Onan Generator 9KW - Unexpected Shutdown

[Alex F]

While running for hours all of a sudden my "lights go out" with a sound of BRRrrrr....

My genny doesn't have digital display, so I don't see any codes to give me clues. But, over the years I've learn two major components that are usually the primary candidates for the unexpected shutdown: fuel and/or cooling.

I had no reasons to suspect fuel side being the cause, so I decided to review cooling side first. I was in the area with minimal obstruction like seaweeds, eel grass, jellies, etc. In addition, my scoop-strainers have screens to prevent clogging. However, we never know what can happen. There can always be a plastic bag or something else on the outside of the screen.

So, I check the sea-strainer and see that I have good raw water coming in. I disconnect the hose from the strainer to the water pump and the water is barely coming thru. I blow the hose and it's clean. So, I guess the gravity (the hose is going upwards to reach the pump) prevents good flow and requires pump to circulate generating the flow. My conclusion is that my cooling is fine and now I need to shift my focus to the fuel side.

I look at the racor and the bowl looks crystal clear like I just did the maintenance, but I did it all earlier in late spring.

Before I post my steps to solve the puzzle (it's a weird one too), lets hear your ideas on what would you do next?

 

[Sum Escape]

Any Smartcraft faults in memory? If not, I believe there are blinking lights on the start/stop switch that decode into a cause as well. If you have the same model as I do (MDKBL 4651B) PM me and I can email you a pdf of the manual.

 

[Sum Escape]

From the owners manual:

TROUBLESHOOTING WITH STATUS LAMP​

If a fault shutdown occurs, the amber status lamp onthe control switch will repeatedly blink sets of 3, 4, 5or 7 blinks.​

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One blink indicates shutdown due to high enginetemperature.​

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Two blinks indicate shutdown due to low oilpressure.​

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Three blinks indicate a service fault. Press​

Stop​

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once to cause the two-digit shutdowncode to blink. (Pressing Stop again will stop theblinking.) The two-digit code consists of 1 to 7blinks, a brief pause, and then 1 to 9 blinks. Thefirst set of blinks represents the tens digit andthe second set of blinks the units digit of theshutdown code number. For example, LowVoltage Code No. 13 appears as: blink—​

pause​

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—blink-blink-blink—long pause—repeat​

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Four blinks indicate shutdown due to a failureto start within the time allowed for cranking.​

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Five blinks indicate shutdown due to high levelsof Carbon Monoxide (CO) in the vessel.​

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Seven blinks indicate shutdown due to a lossof raw water flow for engine and exhaust cooling.Blinking continues for five minutes and stops. To restoreblinking press the control switch to STOP(Prime) until the lamp comes on (3 to 4 seconds).Then press STOP (Prime) three times to restoresblinking.​

Note: The last fault logged will blink even though thecondition that caused the shutdown may have been​

corrected.

 

[Alex F]

Thanks for pointing out the blinking codes. I have to say that I use manuals so rarely that often forget to reference them, unless I'm totally stuck. I just checked the manual I have and see the following:

SHUTDOWN CODES
The amber status lamp will blink if the genset
shuts down. It will blink 1, 2, 3, 4 or 7
times, pause, and then repeat the blinking.
The number of blinks is the shutdown
code. Blinking continues for five minutes
and stops. Pressing the control switch to
STOP (Prime) three times restores blinking.

• One blink indicates shutdown due to
high engine temperature.
• Two blinks indicate shutdown due to
low oil pressure.
• Three blinks indicate shutdown requiring
service by trained and experienced
service personnel.
• Four blinks indicate shutdown due to
a failure to start within the time allowed
for cranking.
• Seven blinks indicate shutdown due
to a loss of raw water flow for engine
and exhaust cooling.

I don't remember exact number of blinks but it was many. So, I'd say at least 4 but most likely 7.

I should add that after verifying that the cooling is in good shape I made the attempted to fire up the genny. It started up after cranking for a while, I think it took two attempts and it came back to live. I was relieved for a moment. I gave it couple of minutes before turning on the switches. But as soon as I turned the switches back on the genny shutdown again. This is was the time I shift the focus on the fuel side. I was just praying it's not a fuel pump.

