Hydrolocked? Yanmar 4JH2-TE

[skipperpete]

Originally Posted by IsaakOker

https://ibb.co/pdWzdDd

https://ibb.co/sPWG1m3

https://ibb.co/xXTc0PY

https://ibb.co/BrG1R4w

https://ibb.co/ydcdNyQ

https://ibb.co/sgWYj9N

https://ibb.co/v4L9BVP

https://ibb.co/FDNFwRC

Thanks for the photos, it looks rough but might clean up. I'm also interested to know if you can get a bit of rotation now. Did the sump level rise? I have a concern that the water that was in the cylinders may have drained onto the crankshaft and into the bearings, both main and at least a couple of conrod bearings.
The injector pump in one of your pics looks very shabby and I doubt that the stop could work. Does the turbocharger still turn or did the water damage it?

[IsaakOker]

Originally Posted by jimbunyard

Does the engine turn over now?

I don't see anything in the top end that would preclude it from doing so; you're almost certainly wasting your time by trying to free it up with oil in the top of the cylinders.

As for what is holding it, at this point we're all just guessing. Did you take the raw water pump off as suggested?

When you removed and replaced the starter, did anything fall off the old starter and go into the flywheel housing?

Did the engine have oil in it when you initially tried to start it?

There's no need to put the head back on to pull the engine out. As previously advised, just take a head bolt to the auto parts or fastener store and get two that fit and are about a couple of inches or 50 mm or so long, and use those and a piece of chain to pull the headless engine out. It'll be much easier because of the reduced size and weight, and it may help to balance or angle the engine, as required for your application, in removal. The manufacturer-supplied lifting points are often not as well-placed for specific installations as they could be...

Though it's notoriously difficult to tell from pictures, there doesn't seem to be any serious mechanical problem with the top end, all the cylinders are equally carboned, and there are no apparent leaks from either coolant or compression in the head gasket, at least that I can see.

While you've got access to the freshwater pump and its' rounded-off bolts, remove and replace them or have someone else do it.

No, the engine still doesn't turn nor move at all.

Nothing fell into the flywheel housing & nothing is missing on the starter as both bolts are still here.

I only checked the oil at the dipstick before turning it over 2 weeks ago and it was withing the margins, quite clear for a having been sitting for years & no water to be seen. I actually checked several times, in case.

The head gasket is still one piece so there shouldn't have been any leaks but the 4th opening of the heat exchanger had a very very worn out gasket, for sure not sealing anymore.

I'll definitely sort the bolts on the fresh water pump out before reinstalling the head. I suppose I'll change the gasket while I'm at it.

Yes, I took the raw water pump out after the tip came through, turned just fine with some resistance of the Impeller, the gear on the engine seemed bright grey, very clean.

Thanks for the tip with the head bolt, I'll get 2 or 3 of those!
Probably will pull engine out tomorrow or so.

I still think that the gearbox might be an issue but I can move the lever and engage, disengage easily so clueless...

[IsaakOker]

Originally Posted by skipperpete

Thanks for the photos, it looks rough but might clean up. I'm also interested to know if you can get a bit of rotation now. Did the sump level rise? I have a concern that the water that was in the cylinders may have drained onto the crankshaft and into the bearings, both main and at least a couple of conrod bearings.
The injector pump in one of your pics looks very shabby and I doubt that the stop could work. Does the turbocharger still turn or did the water damage it?

Nope, no rotation at all and I'm starting to round off 2 corners of the crankshaft bolt..

Sump level still the same If I recall right. Still no signs of water on the dispick..

The turbo fan moves but the outlet is very carboned up so I don't want to move it until I clean that.

The entire engine looks horrible from the outside. That's why I was skeptical about taking the head off as I wanted to clean off as much as I could before.
The block and therefore the pump haven't been wire brushed yet, looks very bad but is only paint and superficial rust.
The stop doesn't move though, not easily at least.


I'm going to get the oil, paper, sponges, etc to clean this up a bit and then I'll post a lot more detailed photos.

[Geoff54]

You are getting lots of advise - my 2 cents..

