CUMMINS 555’s

[Capt. Sea Fever]

My 1983 Grand Banks Classic 49 has two Cummins 555’s, 6020 hrs. on each.

Yesterday the SB engine wouldn’t start. My mechanic checked the starting battery....fine. I suspected a faulty starter, but he said it sounded like the starter was fine. The engine would not turn over.

The lights in the engine room dimmed considerably and the charge indicator showed a drop in voltage, but the engine did not turn over.

He then checked the oil....plenty, ....but he smelled diesel in the oil.
His diagnosis......a ruptured injector line.

A Cummins rep, 40 miles away, will charge me $500 just to drive down andthe back not including labor, parts, etc.

My question.......even if there’s diesel in the oil, shouldn’t the engine start? It was running fine about 2weeks ago.

I still suspect a faulty starter, but then there’s the oil issue too?? My sense of smell’s not the greatest, but I did not smell diesel on the dipstick.


Capt. Sea Fever

 

[bayview]

yes it would crank with fuel in the lube oil unless it seized up. Have you checked all electrical battery connections? Try to turn the engine by hand.

IMO you dont need a cummins guy to check connections, frozen engine, starter etc.

 

[DavidM]

This story doesn't add up:

How can the mechanic know that the starter's ok if it doesn't turn over? The lights dimmed which indicates that power is going to the starter but it doesn't move. Is the engine locked up? Did the mechanic try to bar it over by hand?

What does a ruptured injector line have to do with the engine not turning over?

Why did the mechanic conclude that the injector line was ruptured?

There is a simple paper towel test to confirm fuel in oil. Ski can elaborate as I have never done it. Did the mechanic do it?

This does not sound like a problem for a high powered Cummins mechanic, at least not the starting problem. Any mechanic with decent skills can get to the bottom of the starting problem.

It seems that you may have two unrelated problems: fuel in the oil possibly caused by a ruptured injector line and a starting (engine turnover) problem. Tackle the latter problem first and then look at the fuel problem.

David

 

[Ski in NC]

Take starter off and use a pry bar to try to rotate engine using flywheel teeth.

Or a wrench on front of crank, but I think (???) this has lots of allen screws (???).

Either way, want to see if engine is stuck.

Is oil level super high? If dilution with fuel is bad enough to seize engine, oil level will be inches above full.

Suck a little oil out of bottom of sump and see if there is water in there.

Start with the above.

 

[Insequent]

Those starters weigh a ton, hope you have good access! Check the starter solenoid - more likely to be an issue than the starter itself.

 

[tiltrider1]

If the injector failed and filled the cylinder with diesel then the engine would be hydrolocked. There is still the possibility that the starter is the issue but it does sound more like a hydrolocked engine.

 

[C lectric]

An injector line leaking is poor terminology. Unlike many other engines there are no injector lines, not even for a return line. There is a gallery [hole] in the cylinder head that not only feeds the injectors fuel but is also the return line for the excess that the injectors do not use. There is one external feed line from the PT pump to EACH cylinder head connecting at the cylinder head front. There is one external return line from EACH cylinder head at the back of each head.
No internal line that can leak into the engine.

To be fair he simply could have been talking the way many do about what he works on mostly but still know that those engines are like that and somewhat different.

Now the seals around the injectors could fail and leak fuel or coolant, either into a cylinder or into the valve cover area.

Do check for a hydrolock which could jam the engine/starter. Bar the engine over. The barring attachment should be right next to the PT pump.

So I'm going to suggest that you go to BOATDIESEL and join. Look through the PDF file [L.H. menu on the main page] section for:

Find: ASSOCIATED PRODUCTS
> Section. > Click ENGINES
>Sub Section. >click Cummins
>Products > click V555M

That will bring you to the V555M.

Look at the L.H. side of each listing and you will see [light lettering 14 - 19]
a series of sections 1 -5 of the V555M owners manual which describes a lot including the valve and injector settings and HOW to do it. Read it over.
14 -18 are the manual, 19 is the parts book.
Note these cover the natural mostly and a couple other engines so be carefull you understand which engine is referred to..

