Volvo engine random shutdowns

[allardiced]

Hi,

On our 2021 R-29CB (Volvo D4-320 diesel engine), for the past couple months, we've been having a problem with our engine shutting down while we are running. Its not completely random, as we have noticed some patterns, but sometimes it is. What happens is that the 10A circuit breaker on the engine trips, and therefore the engine computer goes offline, at which point the Volvo panel at the helm shows an error ["Communication Failure - Communication fault with Engine Management System"] and the engine has shut itself down. Here is the pattern we have noticed - when we are running at low speeds (below 1400RPM) we have never seen this issue. When we accelerate to higher speeds (3300RPM), it sometimes will happen around 1600-2000RPM without anything else going on. When we are running at 1600RPM or higher, this will reliably happen when we use the coffee maker or microwave. The parallel switch is in the OFF position, so it surprises me that the house circuit will have any impact on the operation of the engine, but that is what we see.

Until this morning, we have avoided this issue by running the generator, as our experience has been that as long as we run the generator, this issue does not manifest. Historically we rarely used the generator because the house bank was enough for us as we ended most days at a marina. This morning, after anchoring out, we started the generator, and then got underway after raising anchor. After a few minutes, when the engine was warm, we accelerated to our fast cruise speed ... and the engine cut out. This is the first time it happened while the generator was active and engaged (it stayed on throughout). We raised the hatch, reset the breaker, cycled the Volvo ignition, and everything came back online as normal (which is our typical procedure - we are getting good at this). However, the fact that this happened this morning has me worried because we thought we were aware of the conditions which trigger this issue and thereby could manage the boat to avoid this happening while underway. Apparently not!

What I think happened this morning is that the generator was charging the batteries (our new Victron battery monitor showed ~50Amps going into the house bank), and perhaps with that "load" in the sytem, somehow the issue was triggered. Strange, but I don't have a better explanation.

We discussed this with our dealer and several technicians, and no luck in solving it thus far. We checked the wiring and the batteries (the ones we could get to) and things seemed ok. The load tests seemed to indicate the batteries were good but we could not isolate all the individual house batteries nor could we get to the engine battery. We replaced the breaker, but same behavior. The engine has always started fine and seems to hold a charge. Same with the house bank. We have tested the thruster/generator battery and that checks out fine.

Some additional information - the very first time this happened, we had anchored out two nights in a row, which was rare for us and therefore we failed to pay close attentiont to the battery levels that morning. The engine started fine, but we were getting low engine voltage warnings on the Volvo & Garmin systems sporadically throughout the day. After the first warning, I tried to start the generator but the generator battery was too low and didn't start. We ran successfully most of the day and I figured the alternator would put some charge into the batteries and that we would be able to get to our destination. Well, late in the day, we had our first engine shutdown. We didn't realize it at the time but it was the Volvo circuit breaker on the engine, and it likely happened when we made an afternoon tea using the Keurig machine. We got towed back to marina and started the process of working with mechanics to figure out what was/is going on. We have not yet confirmed why this is happening and haven't successfully resolved it. Wanted to see if the folks at the factory or anyone else has seen this and has any advice. Planning to change the batteries just to rule out that possibility but would prefer to have a good explanation of why this happening and how to confirm the failure mechanism, just to know that we are solving the real issue! Is this happening to anyone else?

Regards,
-Darryl

 

[Gin]

That one's way beyond my skill and experience level. But it's a great writeup about the problem, Darryl.
One question, not that I know whether it would bear on anything. Have you tested the alternator and regulator?

Gini

 

[scross]

Darryl, what is the inverter status during these symptoms? Are you just turning the inverter on when using A/C appliances? Is the inverter on when the generator is on?
We’ve never used A/C appliances underway or mooring away from shore power. The inverter just sucks way too many amps out of the house batteries. But we don’t have a generator.

PS: Same questions for air conditioning if you have it. Are you running air conditioning underway? If so it the generator always running when using the air conditioning either underway of when mooring/anchoring?

I’m just wondering if you are getting the house bank under the voltage the ACRs need to work and end up not charging the other battery banks.

 

[RichBirk]

I will be watching this thread closely as it sounds like a problem we recently had.
What I have learned is the new common rail injection systems are very sensitive to voltage drop and air in the fuel system.
It was suggested to me that I should load test the start batteries. I had 2 Life Line group 31 start batteries, 3 years old. (To access the start battery, I cut a hole in the floor under the rear refrigerator.) Result of load test: fail...
This was a surprise to me as the engine would always start well but then die soon after. I also went over the entire fuel supply system checking for vacuum air leaks, including fuel filter seals.
I now have 2 new Oddessy group 31 dual purpose start batteries and a third new thruster battery.
50 hours later, problem has not reoccurred, but I still do not have a definitive explanation of what the problem was. In my opinion,, 2 start batteries are better than one and annual load testing is a good idea.
Feel free to PM me if you want to discuss further. A phone conversation works best for me as I am a very slow typist and computers don't like me....

