Blue smoke on start up: 6BTA

WilliamR said:

Thanks. Pretty sure I don't have intake air heaters, as it's just a power cord that goes into the block. Not entirely sure where it is located though. the external anti-frost heaters are just the standard Westmarine round ones. It is about -5 centigrade here currently, and it was starting fine in the summer, but smoked a bit on start up - no where near this amount though.

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First off....Cummins engines only have intake air preheaters. I need to re read your start procedure.

Secondly, my engines pretty much don't smoke in the summer and smoke like crazy in the winter when it is cold out...and I am in Texas. They start in less than a second in the Summer....maybe 3-5 seconds in the Winter when it is cold out. Is this just one isolated winter scenario we are talking about a few times that you have started in the winter??? Your engine might be just cold and is a smoker. Some of them smoke more than others. I can tell when mine are cold in the winter, not all cylinders fire initially....hence the white smoke(unburned fuel) and a little rough running. But that they catch within a few seconds and the smoke continually gets better over the first minute. But initially that smoke is BILLOWING.

PS...like TOny said, block heaters are meant to stay on continuously. It does almost nothing to turn it on for 30 minutes prior. Block heaters are very low power meant to transfer heat to the entire engine OVER TIME. 30 minute operation might heat one square inch around the heater(I have no clue how much it heats in 30 minutes but just trying to make the point).

PSS...and this is an edit...the primary benefit of a block heater is to keep your engine room at a constant temperature....therefore no condensation....therefore no rust and a perfectly clean and dry engine room. Their purpose is NOT to preheat an engine. Although if left on continuously your engine will certainly start easier.

Alright...one more question as I am thinking this thru. Can you attribute the amount of smoke and the time for the engine to "catch" on the outside temperature? IOW, is there a direct relationship??? I think what you may be experiencing is simply just smoke on startup that is common with most mechanical diesels in cold(er) weather. You may be chasing a problem that does not exist. Trust me, I did the same thing with my boat the first winter I owned it. Except I have two engines. And one smokes more than the other. So OF COURSE there is a problem with that one engine.....NOT!!!! They are just fine.

In your picture I see the air filter and part of the aftercooler only. Tony is going to want to see more than that. especially the whole aftercooler, injection pump etc.
He will also want to see the starboard side of the engine nice and sharp especially the wiring harness for the preheaters and their solenoid condition.

I know nothing about the Cummins 330 engine. However, we have run a lot of equipment with diesel engines over the years. To me white smoke signifies steam from condensation or possible head gasket problem, black smoke represents unburned fuel, and blue smoke represents oil. Sometimes we have had to replace worn valve stem seals to stop a blue smoke problem. If the engine has oil retained on top of the head it can cause a blue smoke problem. Over time enough oil can seep through to be in the cylinder. Again I know nothing about the Cummins 330 or B series for that matter.

Preheat is manual and we get a big voltage drop when it kicks in and I usually leave it for at least 20 seconds. I also have a block heater I usually put on for 20 mins before start.

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If the voltage drop in on the 12V side that sounds like intake air heater, they draw a lot of current. I dont understand the "manual" operation unless someone bypassed the automatic system. In that case your air heaters are not working properly. As I said above they cycle on and off to continuously heat air until engine gets fully warm and will come on again if temps drop. Look at the intake manifold where the air pipe enters from the aftercooler. Air heaters will have a big wire to a stud located there.
There is no brief "preheat" function.

Baker said:

First off....Cummins engines only have intake air preheaters. I need to re read your start procedure.

Secondly, my engines pretty much don't smoke in the summer and smoke like crazy in the winter when it is cold out...and I am in Texas. They start in less than a second in the Summer....maybe 3-5 seconds in the Winter when it is cold out. Is this just one isolated winter scenario we are talking about a few times that you have started in the winter??? Your engine might be just cold and is a smoker. Some of them smoke more than others. I can tell when mine are cold in the winter, not all cylinders fire initially....hence the white smoke(unburned fuel) and a little rough running. But that they catch within a few seconds and the smoke continually gets better over the first minute. But initially that smoke is BILLOWING.

PS...like Tony said, block heaters are meant to stay on continuously. It does almost nothing to turn it on for 30 minutes prior. Block heaters are very low power meant to transfer heat to the entire engine OVER TIME. 30 minute operation might heat one square inch around the heater(I have no clue how much it heats in 30 minutes but just trying to make the point).

PSS...and this is an edit...the primary benefit of a block heater is to keep your engine room at a constant temperature....therefore no condensation....therefore no rust and a perfectly clean and dry engine room. Their purpose is NOT to preheat an engine. Although if left on continuously your engine will certainly start easier.

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Thanks, but think we are at cross-purposes.

I always switch on pre-heat prior to cranking as per Cummins start up instructions and my earlier message. I thought that answer was referring to the block heater cord.

I get the point of block heaters, but would have thought turning one on 30 mins prior to starting would at least help raise the temperature slightly. I note that it does take the chill off of the engine block to the touch so must do something (compared to leaving it off) even if it doesn't raise the temp significantly. However, there is no way it would produce sufficient heat to keep the engine room free of condensation, even if on 24hrs, although it might well keep the block free of it.

My concern is the amount of smoke at startup that doesn't really clear much for 5 mins at idle in the dock, as per video. It does get slightly better, but I guess I really need to go out and do a sea trial to test it. First winter with the boat so I don't have anything to compare.

Thanks
Bill

I have a 6CTA and I NEVER start it unless I'm going boating. Warming it up at the dock intermittently is pointless. In fact, my understanding is it does more damage. In the spring, I pull the connector for the fuel solenoid, crank the engine until I get an oil pressure indicator, reconnect the fuel solenoid and the engine starts before I can push the starter button all the way in!

I have been known to start the engine to operate the hydraulics but then I put the engine in gear and warm her up under load until normal temps are obtained, then shut her down. She always gets a pre-winter oil change. Spinning the wheel keeps the little barnacles at bay as well.

Smoke is normal. Just don't hang about after starting, bugger off! 8^) if any of you doubt smoking from an old-tech jerk-injection engine should go to Roche Harbour on a Rendezvous Sunday when 100 pampered Grand Banks start up at the same time!

Idling at the dock is a huge mistake in operating procedure.

reread some of the above posts. The engines probably will not warm up at idle. They need a load.

bayview said:

If the voltage drop in on the 12V side that sounds like intake air heater, they draw a lot of current. I dont understand the "manual" operation unless someone bypassed the automatic system. In that case your air heaters are not working properly. As I said above they cycle on and off to continuously heat air until engine gets fully warm and will come on again if temps drop. Look at the intake manifold where the air pipe enters from the aftercooler. Air heaters will have a big wire to a stud located there.
There is no brief "preheat" function.

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Yes automatic system has been bypassed, as in a lot of these boats, so you have better control over the pre-heat once the engine starts. It seems to be working as I see the voltage drop, but is there another way to check? Also how long does the automatic system stay on for?

Bill

WilliamR said:

Yes automatic system has been bypassed, as in a lot of these boats, so you have better control over the pre-heat once the engine starts. It seems to be working as I see the voltage drop, but is there another way to check? Also how long does the automatic system stay on for?

Bill

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I think the heat cycle is terminated about 950RPM. I do think there is a temp associated with that as well but do not remember(somewhere in my cobwebbed brain I want to say 140 degrees but not sure).

You still have not answered which version of 6BTA this is? And I do not know what you mean about "cross purpose". The only heaters that are provided on a Cummins marine engine that are purposed to aid in starting the engine are the intake "grid heaters". ANd they are not all that effective. Most OEM installations have them connected to the ignition switch...meaning that is what activates the control module. Some people(and maybe some OEM installations) have that function assigned to its own switch at the helm. It sounds like that is your case.

And please, and I am not trying to be ugly here, try to keep an open mind here. People are trying to help. Just because you are doing it the "Cummins way" does not necessarily mean it is the best way. Their responsibility to your 17 year old engine ended a very long time ago. There are people on here that are very interested in providing the advice(and maybe even products) to keep your 17 year old engine running for hopefully many more years. Just help them help you. And saying "...per the Cummins procedure" does not help. Let us know exactly what you are doing.

Tony Athens said:

Bill,


1) Current operation.. Do you try and warm your engine at the dock? If so, tell me what your typical protocol is?

2) When you go down to your boat, do you ever start the engine without leaving the dock and taking the boat out on a voyage?




Tony

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Tony,

Can you explain whether it is a bad idea to start the engine at the dock, and what the best protocol is? I like to take my boat out at least once a month, but sometimes cannot and in those rare circumstances, I will start the engines and let them run for 20 mintues (to get up to temp = 159). Same for gen sets, but with those I can put a load on. Is this a bad idea? Is it better to wait until I can take the boat out? Is a month the sweet spot interval (I understand it would be best to take it out every day).


(If it matters, I have QSM 11's with about 2500 hours, and so far, no smoke ever. I typically run at only 1060 rpm, and the engines have burned less than 10,000 gallons each.)


Thanks,
Rick

Baker said:

I think the heat cycle is terminated about 950RPM. I do think there is a temp associated with that as well but do not remember(somewhere in my cobwebbed brain I want to say 140 degrees but not sure).

You still have not answered which version of 6BTA this is? And I do not know what you mean about "cross purpose". The only heaters that are provided on a Cummins marine engine that are purposed to aid in starting the engine are the intake "grid heaters". ANd they are not all that effective. Most OEM installations have them connected to the ignition switch...meaning that is what activates the control module. Some people(and maybe some OEM installations) have that function assigned to its own switch at the helm. It sounds like that is your case.

And please, and I am not trying to be ugly here, try to keep an open mind here. People are trying to help. Just because you are doing it the "Cummins way" does not necessarily mean it is the best way. Their responsibility to your 17 year old engine ended a very long time ago. There are people on here that are very interested in providing the advice(and maybe even products) to keep your 17 year old engine running for hopefully many more years. Just help them help you. And saying "...per the Cummins procedure" does not help. Let us know exactly what you are doing.

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Thanks. Its a standard 2001 built 220hp marine version of the 6BTA with aftercooler, and the exhaust size is standard for the boat. There is the standard Cummins engine pre-heat which is manually activated on my boat, and what I assume is a block heater as its a 120v wired heater in the engine block.

I am very grateful for the input, but there is a lot of different advice here. To be honest, I don't find comments saying "your doing it all wrong" or being patronizing very helpful though. :-(

Thanks so much everyone for all the input. I do appreciate the responses and hopefully its just cold temps and idling without load.

Bill

The manual preheat is not what you think. The preheat function will operate through the ECM in an on /off series of uses until you exceed 1000 rpm or reach a certain engine temp. The switch you have is a Tony Athens mod to turn off the heaters by denying power to the ECM, very handy when you are cruising at low RPM or when your engines are already heated up and you stop for fuel or lunch.

Controlling the Air Heater Circuit on your B & C Series Cummins - Seaboard Marine


Next time you start up leave the manual switch ON, start the engine and watch the heaters kick in and out on your volt meter. Then raise your RPM to over 1000 and you will see this stop. Your switch is an air heater interrupter, not a manual preheater.

John Deere says not to operate without load for more than five minutes. I don't start the engine until beginning casting off lines, and operate from a cold start at no more than 30% power (1.2 gallons versus 4.0 gallons per hour) for at least ten to fifteen minutes underway to reach operating temperature.

The Other Gary said:

The manual preheat is not what you think. The preheat function will operate through the ECM in an on /off series of uses until you exceed 1000 rpm or reach a certain engine temp. The switch you have is a Tony Athens mod to turn off the heaters by denying power to the ECM, very handy when you are cruising at low RPM or when your engines are already heated up and you stop for fuel or lunch.

Controlling the Air Heater Circuit on your B & C Series Cummins - Seaboard Marine


Next time you start up leave the manual switch ON, start the engine and watch the heaters kick in and out on your volt meter. Then raise your RPM to over 1000 and you will see this stop. Your switch is an air heater interrupter, not a manual pre-heater.

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Great, Thanks Ill give that a shot, although doesn't it serve the same function as pre-heat? I.e. the heater heats air in the intake air side facilitating better combustion until the engine has warmed up? The previous owner just said to use it to start then turn it off once the engine had warmed up for a bit, as the auto version used to stay on far longer than needed and ate up the battery unnecessarily.

