Advice Sought. Engine Seized after installing Injection pump

[Mike Banks]

Remove starter motor and check it is not seized. If, when you have it removed, you can see the ring gear, try to move the engine using a screwdriver on one of the cogs.

If the engine will not move, and the injectors are out, try to suck out each cylinder using a brake n bleeder pump or a to see if diesel or sea water or coolant is in there. You may have blown a gasket and have a cylinder full of coolant.

Diesel in the oil is almost always a fuel pump diaphragm or a faulty seal somewhere in the fuel system.

[Gregg927]

I may seem far-fetched in this, but, I had an almost identical problem with a chainsaw. It turned out that a part from the carburetor had been ingested into the cylinder and was lodged perfectly so the piston would not move at all. Just an idea, I’m struggling to coming up with something better.

Good luck sailor.

[hpeer]

I don’t know your engine. But I have removed and replace an injection pump on a 4JH4.

I am told that normally the injection pump is driven by a 2:1 reduction ratio gear from the crankshaft. In the 4JH4 there is an idler between the pump and the crankshaft gear. That idler may not be relevant here.

As you have removed and replaced this pump is it possible that something is jamming the two (or more) gears? Suppose something, God knows what, fell into those gears and is now jammed in there.

I only say this as it seems to the the last thing you were working on before the problem, thus it is more suspect than other items.

Just imagine a washer in the gears. I know you took the pump out. Did you remove or uncover the drive gears?

Sorry if this is not helpful. Best I can think of not already covered.

[Jack C]

Originally Posted by double u

@seizure: I wonder if an engine seizure can even occur after it has been stopped (apart, o0f course, by water entering). Wouldn't an e.s. show up as engine is by itself quickly reducing revs until standstill? Just guessing...
timing gears would jam without a big bang when running? Same with a stuck valve: no nasty sounds?

You make a very good point.

This what happened:

Engine ran. It ran for a few minutes at high rpm, would not idle. Stalled at low revs. Then I drained all the oil. It sat for about a week.

Then I replaced oil filter, Added 1 liter oil and found the engine seized.

So the seizing happened gradually. No bangs. So valve did not hit piston and gears did not suddenly jam.

What can cause a gradual seize.
Liquid in cylinders. But injectors are out and still seized.
Oil ring on piston seized due to poor lubrication? Maybe.
Crankshaft bearings through oil starvation? Maybe, but no metal bits in oil filter or oil.

So now its down to daily adding of penetrating oil. Yesterday I noted that after filling with oil, one cylinder retained the oil while the others drained. Maybe stuck rings or maybe I did not add enough oil to fill the cylinders which were lower. Today I will take a fine rod to check cylinder position and will add more oil.

Also today I check the valves. A large gap between rocker arm and valve stem cap will indicate a stuck open valve.

Next episode in a few hours.

[skipperpete]

Stalling at low revs could very well have been caused by early main bearing seizure, it’s surprising how little it takes to lock up a crankshaft. I can’t figure out any scenario where this can be fixed without invasive surgery.
If I was doing the job it would be.....Gearbox off and try to rotate again ....then head off and take a look at the pistons and liners...... finally, lift er up and drop off the oil pan, undo the main caps and take a close look at the bearings.
Because there’s no bearing metal in the filter paper doesn’t mean a seizure didn’t happen, it simply means it happened very quickly .....without shedding a lot of flakes. The shells might be bonded to the main journal. The upside of that is that the damage is often less because it’s usually only one journal and the rest if the journals didn’t get metal particles through them.

[double u]

the near-running away & not wanting to idle is suspicious to me. How can this happen? Supposedly very worn rings can make the engine run away on it's own lubricating oil...
On the job we had a 3GM30F once seize & in the end bend two connrods (cooling water disappeared through boiler, but it started again after the first two seizures (it took us a while to discover the lack of cooling water...fresh water cooled). Each seizing was unmistakable: rapid decline of revs until stopped, but engine was not "frozen" afterwards.
piston against stuck valve: I guess you could turn the engine a little backwards, "away" from the valve.

[double u]

have you taken a look into the cylinders through the injector holes? (endoscope?)
engines sometimes die in mysterious ways:
a 30hp Renault we had: stub of camshaft where the timing-belt-wheel sat crumbled, camshaft stopped - most pushrods bent. (dirty water blowing out the intake when trying to start...that was the giveaway). (not a lot of fun, as it happened half way up the Red Sea...)- so, small consolation, Tel Aviv is a much better place to have serious engine problems...

[Jack C]

Originally Posted by double u

the near-running away & not wanting to idle is suspicious to me. How can this happen? Supposedly very worn rings can make the engine run away on it's own lubricating oil...
On the job we had a 3GM30F once seize & in the end bend two connrods (cooling water disappeared through boiler, but it started again after the first two seizures (it took us a while to discover the lack of cooling water...fresh water cooled). Each seizing was unmistakable: rapid decline of revs until stopped, but engine was not "frozen" afterwards.
piston against stuck valve: I guess you could turn the engine a little backwards, "away" from the valve.