 

[YukonRon]

My first response to this would be to remove all the house batteries and load test each one individually. It sounds to me like you have a bad battery in the house bank. Even one bad cell can drag the whole bank down.
It does sound like a low voltage issue shutting down the engine computer.
You don't seem to have trouble starting the engine, so I'm guessing the alternator is charging the start battery directly and that seems to be working. However, at low RPMs the alternator is not putting out full power to keep up with the load that's dragging it down.
When your running high RPMs the alternator is putting out, then you turn the coffee maker or microwave on; the inverter puts a huge load on the weak house batteries, and the alternator is trying to keep the house bank charged through the ACR; and the voltage dips; triggering the engine alarm.
If your house and generator batteries are both running down, it could be, as mentioned, the ACRs are not kicking in during charging due to the low battery voltage not triggering them.
Lots of speculation on my part not seeing your system, but hopefully some educated guesses that may help.
Good luck with that, intermittent electrical issues are never fun, but you have made a good start by analyzing the symptoms.

 

[allardiced]

Quick update to provide more details and answer questions thus far ...

- we did have a marine tech from AquaYacht check the alternator and seemed to be fine

- inverter is basically always on and seems to work fine; we have 4x 110AH batteries in our house bank so a decent sized (for us) which has supported the use of coffee maker or microwave while running (or at anchor) for over 9 months on the Loop without issue; we generally only use the AC when on shore power at a marina, never from the inverter (probably trips a circuit breaker), and extremely seldom from the generator. In fact we rarely used the generator before this issue.

- in terms of the actual failure, we have to reset the circuit breaker on the engine block, so its not a computer alarm (to my knowledge, as the circuit breaker isn't likely that smart); so my assumption is that there is a voltage/amp spike on the engine circuit which exceeds the threshold of that breaker and causes it to physically trip; once tripped, the engine is offline and the volvo system responds accordingly with various alarms.

- just did a test with the generator off and parallel switch ON and saw the same behavior - engine cuts out at higher RPMs when using the coffee maker. saw a voltage sag down to 12.4v or so on the battery monitor and 100amp draw from the house bank, but I believe that is normal when under load (will do some more tests at rest and confirm).

- tried to load test the batteries but so difficult to get to them, especially without my tools for cutting holes in the floor under the cockpit frig! planning a boat project to get better access to the batteries; thus far only able to load test a couple house bank batteries, but couldn't get to the others (especially the engine battery) so haven't yet load tested it.

- will look for the ACR indicator lights just to verify but I think those are working normally.

- to add more to the puzzle, we found out over the last couple days that even with the generator ON and *no loads*, the engine will shut down at speeds of 1400RPM and above, when the house bank is below 90% soc. We have to run below 1400RPM and keep the generator on until the house bank gets charged back up to 90~95% SOC (at which point the charger starts tapering the amps put into the house bank). Then everything is fine and we can run fast again, but at lower SOC in the house bank, engine cut outs still occur in spite of the generator engaged and no loads 🙁 Getting a taste of cruising at "trawler speeds" the past couple mornings. Normally we enjoy a bit faster cruising speed in our R29CB!

Thank you Rich for your info. Like you suggested, generally the bets are on a bad engine battery. Planning to purchase replacement engine & thruster starter batteries, and in the process of getting to the engine battery will take out all the house batteries and load test them and verify all connections. Fingers crossed. Planning to do The Crossing from Carabelle in a couple days and then tackle these battery project(s) in the next week or two.

Regards,
-Darryl

 

[RichBirk]

Darryl,
Sounds like you may have a different and possibly more complex problem. My boat was rewired for a lithium house bank and I don't have a gen set.

Note that the house and start batteries are mounted on a plastic sled that is screwed down to the floor. Providing you can reach and remove all screws, this tray will slide back for easy access to all batteries. If you think you're going to want to load test or replace batteries Tis would be a good time to cut a hole under the refrigerator for future access. I find it easier to pull the fridge than to slide the battery tray back. Heavy.

Be aware, the floor under the fridge is a fiberglass honeycomb material 1and a half inch thick. You may want to finish the edges of this hole with something to avoid glass slivers in your arm.

I sincerely hope you find a really simple solution to your problem so you can avoid the above.
Please keep us posted

Rich

 

[Automaticman865]

Hi just a quick late night read Was there any mention of the fuel/fuel line, perhaps a blockage….
Good luck
Stuart

 

[scgck]

Very interesting issue.
Although we have a different engine in our 2021 R27 OB the charging system principles are basically the same. Can you monitor the voltage delivered to the engine when this failure occurs ?
It seems that if you could isolate the house bank from the alternator while under way ( disconnect the ACR between the engine battery and the house bank ) for troubleshooting purposes you may determine in which system the problem may be.
Just a thought.
Chris

 

[YukonRon]

When I pulled all my batteries out for my lithium upgrade, I made some mods to the battery mounting for easier future access. This is what I did, since I was re-cabling with heavier cables anyways for the lithium upgrade:
-turned the platform around end-for-end so the engine battery is easily accessible instead of hidden behind the house bank.
-screwed guide blocks with overhanging hold-down lips at the far end of the compartment to hold the platform down with no screws. Platform is screwed down at the stern-end only, where it is accessable.
-added two runner strips of "Snow Slider" plastic under the platform to help it slide. Add a little silicone lube.
-added a webbing strap pull handle onto the front of the platform.
-installed heavy gauge bus bars for positive and negative house connections to eliminate excess cabling on battery posts.
Now I can easily remove the front platform screws and pull the whole platform part way out, remove the engine battery cables, and then pull the platform all the way out exposing all the batteries.
Extra work up front to be sure, but worth it to me for long term imrovement in maintenance access.