I tracked down this info I was given with the boat says:

"A pre-heater is installed on the engine. Cummins use an electric intake pre-heater rather than glow plugs because the pre-heater continues to run after the engine has been started. This helps to reduce the white exhaust smoke that is a normal byproduct from a cold diesel engine. Each heating element draws around 100Amps and cycles on/off for the first 20 minutes after a
cold start as long as the engine is under 950 RPM and the coolant temp is less than 160F. A manual pre-heat switch has been fitted on your boat. Turning off the pre-heater reduces the load on the alternator and drive belt, and helps to charge the batteries faster. If it’s a really cold day, you can leave the pre-heater on after starting to help warm up the engine. E.g. if at anchor and you have not had the engine block heater plugged in overnight beforehand."

So, maybe I am not leaving this on long enough after starting in the winter months? How long do folks suggest I leave it on for? I am assuming that it is on when the light is on and the voltage drop is evident on the volt meter.

Lastly, I guess there is no harm leaving the block heater on continuously in the winter.

Thanks
Bill

It seems like there may be some cross talk here. If I'm following correctly, you have two "heater" systems:

1) A block heater that runs off 120VAC. This you turn on 30 min before starting the engine.

2) Intake air pre-heater(s) that operate automatically for start-up and warm up. Your boat has a disable switch for these so you can elect to use them or not. I can't quite tell how you are managing these? On initially then off? Never on at all? On and running automatically all the time?

I don't have direct experience with the 6BTA, but with the limited experience I do have, any modern diesel will start in more like 2-3 seconds, not 5, and definitely not 20. I had a Cat dozer with intake preheat and it would start right up in single digit F weather and not smoke at all. Granted, it's a different engine, but same basic technology.

My first guess would be that you are not utilizing the intake heaters and should be. They are there to aid in cold starts and warm up, and will likely clear up the initial smoking.

But Tony actually knows what he's talking about, so let's see what he thinks.

While I use my (grid)preheaters, I do not think they do much at all. So you might be overthinking it a bit.

IMHO, I do not think you have a problem. It is just cold and your engine smokes. But don't take my word for it. I have just been down this road before. I even replaced the injectors on that engine. Likely a waste of money. It sounds like you have done your due diligence...especially the compression checks. That alone should give you quite a bit of peace of mind....assuming they are in range...which it sounds like they are.

As a side note, I was under the impression that the 220hp 6BT had no aftercooler???...but there is definitely one in your pic. Is this just a significantly derated version of my engine??? I mean there is no need really for an aftercooler to generate the power needed to reach 220? I hope I am not hijacking.

WilliamR said:

Lastly, I guess there is no harm leaving the block heater on continuously in the winter.

Thanks
Bill

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Not only is there no harm, it will do your engine room a lot of good by decreasing the amount of moisture in the engine room. I have a friend in the marine diesel engine business and he says one of your best modifications to a boat is an engine room heater or block heater. It will harm your wallet though as it takes a good amount of power to run them. And finally, they are not terribly reliable as they do burn out when used all the time. Which is why Tony offers a cheaper and more reliable oil pan heater.

Possible valve guide oil leak into cylinders at shutdown. Try running engine to temp. Shut down. 5 / 10 / 15 minutes and see if it smokes.

A "lot" of Cummins operators disconnect the intake heaters because they think it is very hard on the alternator.

Why is it that everyone expects these old-technology diesels not to smoke? They are always going to smoke until the engine reaches normal operating temperature. Even then, if they are not run at a decent cruise power (I don't know what that is, but it's definitely NOT idle power) they are not running at their most efficient and therefore they will smoke a bit. This is the reason that the manufacturers have spent so much money meeting the "tiers" which basically are add-ones to make these engines behave as if it were efficient at all rpms and loads. These Cummins are "no-tier" which to me is what makes them attractive. No electrical doodads to fail in some wild place, simple, straightforward engines.

Diesels do not like to run without a load. Some diesels will NEVER reach their operating temperatures at idle without a load. My old Lehman wouldn't reach normal temps without a load. After you start your engine, you should be ready to put a load on it very quickly, after you have a happy oil pressure. This will heat it up to normal operating temperatures and the smoke will diminish most quickly as the fuel in the cylinder will be burnt at its most advantageous condition.

Block heaters should be left plugged in all the time, it turns the engine block into a nice radiant heater that warms the compartment and generally makes the use of intake heaters redundant (very much imho). It takes quite a lot of time for a block heater to heat all of the coolant in the block so just leave it on.