 

[Four Suns]

You assume you have good water flow because you blew in the hose? Is that some sort of magical power to check to see if the raw water impeller lost vanes? Geez... I have to usually take off the water pump cover... I gotta get you to show me this blow thing.

 

[Four Suns]

OK... I don't want you to show me that.

Check the impeller.

 

[Bucit]

.. I gotta get you to show me this blow thing.

And when you're good enough with this blow thing you can take it on the road and start making some money.

 

[mistercomputerman]

Before I post my steps to solve the puzzle (it's a weird one too), lets hear your ideas on what would you do next?

So, you have already solved the problem and you are posting now to see if we are as smart as you are?

OK... I don't want you to show me that.

Check the impeller.

I thought you were asking Alex for a date...

 

[Alex F]

You assume you have good water flow because you blew in the hose? Is that some sort of magical power to check to see if the raw water impeller lost vanes? Geez... I have to usually take off the water pump cover...

You're right, Garry. Checking the impeller crossed my mind as one of the next items to check after I made sure that I had good raw water supply to the impller, but as soon the genny fired up I've verified that I had good discharged. The amount of water coming from exhaust was pretty much what I usually see. This was an indication that the impller is in good shape. Then, the genny shutdown again. BTW, the impller is brand new and there was no reason for it get fried. I've had my genny shutdown about two seasons ago where a pouch of eel grass was stuck on the screen under the boat. The impeller didn't get damaged and worked without a hiccup for the remainder of the season. When I replaced it the following spring (before the new season) it looked as new.

P.S. I took a dive down under the boat and verified that there was zero blockage. I didn't have to do it, b/c I saw that I had good water flow coming from the sea-strainer. But, I just wanted to double check.

... I gotta get you to show me this blow thing.

Only if you come for the flotilla. BTW, I didn't say what I used for blowing. So, don't you run away after seeing the "tool".

So, you have already solved the problem and you are posting now to see if we are as smart as you are?

Do you realy have to ruin a good thread?

No, I just wanted to have good discussion with different ideas going, which most likely help other folks. Was that too much to ask?

 

[Alex F]

And when you're good enough with this blow thing you can take it on the road and start making some money.

Sounds like you're speaking form a first hand experience. I'm fine, don't have a need to enter your territory. So, have at it.

 

[Four Suns]

You need to check the blink codes. Water supply error is usually a plugged water supply (check the 90 degree elbows) or weak/broken impeller (most common). I have chased a water supply error code for a year once and it ended up being that a collapsible hose (no wire reinforcement) was installed on the intake side of the water pump and as the thing warmed up, it would collapse and starve the thing for water. Of course, when the generator shut off, the hose reinflated so I never could see it.

If it is a 2 or 3 blink error, it could be a bad battery/alternator (I had this happen on my 480 DB) and can't maintain 12v while running, fuel system has air getting into it (fuel line leak, fuel hose connection leak, racor seal leak, petcock leak that sucks air in but does not leak fuel, etc. -> have had all of these), or is just low on oil (never had that though).

There... those are my suggestions. My wife will not travel without a generator or toilet... so I replace my impellers all the time.

Skip has much experience with your size generator not running for a year. I'll shoot you his email. I think he replaced a ECM board or something.

 

[Art]

Alex, is your gen running hotter than normal, particularly under load? From your discription discharge appears normal, and the genset does not shutdown until under load. I'm wondering if you have a bad over temp sensor.

Art

 

[CAMELLA]

Alex,
Anytime I had the issues you are referring to was due to a dirty/clogged secondary fuel filter. I change my genset secondary filters 2-3 times a year.

Jon

 

[SR400DB]

So, you have already solved the problem and you are posting now to see if we are as smart as you are?...

This was my reaction as well when I looked at the first post.

 

[Alex F]

You need to check the blink codes. Water supply error is usually a plugged water supply (check the 90 degree elbows) or weak/broken impeller (most common). I have chased a water supply error code for a year once and it ended up being that a collapsible hose (no wire reinforcement) was installed on the intake side of the water pump and as the thing warmed up, it would collapse and starve the thing for water. Of course, when the generator shut off, the hose reinflated so I never could see it.