Getting rid of that surface corrosion so you can see how deep the pitting is a good idea. You probably know this but scrub around the bore, not up and down. Give it a good soak in PB Blaster, Kroll or similar and then see if you can break it free. Once free, I wouldn't turn the engine over because the rust can score the bores. Put some engine oil around the edge of the piston crowns and remove them through the top. Clean the bores thoroughly and then you can see exactly what you are dealing with. BTW, keep the piston, rod and rod cap together and know which bore they correspond to. (Sorry if I'm telling you things you already know).

+1 pistons are available but not cheap or a machine shop could re-sleeve. BUT it was fresh water so maybe the corrosion isn't too deep and, while it's difficult so tell, I don't see any sign of a wear step - I'm betting you can get away with a flex hone and new rings. Or see if a machine shop can use a bore hone and still keep it within spec. But you need get everything free and clean to tell.

What is your goal? Is this long term keeper, in which case you might want to get everything perfect? Or do you just want to get things "acceptable"? As you might find from another thread, Yanmars tend to smoke a bit anyway. And parts aren't cheap, so....

Pull the valves as soon as you can to see if there is corrosion in there also.

Fingers crossed for you.

[IsaakOker]

Originally Posted by Geoff54

You are getting lots of advise - my 2 cents..

Getting rid of that surface corrosion so you can see how deep the pitting is a good idea. You probably know this but scrub around the bore, not up and down. Give it a good soak in PB Blaster, Kroll or similar and then see if you can break it free. Once free, I wouldn't turn the engine over because the rust can score the bores. Put some engine oil around the edge of the piston crowns and remove them through the top. Clean the bores thoroughly and then you can see exactly what you are dealing with. BTW, keep the piston, rod and rod cap together and know which bore they correspond to. (Sorry if I'm telling you things you already know).

+1 pistons are available but not cheap or a machine shop could re-sleeve. BUT it was fresh water so maybe the corrosion isn't too deep and, while it's difficult so tell, I don't see any sign of a wear step - I'm betting you can get away with a flex hone and new rings. Or see if a machine shop can use a bore hone and still keep it within spec. But you need get everything free and clean to tell.

What is your goal? Is this long term keeper, in which case you might want to get everything perfect? Or do you just want to get things "acceptable". As you might find from another thread, Yanmars tend to smoke a bit anyway. And parts aren't cheap, so....

Pull the valves as soon as you can to see if there is corrosion in there also.

Fingers crossed for you.

Your opinion is very very welcome.. I'm not sure if I seem to know what I'm doing but very honestly, I'm don't know much about engines but I've been working a lot on boats so I suppose I'm used to the chit chat & general interest in things.

This is a long term project.
It's a sailboat I just bought to redo some cabinetry and cosmetic work but the engine has come in between.
I was expecting to pull the engine, change heat exchanger, turbo, elbow, intake Manifold, pump gaskets & seals as well as impellers, hoses, engine mounts and a paint job but wasn't expecting a rebuild.

So, as I'm keen on working and feel confident, I'll keep on going with you very much appreciated Tips.

Just one thing, to take to crowns off, in case I can get the engine to turn, I have to release 2 bolts from the connecting rod right?

I'm quite far from that stage as I first have to take the engine out and roll it... And before that, try to get this pistons to move... Any other way of forcing it to move that's no the main crankshaft bolt(it's getting round)?

Also, now that I'm asking.
What products do I need to clean the turbo(I know it's very delicate), heat exchanger, elbow, intake Manifold, cylinders, etc?
Does water, 15w40, 800grit sandpaper, scotch Brite & diesel do the job?

[Cheechako]

Originally Posted by IsaakOker

Nope, no rotation at all and I'm starting to round off 2 corners of the crankshaft bolt..

Sump level still the same If I recall right. Still no signs of water on the dispick..

The turbo fan moves but the outlet is very carboned up so I don't want to move it until I clean that.

The entire engine looks horrible from the outside. That's why I was skeptical about taking the head off as I wanted to clean off as much as I could before.
The block and therefore the pump haven't been wire brushed yet, looks very bad but is only paint and superficial rust.
The stop doesn't move though, not easily at least.
I'm going to get the oil, paper, sponges, etc to clean this up a bit and then I'll post a lot more detailed photos.

I wouldn't bother with anything else until it will turn at least just a smidge. You are wasting time if it wont turn. Heck, the crank could be scored, burned and heat seized.
Did you try rapping on the piston tops with a block of wood to free them?

[Cheechako]

Originally Posted by Geoff54

You are getting lots of advise - my 2 cents..

Getting rid of that surface corrosion so you can see how deep the pitting is a good idea. You probably know this but scrub around the bore, not up and down. Give it a good soak in PB Blaster, Kroll or similar and then see if you can break it free. Once free, I wouldn't turn the engine over because the rust can score the bores. Put some engine oil around the edge of the piston crowns and remove them through the top. Clean the bores thoroughly and then you can see exactly what you are dealing with. BTW, keep the piston, rod and rod cap together and know which bore they correspond to. (Sorry if I'm telling you things you already know).

+1 pistons are available but not cheap or a machine shop could re-sleeve. BUT it was fresh water so maybe the corrosion isn't too deep and, while it's difficult so tell, I don't see any sign of a wear step - I'm betting you can get away with a flex hone and new rings. Or see if a machine shop can use a bore hone and still keep it within spec. But you need get everything free and clean to tell.

What is your goal? Is this long term keeper, in which case you might want to get everything perfect? Or do you just want to get things "acceptable"? As you might find from another thread, Yanmars tend to smoke a bit anyway. And parts aren't cheap, so....

Pull the valves as soon as you can to see if there is corrosion in there also.

Fingers crossed for you.

OP: The only thing I will add is if you take the pistons out the top you need to get rid of the ridge with a ridge reamer first.

But it sounds to me like you are not a mechanic and will/should leave all of this type of stuff to one!

[IsaakOker]

Originally Posted by Cheechako

I wouldn't bother with anything else until it will turn at least just a smidge. You are wasting time if it wont turn. Heck, the crank could be scored, burned and heat seized.
Did you try rapping on the piston tops with a block of wood to free them?

Hii Cheechako,

You're right, I'm not a mechanic at all. But I want to clear doubts as much as I can before I as a mechanic to do anything..

Obviously the first thing I want is to get the pistons loose before I start cleaning/inspecting any further but I've been pulling a 1/2" wrench with a 6ft pole and am worried to break off the crankshaft bolt as I bet it's not easy to get a broken one out..

[Cheechako]

Originally Posted by IsaakOker

Hii Cheechako,

You're right, I'm not a mechanic at all. But I want to clear doubts as much as I can before I as a mechanic to do anything..

Obviously the first thing I want is to get the pistons loose before I start cleaning/inspecting any further but I've been pulling a 1/2" wrench with a 6ft pole and am worried to break off the crankshaft bolt as I bet it's not easy to get a broken one out..

I hope you mean a 1/2" drive socket wrench or breaker bar! I doubt you can break a crankshaft bolt. But yeah, if it doesn't break loose fairly readily no point in overdoing it. You need to shock those pistons loose. Use the hammer and wood. Then try turning it.

But thinking about it, the rusted scored cylinder shows in your picture above the piston... That indicates to me that is HAS turned. (the piston moved from the scored area) That's either good news or bad. If it's not moving and that shows, the previous owner damaged it and the piston stopped where it is. Who knows what happened.

[IsaakOker]

Originally Posted by Cheechako

I hope you mean a 1/2" drive socket wrench or breaker bar! I doubt you can break a crankshaft bolt. But yeah, if it doesn't break loose fairly readily no point in overdoing it. You need to shock those pistons loose. Use the hammer and wood. Then try turning it.

But thinking about it, the rusted scored cylinder shows in your picture above the piston... That indicates to me that is HAS turned. (the piston moved from the scored area) That's either good news or bad. If it's not moving and that shows, the previous owner damaged it and the piston stopped where it is. Who knows what happened.

Yep, a socket wrench.

That's what I thought so I started tightening the crankshaft bolt again but It doesn't move at all..

The previous owner let it rot here where it is, don't think he ever tried turning it over in 5 yrs.

I'll try to upload a video of me trying to crank it 2 weeks ago so that you can habe a Listen to it but it sounded quite healthy to me despite it not wanting to run(one fuel return pipe of a injector was corroded through so was leaking fuel).

[jimbunyard]

Saildrive or straight inboard? If inboard, with the gear in neutral, can you turn the prop shaft? If not, there may be something wrong in the gear. If you can, there is likely nothing wrong with the gear.

