Advice Sought. Engine Seized after installing Injection pump

[dukey]

The injector gear is now out so a seized injector pump is eliminated. The gearbox was not really used in the testing because the engine stalled when put into gear,forward or reverse. I assume because of the air build up in the fuel line and or starvation of fuel. This I assumed was the lift pump but I am now suspecting the injection pump.

When you said the above I reckoned that somebody (that hard working guy ) would question the engine stalling when the gearbox is engaged. I think this should be explored. Difficult but imho necessary.

[RaymondR]

If it's a cup and cone type marine gearbox they usually freewheel in one direction when in gear. I cannot envision a circumstance whereby this type of gearbox could be stuck in both forward and reverse at the same time.

Remove the injectors and use a piece of dowel and a ring spanner which will apply rotation both ways on the crankshaft. Work the wrench back and forth with the dowel pressed down on the piston top and you may be able to feel which or whether it is a, or more, piston(s) corroded into the cylinder. A dial gauge might give a better indication.

[Jack C]

Originally Posted by RaymondR

If it's a cup and cone type marine gearbox they usually freewheel in one direction when in gear. I cannot envision a circumstance whereby this type of gearbox could be stuck in both forward and reverse at the same time.

Remove the injectors and use a piece of dowel and a ring spanner which will apply rotation both ways on the crankshaft. Work the wrench back and forth with the dowel pressed down on the piston top and you may be able to feel which or whether it is a, or more, piston(s) corroded into the cylinder. A dial gauge might give a better indication.

Raymond, it is the cone type gearbox. Unlikely that the gearbox is the problem unless something at the input of the gearbox jammed.

I removed the injectors. The hole is about 1 mm diameter, just enough for the pintle type injector to fit. So no access for dowels although maybe the glow plug hole would be bigger?

[RaymondR]

Originally Posted by Jack C

Raymond, it is the cone type gearbox. Unlikely that the gearbox is the problem unless something at the input of the gearbox jammed.

I removed the injectors. The hole is about 1 mm diameter, just enough for the pintle type injector to fit. So no access for dowels although maybe the glow plug hole would be bigger?

Sounds like the nozzle is still in the head and all you have removed is the spring and the pintle and left the housing in the head. The nozzle usually comes out with the outer housing and leaves a much bigger hole than 1mm.

[Jack C]

Originally Posted by RaymondR

Sounds like the nozzle is still in the head and all you have removed is the spring and the pintle and left the housing in the head. The nozzle usually comes out with the outer housing and leaves a much bigger hole than 1mm.

No, its a yanmar. The injector is out. A complete unassembled unit.

I have in the past disassembled the injectors, un seized the pintle etc. and then bought replacement housings with pintles.

Tiny hole.

[jimbunyard]

Time to start over from the beginning. Certainly wish some people would read the entire short thread before making repeat suggestions though.


What was the condition of the engine before you had the bad fuel issue?

How did it run, was it easy to start, did it idle well, did it accelerate smoothly throughout its rpm range, did it reach full rated rpm, did it smoke and if it did what color was the smoke? Did it overheat?

Even if there were 3600 hours on it, with even reasonable care the brief amount of test running you performed shouldn't have caused seizure, even if you'd run the engine with straight diesel as a lubricant. Diesel is oil, after all.

Of course, since we don't know what service the engine had, or didn't have, before, all bets are off; the engine won't turn.

Given the steps you've taken, some things can be absolutely eliminated; hydrolock, jammed lift or injection pump, jammed starter (if you're removed it), valve train problems (if you've removed the rocker arm shaft assembly).

What we've really not determined is how hard the engine is siezed. Since the limitation seems to be the crank pulley bolt, that must be overcome, which leaves either rocking it at the starter opening as previously described, or by affixing a bar to the crank pulley. In the parts catalog the crank pulley is shown with four holes in the front. If this is the case for your pulley, and if they are tapped, it is easy enough to put a couple of bolts in and lever the engine over with a piece of flat bar, or if you have a drill, for a more secure turning force, drill a couple of holes in a piece of flat bar or angle iron and bolt it to the pulley.

Earlier it was suggested that 'normally' a stuck valve won't cause an engine to sieze. It should be remembered that this is not a 'normal' situation, logically the process of eliminating potential problems should proceed from least to most difficult.

I'm curious about the previous service history, both recent and more long term. There are many different length bolts in the front cover/gear train area. It is difficult to tell if it's even possible from the exploded view, but I'm wondering if a bolt(s) got switched and is rubbing against a gear. Or something along those lines...

Of course at the end of the day, it may simply be that a piston or bearing has bound and caused the siezure, but that does seem counterintuitive given what we know so far.

[Jack C]

Originally Posted by jimbunyard

Time to start over from the beginning. Certainly wish some people would read the entire short thread before making repeat suggestions though.


What was the condition of the engine before you had the bad fuel issue?

How did it run, was it easy to start, did it idle well, did it accelerate smoothly throughout its rpm range, did it reach full rated rpm, did it smoke and if it did what color was the smoke? Did it overheat?

Even if there were 3600 hours on it, with even reasonable care the brief amount of test running you performed shouldn't have caused seizure, even if you'd run the engine with straight diesel as a lubricant. Diesel is oil, after all.

Of course, since we don't know what service the engine had, or didn't have, before, all bets are off; the engine won't turn.

Given the steps you've taken, some things can be absolutely eliminated; hydrolock, jammed lift or injection pump, jammed starter (if you're removed it), valve train problems (if you've removed the rocker arm shaft assembly).