It was not a near run away. I opened the throttle. At the time I suspected that air was entering the fuel via the lift pump diaphragm and that the fuel was entering the engine also through the diaphragm. Now I suspect the injection pump.

I tried turning the engine backwards, but the crankshaft bolt just opened. This indicates to me that its stuck in both directions. I guess I could put it in gear and put a wrench on the prop shaft.

[Jack C]

Originally Posted by double u

have you taken a look into the cylinders through the injector holes? (endoscope?)
engines sometimes die in mysterious ways:
a 30hp Renault we had: stub of camshaft where the timing-belt-wheel sat crumbled, camshaft stopped - most pushrods bent. (dirty water blowing out the intake when trying to start...that was the giveaway). (not a lot of fun, as it happened half way up the Red Sea...)- so, small consolation, Tel Aviv is a much better place to have serious engine problems...

I have a boroscope, 5.5mm diameter. But the injector holes are tiny, maybe about 1.5mm diameter. And then what would I be looking for?

[Jack C]

Originally Posted by skipperpete

Stalling at low revs could very well have been caused by early main bearing seizure, it’s surprising how little it takes to lock up a crankshaft. I can’t figure out any scenario where this can be fixed without invasive surgery.
If I was doing the job it would be.....Gearbox off and try to rotate again ....then head off and take a look at the pistons and liners...... finally, lift er up and drop off the oil pan, undo the main caps and take a close look at the bearings.
Because there’s no bearing metal in the filter paper doesn’t mean a seizure didn’t happen, it simply means it happened very quickly .....without shedding a lot of flakes. The shells might be bonded to the main journal. The upside of that is that the damage is often less because it’s usually only one journal and the rest if the journals didn’t get metal particles through them.

Pete, great advice. Don't understand your upside comment. If metal comes loose on the crankshaft bearing it should drop into the pan and get caught in the oil filter. So the rest of the journals should not be affected.

And yes, metal in the filter only confirms a bearing problem. Lack of metal is not conclusive.

The adventure continues.

[Jack C]

Originally Posted by hpeer

I don’t know your engine. But I have removed and replace an injection pump on a 4JH4.

I am told that normally the injection pump is driven by a 2:1 reduction ratio gear from the crankshaft. In the 4JH4 there is an idler between the pump and the crankshaft gear. That idler may not be relevant here.

As you have removed and replaced this pump is it possible that something is jamming the two (or more) gears? Suppose something, God knows what, fell into those gears and is now jammed in there.

I only say this as it seems to the the last thing you were working on before the problem, thus it is more suspect than other items.

Just imagine a washer in the gears. I know you took the pump out. Did you remove or uncover the drive gears?

Sorry if this is not helpful. Best I can think of not already covered.

Thanks for the comment. I take the same approach. What was the last thing done.
In my case it was installing the lift pump. I thought that maybe it jammed the cam in the injection pump. Removed lift pump. No change.
Then I thought injection pump seized. Pulled of its gear, no change.
I never opened the gearcase so nothing dropped in there.
I did mangle the woodruff key when I reinstalled the injection pump. I thought I had all the bits but maybe something dropped down and somehow got into the idler gear in the area I cannot see.
So thanks for the idea. Its worth removing the gear cover and looking before a major step like removing the head, gearbox and hoisting the engine to check the main journals.

Your post is very helpful. Many thanks.

[sinnerman]

Instead of the engine being "seized", how about being "jammed".

Since the problems started with the injection pump, maybe it was not rebuilt/built correctly. This would explain the diesel in the oil.

Remove the injector pump assembly and see if you can rotate the engine.

On my engine (Kubota/Universal) the injector pump is driven by a small engine-internal camshaft. On the Yanmar, the camshaft is inside the pump itself and directly coupled to the engine.

If the pump is messed up inside, and the camshaft will not rotate, neither will the engine.

My two cents..

[Don C L]

Originally Posted by Gregg927

I may seem far-fetched in this, but, I had an almost identical problem with a chainsaw. It turned out that a part from the carburetor had been ingested into the cylinder and was lodged perfectly so the piston would not move at all. Just an idea, I’m struggling to coming up with something better.

Good luck sailor.

I had a similar thought. Given the description it sounded like some thing is jammed in somewhere.

[Wmkenney]

I second the thought of the engine being jammed up with a foreign object. Can you use a strap wrench to try and spin the crankshaft in either direction? The crankcase being overfull with diesel fuel as confirmed would suggest a leaking injector...unlikely to cause failure unless the engine got hydro locked, and now, with a bent connecting rod, won't turn over..all other steps taken so far have been spot on..good luck

[Stewie12]

Probably the seal on the injector pump allowing diesel into the engine was the cause of the original problem. The seal needs to one from the manufacturer.