You will be allowed to download one section at a time, per day, as a level 1 member. They each are 6-10 Gbytes so take a while. Level 2 member more.

Find the barring description. Bar the engine over, not difficult but slow.
There should be compression resistance but that will release as you keep pressure on it and then it will carry on to the next cylinder. It will simply slow you but not stop you. Do two full rotations. If one cylinder is hydrolocked it will simply refuse to allow any further rotations, at least for a long time.

The barring description starts in section 3 so download that first.

Check the starter motor though as it could have developed a dead short which could prevent it from even attempting to crank the engine but also put a huge load on the batteries and cause a BIG Vdrop. A bearing could also have jammed preventing the starter from turning and creating the Vdrop.

I hope for your sake it is the starter. Not that the other isn't repairable but a starter will be a days job if access is reasonable. It is heavy , about 60 or so lbs so be sure you have control of it. You will need a LONG extension and 1/2" drive handle. If memory serves the socket will be 9/16 or 5/8. Upon more thought?? may it's 3/4". Easily checked as two of the securing bolts are accessed easily, it's the one behind the long extension is required. Some of those big old starters have a removeable end cover separate from the bearings which can be removed for brush access. THat could also enable you to try rotating the armature as a rough check if it is jammed. Don't know what you have now as many have had replacement starters over many years but take a look.

Diesel in the oil can be checked with an oil test.
Get an oil test kit and send a sample with a note that you are specifically concerned about diesel fuel in the oil and ask them to E-mail or phone you.

A redneck way [courtesy Ski in NC] is a drop of oil on a white paper towel. If only one dark ring shows it's oil, if a second much lighter ring shows there is diesel. It's not conclusive but indicative.

Enough for tonight,


This link may get you closer without all the button pushing.
If not then you will have to go through what I outlined above.
Link:
http://boatdiesel.com/PDFLibrary/Search/index.cfm?ProductID=4491

 

[FF]

While locked due to fuel on a sitting engine is possible , not that many boats have a gravity feed to the engine.

There is also a chance that the coolant or exhaust water has entered the not running engine .

If the engine is locked and can not be bared over with the starter gears ,

pulling all the injectors would be next step before attempting turning over.

 

[kapnd]

Drain the sump, then bump the starter to test, but don’t start the motor.
If the sump is really filled with diesel it creates a kind of an upside down hydro lock.
Don’t force the motor to turn, this could cause severe damage.
Diesel filled sumps are often caused by bad lift pumps or bad seals in hp pump.
Bad injectors are more likely to fill a cylinder, but can also drain down into the sump, especially on a high hour motor.

 

[Lepke]

First check the dip stick. Normal level means no diesel or little diesel in the fuel-also no reverse hydraulic lock.
Second turn the engine by hand. If it turns, probably bad starter. If it doesn't most likely hydraulic lock, since it was running ok prior. Any decent mechanic (even a non Cummings machanic with a manual) should be able to pull the injectors, drain any fuel in the cylinder and renew the seals.
http://boatdiesel.com is a good place for manuals and more detailed help in the forums. Many oem mechanics are active in the forums. I think $25 a year.

 

[Capt. Sea Fever]

Thanks to all!

Thanks to all for your comments!

We have not tried to turn over this Cummins 555 by hand.
My mechanic is confident that a (hopefully not many) cylinder(s) is hydrolocked by diesel.
So we’re going to diagnose the problem, and I’ll keep you posted.

Capt. Sea Fever

 

[Nidza]

Whatever it turns out to be, it would be good to also know what was the cause of the problem. I am very interested what is actually the problem and what caused it.

Since I have a similar engine to yours (V-504), only two simple things come to my mind how your engine could have been hydrolocked by diesel if everything else is functioning OK:

a) your fuel shutoff valve has malfunctioned or the wiring to it malfunctioned (leaving the valve open)

b) you have left the engine with the key in contact ON position (leaving the fuel shutoff valve in the open position again). Or some other switch which you use for that purpose if not the key.

