and replace the plugs. You may need starter fluid to start the engine as the MMO is heavy.

How does the marina explain the problem?
This is clearly their fault and I would have your lawyer send them a friendly request to make it right if they don't step up on their own.

Take a closer look at his picture guys. There is a rust line across both pistons that indicates to me that standing water was in the combustion area for a while. Looks like poor winterization or water got into the engine somehow creating the aforementioned hydrolock.

Strange Cropping
 

I'd like to see the entire photo with all 4 holes completely visible. The current photo with a little more than half of 2 cylinders doesn't tell the whole story.

https://uploads.tapatalk-cdn.com/201...74c3c1202a.jpg



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Charlie T, thanks for looking at the pic. Any thoughts appreciated!


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water in cyl
 

First off I do not have a dog in this fight. I do not know the owner, or the marina that winterized this boat. No where is any history of the motor mentioned. How old?? How many hrs?? Salt water use??
The owner says the motor ran well. It may have appeared to run well, but compared to what?? As a motor gets tired, it may still run smooth, but as it aged its hard to notice a power decrease.
If you look close at all 4 cyl, the top of the gasket has a noticeable carbon ring evenly around all cyl except where #4 and #6 meet the lower water jacket. I think there was a compression leak between 4&6. I also think the heat from this compression leak compromised the head gasket at the water jacket. The compression leak between #4 and #6 is not uncommon in motors that are run wide open when bone cold. The head heats up at a different rate than the block, and this can cause premature failure of the head gasket.
Now I am going to stick my neck out, and give my opinion.
If I were sitting on the jury, I would say this motor had issues before it was winterized.
Peace My Friends, MOXIE

Drops Mic :laugh: