WOT Alarm on New Engine

[tod]

Folks – I posted this on BoatDiesel and got some feedback but thought that the participants here might have some useful thoughts for me.

I recently had a new (Cummins Reman) QSB 5.9 long block installed in my twin engine 2005 Tiara 3600 (long story). On the way home from the yard, I was following Sbmar break-in advice including occasional short periods of WOT. After a half hour of cruising, I got an ear piercing alarm when I took it up to WOT for about 5-10 seconds. I immediately dropped to cruise (2400 RPM) and the alarm shut off. I repeated the WOT two more times with the same result (alarm after about 5-10 seconds). I have talked to the yard but no conclusive thoughts. Here is a summary of the event and my questions:

The event:

– New longblock QSB 5.9 with approximately 3 hours of run-in by the yard.

– All is well up to cruise RPM

– Ear piercing alarm at WOT that goes away when RPM is dropped down.

– No alarm record shows up on my DieselView display or my Raymarine MFD

– The alarm did not get louder when the engine day hatch was opened.

Other observations/Questions:

– Per my DieselView displays, the new engine (port side) is only coming up to 3010 RPM at WOT whereas the “other” engine (starboard) goes to the spec 3050 RPM.

– Should an engine alarm (low oil, wif, etc.etc) show up on my DieselView?

– Where is the alarm sound coming from? The only speaker at the helm is a 2.5 inch speaker connected to my VHF radio. I haven’t found any piezo buzzer alarms but maybe there is one

– My cabin CO alarms put out a pulse sound (when tested) whereas the event alarm is continuous .

– Is an ear piercing alarm typical of an engine alarm or more typically from a CO or smoke detector?

– What might be causing the new engine to not come up to WOT RPM? Is it possible for the throttle “linkage” to be set up wrong? If so, how can I check it?

It is 100 miles back to the boatyard so I am trying to diagnose/fix this myself before taking it back for the yard to work on it.

Any thoughts are appreciated.

Topic

[Tony Athens]

I’ll be in the shop 8-3 PM-ish Wed..

I see you like Vermillions! Probably one of the best 10 best word wide to eat. Although not that fun to catch..

Tony

[tod]

Tony – Funny you should ask. On Saturday when I looked at the ACs again, I wiggled all of the air connections and tried to rotate them. All were good. However, there was a light black haze on the outside of the fuel cooler. Hmmm? When I was running I took a look at the boost and it was 20 psi which seemed normal.

This is a “new” config AC so it has the condensate drain. I haven’t really looked at it. Will do when I get home.

I might have to drop by Oxnard on Wednesday to get more instructions!!

[tod]

Rob et al – I plan on pulling the AC when I get home and looking inside for anything that might be blocking it when I get home in March. The data seems to support this scenario (clogged AC). It is almost too perfect.

Thx, Tod

[Tony Athens]

Other things to consider——————–No leaking turbo hoses, correct? Aftercooler condensate drain leaking air ( if you have one) ? Got boost numbers?

Tony

[Rob Schepis]

Good stuff Phil.

Tod, you can ask the mechanic all you want as to what he thinks he knows about the aftercoolers but there is only one way to know for sure and to give them the proper servicing that they all need – put them on the bench and follow the protocols on this website and forum, there is no other way.

[Philip]

while a visual inspection MAY show extreme signs of clogging it certainly is possible to clog the AC enough to affect it with result such as your experiencing and visually be ok. The other area of concern (and a BIG one) is the integrity of the AC seals – NO visual will confirm that without disassembling the end caps and removing the core. Only a pressure test will confirm your AC is not leaking. Some creativity and you could pressure test without removal however you still could be clogged on the air side.

To summarize, you have TWO issues your looking at with you AC.
1. Is it clogged on the air side
2. Is it leaking

Out of curiosity what’s you air filter currently look like and service history? Got any close up hi definition pictures of the air filter?

Phil

[tod]

Phil – Thanks for the info on DieselView and IMT. I’ll be checking that out when I get back to the boat in March. Also, I was just thinking that the Acs were off and reinstalled when the block change took place. I will contact the mechanic (100 miles north of me in Victoria, Vancouver Island) and see if he remembers inspecting the AC for clogging. I will pull the AC in March if that remains the #1 likelihood.

[Philip]

Tod

The IMT and low max RPM could certainly be related back to an aftercooler issue. High IMT’s ususally come from AC clogging. The clogged AC could also restrict enough intake charge to limit max rpm.

The diesel view display module does in fact have a buzzer. The lack of history on the display doesn’t surprise me. The IMT drops when you pull back on rpm and the alarm clears. The history function is not dependable as that’s a dream function that never really worked dependably and a perfect example of why diesel views don’t exist today.

Finally when making gph vs rpm charts make sure to not use engine synchronization.

I’ll bet you a six pack that Tony’s advice is spot on with respect to a IMT alarm. I’ll bet you another six pack your boost numbers are different when that alarm is going off..

It’s up to you but a clogged AC is often close to leaking and that can lead to some serious $$$ down the road if ignored. Yes the AC was primarily fresh water but 4 months in salt with no flushing is like years in fresh. It’s time to bench that AC!

Your on the hard and could get that AC serviced (send it to SB if you don’t want to do it yourself) before the season or splash and confirm the high IMT/need to AC service and loose time in the boating season.

Phil

[tod]

Rob – I thought maybe I hadn’t been clear. I have had mechanical engines in the past and the tachs were always kind of a reference. With old (circa 1992) Glendenning synchronizers, to sync them perfectly I had to do it by ear. With this boat, in the synch mode, both engines come up to virtually the exact same rpm and there is no “out of synch” vibration at all. That is why it was so dramatic to me when the port engine only came up to 3010 rpm instead of the “programmed” WOT rpm of 3050 like the other engine.

Thanks for your suggestion on generating RPM vs GPM data. I plan on doing that when I get home in March.

Tod

[tod]

Tony/Rob – I went to the boat yesterday and confirmed my DieselView DOES have a “maniold” page including IMT data. Do you know if the DV has an internal piezo buzzer/alarm? I can’t see one but I need to look more carefully. If that’s what is going on, I’m surprised I don’t see anything in the alarm history.

More on the aftercooler – I bought the AC that is now on the “new” engine in Fall of 2016 from Seaboard. Since that time, I have been in salt water for a total of 4 months and the rest of the time in Lake Washington. The “old” engine always seemed to operate normally (except for oil consumption) and when in “sync” mode, the two engines came up to rpm and tracked each other perfectly. Are you still suspicious of the AC?

Does it seem reasonable that the two “big” symptoms, the alarm (IMT or whatever) and the inability to get to 3050 RPM are unrelated?

I am out of town until March but plan on doing the following when I return based on your and Rob’s suggestions:
– Generate a GPM vs RPM chart for both engines in the “cruise” range.
– Complete more research on the DieselView IMT alarm.
– Monitor IMT during a sea trial.
– Check the rpm using an optical tach and compare to my DieselView values.
– Other diagnostics as suggested by the “experts” including you, Rob and the mechanic (in Canada).

[Tony Athens]

I am 100% sure your base electronics (CM850 ECM –SAE J1939) measures Intake Manifold Temperature & Boost (it’s a combo 4 wire sensor on the top on your engine where all the injector lines hook up.. Easy to “see”.. What I do not know is if “SmartCraft” reads it or displays it on the early engines..

If it was me, I’d pull that aftercooler and service it on the bench. The IMT alarm is set at about 160-165F..

FYI, I am skeptical about the broken ring thing, not that it matters at this point (or maybe it still does?) . If I were to guess , I’d put my money on aftercooler misting that took out the cylinders based on what you have posted. Seen this more than once..

I have also seen this oil consumption issue on more the one Parasail boats to where all the very very fine rope dust particles under the deck made it thru the Walker Airsep filters and took out the cylinder walls in less that 2000 hours.. This issue started showing up in Florida about 2-3 years QSC came out. A lot of head scratching and finger pointing with these.

Tony

[Rob Schepis]

tod wrote:

Rob – This is an electronically controlled engine.

Was there something in my post that would make you think that I am not aware of what engine you have?

[tod]

Tony – I’m listing my answers to your questions:

1) The old motor had 1080 hours on it. I have owned the boat for 4 years and put 600 hours on the engines. Both engines ran fine but the port engine consumed a quart of oil about every 1.5 hours. It ran fine otherwise. I have spent several years trouble-shooting the oil consumption issue (very long story). The most likely answer kept coming back “broken rings” and finally I bit the bullet and had it replaced last Fall.

)2 The LB is a reman unit from Cummins (back east?).

3) The R&R was done by a yard near Victoria, Vancouver Island named Philbrooks Boatyard. They are the best overall yard that I have been in over the last 30 years.

4) RPM vs GPH – The boat is put up for the Winter. I will do this in March when I return back to Seattle.

5) Aftercooler Service History – The boat came with “unclear” AC service history. In Fall of 2016 I did an AC service. The port AC (engine that was replaced) had a core in bad shape and I bought a new assembly from sbmar (I still have the old AC case in my garage that I plan to sell on Craig’s list – My wife is really happy about that).

6) – IMT alarm – Do you think I have one? I didn’t find it on a brief look at my displays. This is a first generation QSB 5.9 and I still have the DieselView displays (I know….). I have queried the DV display alarm history but it says it is empty. The alarm I get is a loud, ear piercing screech and it behaves like you said for an IMT alarm. I have looked pretty hard in/behind my helm for a piezo buzzer but haven’t found one. I also checked my RayMarine chart plotter for alarms but haven’t found anything there.

[tod]

Rob – This is an electronically controlled engine. Before it’s replacement, the “old” port engine came right up to the electronically controlled WOT rpm (3050) exactly like the starboard engine. I have no vibration so I don’t think the prop was damaged during the yard work.

I have had this boat for 4 years and 600 hours but have never had this alarm before (although my WOT operation is normally very limited). I’m not aware of any non-OEM alarms but I’m still looking.

I will go down to the boat tomorrow and get some good pictures of the helm. I’ll post one or more as another reply tomorrow night. Here is a picture of the engine in the installed position as viewed under the engine compartment hatch.

[Tony Athens]

May I ask how many hours on the rebuilt engine before it was rebuilt?

Why did you need a new LB?

Where did the long block come from?

Who did the work?

Post a RPM vs GPH chart like Rob suggested? Be sure you get it in the 2300-2600 RPM range where you mot likely cruise

Status of aftercooler as to proper on the bench service?

Next time you test, find the IMT reading and monitor it while the rpm & GPH climbs.. It will alarm at about 160F and then when you drop the load, with will shut off.

Tony

[Rob Schepis]

I would not worry about that rpm difference, it is ~1.5%, well under the 5% Rated Power Production Tolerance. What I would investigate is your prop loading as to being over propped. (Make a GPH vs RPM Chart).

Is this a new boat to you? Could there be a non-OEM alarm system installed that could be monitoring things such as exhaust temperature or sea water flow?

How about some good pictures of your engines and exhaust from all angles and perspectives and pictures of your helm station and instruments too.

[Author]

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