For me, as electronic engineer it is a design fault, but those engines were designed in 1960's when there was not many electronics around engines. Anyway, they were aware of that problem and stated it as the warning in the user/operational manual for the engine. It says that fuel shutoff valve should be open only just prior to starting the engine and stay opened during the engine is working, and after engine shutdown by closing the fuel shutoff valve it should stay closed. If engine is not running, opened fuel shutoff valve, for prolonged periods, can cause a diesel hydrolock of cylinders. Now, how critical this is highly depends of how the fuel is being fed to the valve (gravity feed or something else,...). I was worried about this when installing everything, but connecting the oil pressure alarms (bell and light) to the key contact does add the confidence that it will not stay open for long periods (i.e. you have turned the contact on just to check something (read some gauge, check some alarm,...) and then you have forgotten to turn it off).

You are in the boating as well and therefore I am sure that you have not made this mistake, but we do often miss simple things, but they should be first checked and cost nothing.

 

[psneeld]

A tid bit passed along to me by an experienced mech....

"You can turn the 555 over by hand by using a pipe wrench on the crank pulley. You open the wrench just enough to fit the inner and outer circumference of the pulley, that puts a side load on the wrench but provides a lever the length of the wrench handle and permits easily turning the engine over. It is a hundred times easier than the built in jacking device back by the fuel pump.

Fuel locked ... yeah right, full of fuel for how long now? Those must be some really awesome piston rings!"

 

[Mr. Blu]

Have you checked the TDC pin in the engine? When it has come out, (for whatever reason) there is a possibility that it blockes the engine while trying to start. The fact that your light in the E.R. dimmed and the voltage dropped severly, indicates that the starter get's electricity but is not able to turn the engine. Do you hear a click when you try to start (which means that the solenoide is activated? No click means that the solenoide is stuck. A (little) bang on the starter often solves this problem.

 

[kapnd]

Have you checked the TDC pin in the engine? When it has come out, (for whatever reason) there is a possibility that it blockes the engine while trying to start. The fact that your light in the E.R. dimmed and the voltage dropped severly, indicates that the starter get's electricity but is not able to turn the engine. Do you hear a click when you try to start (which means that the solenoide is activated? No click means that the solenoide is stuck. A (little) bang on the starter often solves this problem.

It’s been a while since I worked on a 555,but I don’t remember there being a TDC pin.
The starter motor is probably capable of shearing it, if indeed there is one, and if it is hydrolocked, it’s not a great idea to keep trying to spin the motor, as thats how rods go through blocks and cranks are bent!

 

[D.Duck44]

Another possibility is that the starter pinion may be jammed in the ring gear, locking everything up. If so, you should be able to free it by turning the engine backwards slightly.

 

[Mr. Blu]

I found this article which maybe helpful.
https://www.passagemaker.com/technical/troubleshooter-when-your-engine-wont-start

 

[C lectric]

Have you checked the TDC pin in the engine? When it has come out, (for whatever reason) there is a possibility that it blockes the engine while trying to start. The fact that your light in the E.R. dimmed and the voltage dropped severly, indicates that the starter get's electricity but is not able to turn the engine. Do you hear a click when you try to start (which means that the solenoide is activated? No click means that the solenoide is stuck. A (little) bang on the starter often solves this problem.

THere is NO TDC pin. THis is different from many engines. The PT or fuel pump does NOT need timing to the crank or camshaft. It is simply a pump. The injector operation and timing is off the camshaft with a rocker and there is a plunger depth adjustment of the injector itself.
NO TDC pin.

 

[River Cruiser]

Another possibility is that the starter pinion may be jammed in the ring gear, locking everything up. If so, you should be able to free it by turning the engine backwards slightly.

I would 2nd this, turning it backwards just a few degrees will free it up if this is the culprit.

 

[Mr. Blu]

THere is NO TDC pin. THis is different from many engines. The PT or fuel pump does NOT need timing to the crank or camshaft. It is simply a pump. The injector operation and timing is off the camshaft with a rocker and there is a plunger depth adjustment of the injector itself.
NO TDC pin.

In that case you don't have to search for it

 

[psneeld]

Any resolution?

 

[Capt. Sea Fever]

Any resolution?

As a newbie this is my biggest mistake thus far.....failing to close the fuel shut off valve and being unlucky as the fuel solenoid locked in an open position. Diesel fuel flooded the entire engine causing a hydrolocked situation.

tilitrider and kapnd suspected the problem as did Nizda. Nizda assumed that I would know to turn the valve off, however, no one ever told me this. Chalk this up to experience.

Anyways, the diesel and oil were removed and changed respectively, and I’m up and running again....some $3k poorer.

In the next month I plan on removing the injector pump and the injectors for cleaning and inspection.

I also plan on getting the engine up to temperature more often!
.......and shutting off the solenoid as well as closing the fuel shut off valve.

Thanks to all for your advice!

Capt.SeaFever

 

[sunchaser]

Is the 555 unique in having this type of fuel leak problem? My curiosity is piqued as to how many of us shut off our fuel systems when leaving the vessel.

 

[twistedtree]

Yes, I'm still really confused about what exactly happened to flood the engine. A stop solenoid that stays open would result in an engine that can't be shut down. But once stopped, fuel isn't going to flood past it. And I have never heard of a need to turn off a fuel supply when shut down to keep an engine from flooding.

I don't doubt it was flooded, but I don't understand the mechanism by which it happened.

 

[Nidza]

I don't like being correct in this case, since my engine is V-504 and both engines (504 and 555), so as V-903 share the operation manual with that caution. I think, as I have said earlier, that if that is the case, it is a design flaw.

I am curious if you have list of the costs with those 3k? Really curious if you had to disassemble the engine!?

Before you install the ball valve in front of electric shut off valve, mind that I do have that (manually controlled one) and it is PITA, I will use that only in emergency (i.e. fire hazard, but in my setup it is not installed in engine room) and I am not closing it anymore in common use. I will explain:

1. You will forget to open the valve more than once and of course, you will be aware of that when the engine stops due to lack of fuel (vacuum made is probably also bad for the fuel system components) and then you have to purge the air to start up the engine. Hopefully, the engine will shut down after you exit tight spaces between slips in port.

2. If you close the valve and remember to open it for the next use, but the boat was on the ramp in between while tilting angles, it can happen that you will have to purge the air again. Mind that I do not have any leak in fuel system and valves are new so I was confused where did the fuel go and how, but it did, and before leaving the ramp in water, I had to purge the air to start the engine. Awkward.

If you already decide to proceed with additional valve route, I highly recommend using electric valve with same control wires for shut-off valve, so you will not start with valve closed ever. They will open and close at the same time, but you will have that additional protection from such case. But, if you leave the key in ON position, it is the same situation as having just shut off valve.

Anyway, it seems to me that this flaw is easily prevented if it is not left for long time with opened shut off valve (manually or electrically) and those shut off valves seems to last a long time.

P.S. Beside manual ball valve I also have fuel bulb (with internal check valve) in line for easier air purging when needed, which I have not done for about two years, since I stopped closing manual ball valve (no problem even after the ramp).

I would like to hear some other smart (smart meaning simple) solutions for easy prevention of such potential problem.

I strongly advise you to find the "Marine diesel operation and maintenance manual" from Cummins for 504/555/903/855/1710 (here is the link to see how does it look like

https://www.ebay.ca/itm/Cummins-504...ash=item2f17d08ba5:g:60YAAOSw5E9aq9bt&vxp=mtr

, but I am sure you can find it from someone in neighborhood with those engines. It it is very valuable, not only for these engines, but for marine diesels in general, because with specific instructions, very detailed explanations are given why to do so, so kind of it can be used as a general learning book about marine diesels (older engines though, but most principles are the same today). Too bad that manuals for new engines are not so detailed considering that we are in "computer era".

 

[C lectric]

Glad you found out what the problem was. I'm sorry you got caught with this. Never considered the shutdown valve as a source. Learned something.

I did have a situation about 8 years ago where the engine would not shut down but a few seals and it is back to normal.