If it is a 2 or 3 blink error, it could be a bad battery/alternator (I had this happen on my 480 DB) and can't maintain 12v while running, fuel system has air getting into it (fuel line leak, fuel hose connection leak, racor seal leak, petcock leak that sucks air in but does not leak fuel, etc. -> have had all of these), or is just low on oil (never had that though).

There... those are my suggestions. My wife will not travel without a generator or toilet... so I replace my impellers all the time.

Skip has much experience with your size generator not running for a year. I'll shoot you his email. I think he replaced a ECM board or something.

Wow, the collapsing hose is the classic one. Thanks for the tips, Gary.

Alex, is your gen running hotter than normal, particularly under load? From your discription discharge appears normal, and the genset does not shutdown until under load. I'm wondering if you have a bad over temp sensor.

Art

Art, I was thinking that my sensors going bad could have been the issue. But, I'm glad it was not the case.

Alex,
Anytime I had the issues you are referring to was due to a dirty/clogged secondary fuel filter. I change my genset secondary filters 2-3 times a year.

Jon

Jon,

Before taking the fuel filters off, which didn't seem logical after I've reviewed the racor and saw that it looks fine, I decided to switch the tanks. This is what I mentioned being the weird solution to the issue.

Usually I run the genny on the port side so I switched it to the stbd side. On the 2nd attempt the genny fired right up. I let it run with no load for few minutes and then turned the juice up. I let it run for about 20-30min and it acted like nothing happened. Now I'm thinking that there must be something with my port side fuel line feeding the genny. I shut it down and switched to the port side to see if it's really clogged. To my surprise the genny fired right up and ran with the normal load. It's been running for the past two days (not continues, but few hours at the time).

I have no clear and solid explanation other than something must have been stuck blocking the fuel getting thru and when I switched the fuel supply somehow cleared it.

In summary:
- Cooling system appeared to be free of any obstruction.
- Fuel system might have some blockage that was not clearly detected on the original (port side).

Your experience on changing the secondaries few times a year is something I'll keep in mind for the future.

For those that feel that I was being a smart a$$, you clearly misunderstood my intentions. As I mentioned earlier I just wanted to have discussion and hear few good ideas, which in fact we got from number of people.

I hope that my weird solution can help someone out there and those suggestions posted by other folks will help the troubleshooting process. BTW, I've learned something as well. From now on I'll be keeping an eye on the blinking codes and the hose that can potentially collapse.

Thank you all who posted your ideas and shared your experience.

 

[Sea Gull]

The only thing I learned from this thread is that Alex should have checked the fault code.

 

[Ididntdoit]

The only thing I learned from this thread is that Alex should have checked the fault code.

C'Mon - it was like a scooby-doo mystery. I knew old man withers did it......and he would have gotten away with it without those kids an their meddeling dog.......

 

[mistercomputerman]

The only thing I learned from this thread is that Alex should have checked the fault code.

You're a funny MF this morning...

 

[Alex F]

The only thing I learned from this thread is that Alex should have checked the fault code.

Hey, you still learned something.....

Going back to the codes I still can't see that they would have solved my puzzle. I can't say the exact number of blinks there was, but it was quite few, so I have to go with 4-7 blinks assumption here. Reviewing the codes again and we have:

Four blinks - indicate shutdown due to a failureto start within the time allowed for cranking.

Five blinks - indicate shutdown due to high levelsof Carbon Monoxide (CO) in the vessel.

Seven blinks - indicate shutdown due to a lossof raw water flow for engine and exhaust cooling.Blinking continues for five minutes and stops. To restore blinking press the control switch to STOP(Prime) until the lamp comes on (3 to 4 seconds).Then press STOP (Prime) three times to restores blinking.

Note: The last fault logged will blink even though the condition that caused the shutdown may have been
corrected.

None of them are really solving my problem. As we already know I did all necessary steps to handle what could have been applicable to the "seven blinks" code. It did not solve the problem. So, yes knowing the codes is great, but my case was unique one (kind of the one Garry had with the hose) where none of the codes helped. This is why I wanted to share this experience.

 

[Sea Gull]

Alex, you probably had a code 36. (Lots of blinks = 3 blinks then pause, then 6 blinks). Just having a bit of fun at your expense but seriously, I have a spreadsheet I can share with you on genset troubleshooting.