These engines are not like carbureted gas engines, they do not need to idle for ages to get the Inlet temps up so you can get rid of the choke. These old diesels are much more like modern fuel injected car engines, Start them and go.

I do not know what Tony is thinking about all this blather but I'm sure he will chime in shortly.

Since I posted, I think most of this has been sorted out based on your answers to questions 1,2, & 3………………….This is where you are – Your operation is really bringing on your own issues..

1) Quit trying to warm your boat up at the dock.. Do all your prelims before you start the engine.. Maybe a minute or so MAX to make sure all is right and then get the boat in gear and on it’s way

2) DO NOT START your engine unless you plan on a trip and then follow #1.. I don’t care if it been 6 months. You are washing your cylinders, diluting your oil with fuel and adding measurable amount of waters vapor to your oil, and adding diesel slobber to pool inside your manifold & turbo and making matter worse each time you do this.

3) Remove/disconnect whatever block heater gizmo you have now and install a 250 W Wolverine Oil pan heater on your engine. Once installed, it stays on 24-7-365 when at the dock. If the engine is at ambient temp, it will take 48 hours for the engine block to stabilize and not feel like COLD STEEL went you put your hand on it. When you come back from a trip, plug it in and things will improve 110% that that forward.. Plus your entire boat will benefit from 1500 lbs of thermal mass staying at 15-30 degrees above ambient. You’ll notice that right off when you go down there on a cold morning. Some guys will install 2 x 250 W pads and put one on a simple timer to run at 25-50% duty cycle in really cold temps. The oil pan heaters are the safest solution to keeping things warm as there are NO high current off & on surges like you get with typical coolant immersion heaters—Just soft easy heat.

Remember—NO start-ups without a trip, and no more warm-ups before the trip.

Report back..

One question on this subject. I am not putting in question anything, just want to have a clear understanding of things. Why is it bad to run the diesel engine in idle? What are the effect on the engine?
I am working in the transportation industry, railway and trucking. All our locomotive (diesel) are running a lot of time in idle. In fact they almost never stop running when they are started. When a train arrive in a yard the loco is put in idle and still run in idle sometime for many hours. Same for our trucks, often the truck tractor is running idle for a long time to keep it warm. (while loco diesel engine is maybe very different from a boat one, truck engine are more similar).
So my question, I would like to understand the effect to run an engine in idle for some time.

Thank you to help me improve my knowledge.

Xsbank said:

A "lot" of Cummins operators disconnect the intake heaters because they think it is very hard on the alternator.


I do not know what Tony is thinking about all this blather but I'm sure he will chime in shortly.

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If you don't understand what Tony is saying, at least consider the possibility that he knows what he is talking about. As far as I can tell, he is probably the most knowledgeable person (especially about Cummins) you will find, in or out of their factory. More over, he is very generous in sharing his knowledge. Let's not make derogatory remarks needlessly.

Lou_tribal said:

One question on this subject. I am not putting in question anything, just want to have a clear understanding of things. Why is it bad to run the diesel engine in idle? What are the effect on the engine?
I am working in the transportation industry, railway and trucking. All our locomotive (diesel) are running a lot of time in idle. In fact they almost never stop running when they are started. When a train arrive in a yard the loco is put in idle and still run in idle sometime for many hours. Same for our trucks, often the truck tractor is running idle for a long time to keep it warm. (while loco diesel engine is maybe very different from a boat one, truck engine are more similar).
So my question, I would like to understand the effect to run an engine in idle for some time.

Thank you to help me improve my knowledge.

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Lou

I too have run diesels in the far north, idling for a long time. But, they were always brought up to temperature under load before parked. The radiators were louvered for shut off and the engine cooling system designed for this and maintained at a designed temperature during idling. I'm speaking of minus 40!

A cold start marine engine in Vancouver with no Wolverines or similar is a very different story. MY ER there is maintained at about 50 degrees. Even then it takes about 15 minutes under a moderate cruising load to get all areas up to temperature.

Can't thank Tony enough for showing up here.

sunchaser said:

Can't thank Tony enough for showing up here.