 

[RichBirk]

When I pulled all my batteries out for my lithium upgrade, I made some mods to the battery mounting for easier future access. This is what I did, since I was re-cabling with heavier cables anyways for the lithium upgrade:
-turned the platform around end-for-end so the engine battery is easily accessible instead of hidden behind the house bank.
-screwed guide blocks with overhanging hold-down lips at the far end of the compartment to hold the platform down with no screws. Platform is screwed down at the stern-end only, where it is accessable.
-added two runner strips of "Snow Slider" plastic under the platform to help it slide. Add a little silicone lube.
-added a webbing strap pull handle onto the front of the platform.
-installed heavy gauge bus bars for positive and negative house connections to eliminate excess cabling on battery posts.
Now I can easily remove the front platform screws and pull the whole platform part way out, remove the engine battery cables, and then pull the platform all the way out exposing all the batteries.
Extra work up front to be sure, but worth it to me for long term imrovement in maintenance access.

Smart

 

[TugnuttyR29]

When I pulled all my batteries out for my lithium upgrade, I made some mods to the battery mounting for easier future access. This is what I did, since I was re-cabling with heavier cables anyways for the lithium upgrade:
-turned the platform around end-for-end so the engine battery is easily accessible instead of hidden behind the house bank.
-screwed guide blocks with overhanging hold-down lips at the far end of the compartment to hold the platform down with no screws. Platform is screwed down at the stern-end only, where it is accessable.
-added two runner strips of "Snow Slider" plastic under the platform to help it slide. Add a little silicone lube.
-added a webbing strap pull handle onto the front of the platform.
-installed heavy gauge bus bars for positive and negative house connections to eliminate excess cabling on battery posts.
Now I can easily remove the front platform screws and pull the whole platform part way out, remove the engine battery cables, and then pull the platform all the way out exposing all the batteries.
Extra work up front to be sure, but worth it to me for long term imrovement in maintenance access.

Great upgrade to access your batteries, going forward. Would you happen to have any pictures of your screwed guide blocks and runner strips of "Snow glider"?

 

[YukonRon]

Great upgrade to access your batteries, going forward. Would you happen to have any pictures of your screwed guide blocks and runner strips of "Snow glider"?

Sorry, I don't have pictures. I couldn't find starboard locally so I used heavy plastic cutting board material cut into strips.
By stacking wider strips on top of narrower ones I formed the lip that holds the platform down.
A guide is scewed to the floor on each side, angled, so that the platfom slides into a wide opening at the stern end. As the battery platform is pushed forward, the guide spacing gets narrower to centre the platform and lock it into place.
An extra strip is screwed across the forward bulkhead about 3/4" off the floor, so that the lip of the leading edge of the platform slides underneath to help hold it down.
Now that the forward end is locked into place, I use a couple screws at the stern end corners to keep it in place.
The plastic runners are strips cut from the "Crazy Carpet" snow sliders that kids use to toboggan down snow hills. It's a thin (about 1/16 to 18") very slippery plastic sheet.
I hope that makes some sense.

 

[jnbucknam]

We have experienced almost identical behavior on our 2012 C28. The engine is a Volvo D4-270 which was installed 2 years ago and has only 113 hours on it. Until last weekend we had no problems with the engine shutting down. But after a 2-hour cruise at our normal 10 knots, followed by an overnight at a mooring ball in a quiet Maine harbor, we set out to return home the next morning. We did our usual startup checklist with no unusual symptoms appearing, then motored out of the harbor at about 5 knots, 700 rpm. At the mouth of the harbor, we eased the throttle forward and at 1000 rpm the engine just quit, with the same message ["Communication Failure - Communication fault with Engine Management System"] appearing on our Volvo display. We could not restart the engine - nothing happened with the usual turn of the key. A call to our Volvo mechanic, who had installed the engine, led to the suggestion to reset the circuit breaker on the engine, which we did, and that allowed us to restart the engine. We cautiously cruised a few laps around the harbor at 700 rpm before trying to ease the throttle forward again. When we did, once again the engine quit at about 1000 rpm, with the same error code. We left the boat on a rental mooring until our mechanic can get to it to attempt a diagnosis.

I was hoping this thread would indicate a cause and solution to this problem. Has anyone figured out the problem?