I wonder if that was the initial cause, your valve needed new seals. They were not bad enough to do as mine did, simply refuse to quit, but bad enough to leak fuel.
I suspect also that your tanks and the fuel level must have been above the engine and the valve.

I do shut off my tank outlets unless I am travelling day after day. But in home port those valves are shut.
Maybe I'm just lucky.

Better boating to you.

 

[FF]

"My curiosity is piqued as to how many of us shut off our fuel systems when leaving the vessel."

Very few, although deck operated tank shut off valves are required for USCG on many commercial vessels.

A simple pull handle , a hunk of outboard shift cable and a FUEL, not a water valve for each tank is needed.

Insurance that is easy to afford ,

 

[twistedtree]

I'm still struggling to understand how this led to a flooded engine. Even with no shut off, and with the stop solenoid in the run position, fuel would have to leak past the injection pump, and through the injection nozzles that only open at multiple hundreds PSI. It only seems possible if there were also massive bypass leakage in the injection pump AND the injection nozzles.

 

[Rufus]

As explained in post #7, the 555 uses camshaft operated injectors like the 2-stroke Detroits. Each injector is a mini-pump. No injection pump. If the injector for the cylinder(s) in question was up on a lobe, it's open. That said, I would think the fuel tank level would have to be above the engine injectors...but hard to say without a full picture of the fuel system configuration.

 

[C lectric]

PT System leakage.
There is a difference between the old PT systems used on the 504,555,903 and several other Cummins engines of the day and newer injection systems.

The PT pump is not the typical injection pump seen on many engines and newer Cummins, Deeres, etc. The pump does NOT meter the fuel directly to the injector except by varying, relatively low pressure fed by a common tube and then a gallery in the head. The injectors actually meter the fuel.

The injectors are operated from the camshaft by rocker arms and that is what feeds and closes the fuel off to the cylinder. It's the varying pressure fed by the PT pump that determines how much fuel the injector actually feeds the cylinder.

In newer systems that close off is done by the injector pump for the individual pistons.

Since I'm not an expert I too wondered about it but I'm guessing that if the tank fuel level is above the PT pump then leakage could occur if the shutoff solenoid fails to close 100%. It would only take one injector to cause trouble if it hung up combined with a slightly goofy shut off valve.

My example was that my engine would not shut off untill the valve was re/re'd. If my engine had been down a while, the fuel had been above the engine combined with a flakey valve then maybe I could have a similar problem.


All that said the shutoff valve is mounted on the side of the PT pump, between the heads at the back of the engine. It can be removed and resealed without removing the PT pump. You might get the throttle shaft seal replaced if you go ahead with PT pump removal. That may well be a good move. At least the PT does NOT have to be timed.


Did you have any sign of shutoff problems like mine where the engine continued to run on after supposedly shutting the engine off? Mine did slow somewhat but still ran. Shut 'er down one day properly and the next it wouldn't.

Is it possible the fuel level in the tank is above the engine PT pump?

As for shutting off the fuel at the tanks that would be a good fix. Yes, you will goof once in a while but even that could be kept to a dull roar by a tag over the starting switch and controls. Better than flooding the engine.

I will comment about an explanation from Paul Foulston who was a frequent contributor on Boat diesel and was a real expert on these engines. The engines do need to be run at a good load to keep the injectors clean. He said they are what is called an open injector unlike most injectors with a high pressure feed directly from the pump. They can get packed with carbon he said if not run with a decent load. Don’t need to abuse it just ensure it gets fully up to temp and run with a good load.

My last comment came as I was typing this. Tank venting allowing a pressure buildup in the tank and thus the fuel delivery system. If the vent to the atmosphere is obstructed maybe pressure built up after shutdown. These engines feed a LOT of fuel back to the tank by the return line. That fuel can be very warm, almost hot, and combined with the tank picking up more heat after shutdown from a hot engine maybe that contributed. Take a good look at the tank vent line that it is not plugged, collapsing, kinked or obstructed in some manner. If that happens maybe the pressure build up forced the fuel through. If this is the case it may not need a fuel level above the engine, just a poor vent hose.