What we've really not determined is how hard the engine is siezed. Since the limitation seems to be the crank pulley bolt, that must be overcome, which leaves either rocking it at the starter opening as previously described, or by affixing a bar to the crank pulley. In the parts catalog the crank pulley is shown with four holes in the front. If this is the case for your pulley, and if they are tapped, it is easy enough to put a couple of bolts in and lever the engine over with a piece of flat bar, or if you have a drill, for a more secure turning force, drill a couple of holes in a piece of flat bar or angle iron and bolt it to the pulley.

Earlier it was suggested that 'normally' a stuck valve won't cause an engine to sieze. It should be remembered that this is not a 'normal' situation, logically the process of eliminating potential problems should proceed from least to most difficult.

I'm curious about the previous service history, both recent and more long term. There are many different length bolts in the front cover/gear train area. It is difficult to tell if it's even possible from the exploded view, but I'm wondering if a bolt(s) got switched and is rubbing against a gear. Or something along those lines...

Of course at the end of the day, it may simply be that a piston or bearing has bound and caused the siezure, but that does seem counterintuitive given what we know so far.

Answers to your questions.

Before fuel issue, engine was fine. No symptoms or problems.

Boat was a Sunsail charter from new 2010 to 2016 then not used a lot 2016-2018 then I bought it and was mostly unused. This caused the fuel muck problem.

Have not removed the rocker arm assembly, but valves, push rods etc look fine. If there was a jammed valve, I would see it? I dont see how removing the rocker arm assembly would help.

Nice suggestion on bolting a flat to the pulley to try to move backwards. Will try it.

Gear cover looks like it was never opened, so I doubt if its the wrong bolt issue.
Next for me is to inspect the gears.

Keep the suggestions coming.

[Don C L]

So, just to be clear, it never ran, or even turned over, with the new lift pump, right? And the timing was still set correctly. How long was it sitting there before you got the new lift pump? And you did not remove the starter motor in this process, right? I am looking forward to what you see in the gears.

[Jack C]

Originally Posted by Don C L

So, just to be clear, it never ran, or even turned over, with the new lift pump, right? And the timing was still set correctly. How long was it sitting there before you got the new lift pump? And you did not remove the starter motor in this process, right? I am looking forward to what you see in the gears.

Yes it never ran, or even turned over, with the new lift pump, and the timing was set correctly.

It sat about a week with oil drained while I waited for the new lift pump. After installing the new lift pump I poured 1 liter oil into rocker cover and tried to turn over the engine. That when I discovered it was seized.

I loosened the starter motor but left it hanging on the bolts after it seized to check if it was stuck engaged.

Today I tried to pull the crank shaft pulley. I broke the puller in the attempt. So no access to gears yet.

I went to spray more liquid wrench into the injector ports. Cylinder #2 which is up with both valves closed was still full of liquid after 24 hours.

I would have assumed that the liquid wrench would have found its way past the rings? Maybe the rings on piston #2 are seized?

[jimbunyard]

Originally Posted by Jack C

Answers to your questions.

Before fuel issue, engine was fine. No symptoms or problems.

Boat was a Sunsail charter from new 2010 to 2016 then not used a lot 2016-2018 then I bought it and was mostly unused. This caused the fuel muck problem.

Have not removed the rocker arm assembly, but valves, push rods etc look fine. If there was a jammed valve, I would see it? I dont see how removing the rocker arm assembly would help.

Nice suggestion on bolting a flat to the pulley to try to move backwards. Will try it.

Gear cover looks like it was never opened, so I doubt if its the wrong bolt issue.
Next for me is to inspect the gears.

Keep the suggestions coming.

The point to removing the rocker gear is that it eliminates that potential problem immediately, and is very simple to accomplish; you just remove 3 bolts. If you don't remove the pushrods or mess with the valve adjustment, to put it back all you do is reinstall the three bolts. You can't tell if anything is 'stuck' just by looking at it. Since you can't turn the crank backwards, you've no real idea if anything in the valve train is amiss or not.

There are no absolutes here, that the liquid stays in the#2 cylinder to me would indicate that that cylinder is in good shape; if the bore was scuffed or scraped from a recent running issue, the liquid would more than likely escape through the scuff marks and scoring. For an engine that has sat for a long time, 'siezed' rings (actually pistons) will corrode almost solid into the bores and not 'drain' down, but this takes years, not a week.

If you broke a puller trying to remove the pulley, you either had one that was too small or the wrong type. Better to concentrate first on getting a positive method for turning the crank in both directions.

[hpeer]

FWIW
may help the conversation

[hpeer]

The engine was running fine.
You removed and remounted the injector pump.
Not the engine will not turn.
The injector pump gear, is connected to the idler, is connected to the crank shaft.
The idler also appears to turn the cam shaft.

You touched the injector pump.
Somehow that cocked up the gear alignment with the idler OR idler to crank shaft. Gears are jammed.

Gear misaligned? I do not know. It appears to be a huge pain to expose those gears. I would be tempted to thump the injector gear or idler in reverse if accessible.

Even if I am right I would be nervous lest it repeat unless I had some good explanation.

Any way this is my guess and why.

ALWAYS go to the last thing you did.

I am wishing you very good luck. I have been there and it sucks.

[jimbunyard]

Except

"The injector gear is now out so a seized injector pump is eliminated. "

See post 10.

[hpeer]

Jim,
The pump is out but the idler is in, no?

Idler could be jammed to crank gear.

But also, and I can’t tell clearly from this drawing, do you remove the gear when removing the pump or just take off the flange? IOW, is the GEAR out because the pump is out?

[skipperpete]

Originally Posted by Jack C

No, its a yanmar. The injector is out. A complete unassembled unit.



I have in the past disassembled the injectors, un seized the pintle etc. and then bought replacement housings with pintles.



Tiny hole.

Yep, precombustion chamber down there so no chance of getting your borescope in, only fluids.
Pete