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+1

WilliamR said:

"A pre-heater is installed on the engine. Cummins use an electric intake pre-heater rather than glow plugs because the pre-heater continues to run after the engine has been started. This helps to reduce the white exhaust smoke that is a normal byproduct from a cold diesel engine. Each heating element draws around 100Amps and cycles on/off for the first 20 minutes after a

cold start as long as the engine is under 950 RPM and the coolant temp is less than 160F. A manual pre-heat switch has been fitted on your boat. Turning off the pre-heater reduces the load on the alternator and drive belt, and helps to charge the batteries faster. If it’s a really cold day, you can leave the pre-heater on after starting to help warm up the engine. E.g. if at anchor and you have not had the engine block heater plugged in overnight beforehand."



So, maybe I am not leaving this on long enough after starting in the winter months? How long do folks suggest I leave it on for? I am assuming that it is on when the light is on and the voltage drop is evident on the volt meter.



Lastly, I guess there is no harm leaving the block heater on continuously in the winter.



Thanks

Bill

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Bill, I am learning a lot from this thread, thanks for asking the question. It does appear there was some confusion about the pre-heat. My own understanding (primarily from prior reading of Tony's website) is that there isn't a problem leaving the block heater on 24/7. I don't have one and would like to install one for use 9 months out of the year. Unless there is something specific in your manuals that indicate that it is not OK to leave your specific block here on full time, I would just leave it plugged in all winter.

FWIW, what I know about diesel engines could be recorded on the back of a gum wrapper.

sunchaser said:

Can't thank Tony enough for showing up here.

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+1

Thanks to all, and to Tony for the professional advice. Much obliged and I'll change my operation. Of course if I'd known this already I wouldn't have asked the question!

Most folks have provided thoughtful and helpful input so thanks so much for that. But some seem to have wanted to stretch their ego, and give a sermon. Understandable in an Internet forum, but they might want to consider there is not a lot of point in berating people who ask polite and reasonable questions, and genuinely don't know.

Overall, I have learned some very useful information, and hopefully my issues will resolve with improved engine management techniques. I do want to look after my engine as best I can, fantastic contraption that it is. I come from an aviation background, where the worst thing you can do to an engine is leave it without running it. But that is a different beast entirely, and marine diesels are new to me. The wolverine heating pads seem a good idea, so i'll investigate further (but hope that won't send my dock electric bill through the roof)!

Happy cruising everyone.
Bill

MY I have NEVER disparaged Tony nor have I failed to be respectful. I don't know where you are getting that from. If you read Tony's missives, he is completely capable of defending himself but if he has asked you to do it for him, I apologize to you. I have read all of "Tony's Tips" and I respect his willingness to share his knowledge but if you read MY missives, I am trying to make life easier for boaters who are not as knowledgeable.

My first point, many operators DO DISCONNECT the intake heaters on the Cummins engines. I have, my friend with two diamonds has, plus if you Google it you will find others that have too.

As far as blather, that is my opinion. The misinformation about diesels is rampant and probably every myth or old wife's tale is arrayed across this thread.

Good question about leaving a Diesel engine running - it has a couple of advantages and is a good procedure for industrial diesels. Every time you start an engine, probably the most deterioration is suffers that cycle occurs while it's coming up to temperature. For million-mile engines it makes sense to avoid this. It is not possible for boat owners to come back from a trip and just leave the engine running for all the reasons you can think of but if an engine is to be put to work "shortly" it does make sense. Besides, as pointed out, industrial engines have devices to conserve heat so they don't cool off while running, something you can't do with your recreational diesel.

I remember walking around Paris at night in 1970 and being fascinated by parked Mercedes and Peugeot taxis, locked up and dark but idling in their parking spaces as their operators slept.

Lou, you are missing what I am saying.. I did not say anything about idling your diesel once it gets up to operating temp after RUNNING under loaded conditions ( LIKE GOING ON A TRIP)..

What I am saying is to not run it at an idle ( or even above an idle) when it is not up to full operating temp or trying to warm it up under no load at the dock.. Once the engine is hot from a trip, you can idle all day if you want--but the coolant temp needs to be above 175-ish... As I said, you are causing your own issue with your "protocol" of operation... As to comparing it to Trucks & Locomotives--not even close to apples to apples-- One, they do not have saltwater cooled aftercoolers sending 80F or less air to the combustion chambers, two, they are not 60HP/liter diesels( more like 50% or less than that) , and three, I really doubt they warm they up from DEAD COLD at an idle, and for certain they are not trying to warm them up only to shut them down..



Tony