At this point, if you have room and are concerned with the gear (and you have an inboard), since it has to be removed anyway, you might be able to separate it from the engine enough to see if it frees the engine.

The rust in the 2nd or 3rd cylinder (4th picture) didn't happen in 10 days. Was the boat stored in a humid environment with large daily temperature swings?

As Geoff notes, a lot depends on your projected use and pocketbook. It is unlikely that the rust in the bad cylinder will clean up completely even with a good honing; the engine can probably be made to run, and maybe run pretty well, with just a good hone, valve job and new bearings, but a fairly high performance, turboed engine really needs to have balanced compression on all four cylinders.

[Cheechako]

Oh geez, in your first post I took this : "So I suspect that 2 weeks ago when making the engine turn over it hydrolocked with fresh water(lake) as it never fired up to get rid of the water." to mean it cranked recently.

SO I'm way out in left field on this whole thread. Just remove the engine and get it apart. 5 years it's not gong to be salvageable as is.

[IsaakOker]

Here's a link to it turning over literally 2 weeks ago, not kidding.

Im the least of a mechanic here so it all surprises me the most but I'm sure I'll get a way to find the issue at least.. That's my first aim before attempting to repair anything..

https://youtu.be/EMurJcBiO5E

[IsaakOker]

Originally Posted by jimbunyard

Saildrive or straight inboard? If inboard, with the gear in neutral, can you turn the prop shaft? If not, there may be something wrong in the gear. If you can, there is likely nothing wrong with the gear.

At this point, if you have room and are concerned with the gear (and you have an inboard), since it has to be removed anyway, you might be able to separate it from the engine enough to see if it frees the engine.

The rust in the 2nd or 3rd cylinder (4th picture) didn't happen in 10 days. Was the boat stored in a humid environment with large daily temperature swings?

As Geoff notes, a lot depends on your projected use and pocketbook. It is unlikely that the rust in the bad cylinder will clean up completely even with a good honing; the engine can probably be made to run, and maybe run pretty well, with just a good hone, valve job and new bearings, but a fairly high performance, turboed engine really needs to have balanced compression on all four cylinders.

It's a straight inboard.
I'll try moving the shaft, cleaning the top part of the cylinders, etc in a while and then I'll upload more pictures to see how bad the visible parts are really.

Yes, the boat was in GA on a lake, 5 yrs locked up.
Extremely humid, therefore the exterior rust of the engine but despite all this, the crankshaft was turning before I bought the boat, that's for sure..

It's a mystery to me so let's see if I can solve it ASAP and then I can ask for help at repairing it(if possible)

[Geoff54]

Sorry that you are not a little closer. I'm getting old and I'd gladly trade you an engine rebuild for some boat yoga.

Originally Posted by IsaakOker

Just one thing, to take to crowns off, in case I can get the engine to turn, I have to release 2 bolts from the connecting rod right?

Yep! IIRC Yanmar caps are marked but make a note of the orientation, just in case.

Originally Posted by IsaakOker

Also, now that I'm asking.
What products do I need to clean the turbo(I know it's very delicate), heat exchanger, elbow, intake Manifold, cylinders, etc?
Does water, 15w40, 800grit sandpaper, scotch Brite & diesel do the job?

I'm going to pass on this because I have limited experience with turbos. Those that I've owned or delt with have all been very reliable or shipped off to the turbo shop.

Originally Posted by Cheechako

I wouldn't bother with anything else until it will turn at least just a smidge. You are wasting time if it wont turn. Heck, the crank could be scored, burned and heat seized.
Did you try rapping on the piston tops with a block of wood to free them?

+1 Although, in that the engine hasn't been run since it was able to be turned over, Heat seized is unlikely.

Originally Posted by Cheechako

OP: The only thing I will add is if you take the pistons out the top you need to get rid of the ridge with a ridge reamer first.

I'll wait for more information/pictures on this but from the pictures so far, I doubt a a ridge reamer would be needed to remove the pistons. Maybe before reinstalling but it takes a lot of wear to prevent piston removal. If it's really that bad, I'd pull the crank and remove them through the bottom and then deal with the ridge. But that's just my way.