Cummins 6CTA Question

[Alex F]

It seems obvious that a $300 valve adjustment is well worth it. However, Russ was talking about 7k in maintenance recommended by Cummins, which, to me, is not worth it without a very good explanation as to why.

You're right. I just wanted to make sure that by general statements like "do it all at home" we don't forget some critical items that is best to address before he takes her home.

 

[floriduramax1]

Good story, Max. It's great that you have intensive experience with diesels. This is exactly what we need in this thread.

I try to simplify the situation and look at it in the following way (from a buyer point of view). I'm buying a great and clean boat with rock solid preferred engines, which passed the mechanical survey very well. I know that those 6CTAs have great reputation. However, I came across number of reports about swallowed valves. One of the reports was on an engine that just passed the survey. So, I have two questions to myself:

1-Why is this happening?
2-How can I avoid this from happening with my engines?

As we clearly see the answers are obvious:
1-Lack of valve lash adjustments during recommended time frame.
2-Spend couple hundred bucks to do the valve adjustments and don't worry about it for another 500-600hrs.

Is it worth to gable $300 insurance vs. $12K possible failure? IMO, it's not worth it, specially if you have recommended certified Cummins shop standing by to do whatever you wish.

In regards to the questions like "....if those engines can't run 150miles.....", I'm positive that even if Russ won't do a single thing (old oil, old fuel filters, old coolant filter, no valve adjustments, etc.), but turns the keys and drives the boat she will get him home in the following 6hrs. The only point is here, is this the best approach? Obviously not.

Thanks F. I agree and appreciate your position. I would think they would have already beat the seat out if they were going to. If he can indeed get them adjusted for 300 bucks then by all means, that would be a "no brainer". But to go forward with 7k worth of work then take off for home would not be my first choice...just sayin

 

[SR400DB]

Russ

Thanks for the email. I have done the following:

oil changes (every 100 hours, genset, mains and trans); includes new filters (except on trans, simple metal screen just requires a cleaning)

heat exchanger/aftercooler cleaning; every two years

zincs 3X a year

valve lash adjustment, every 500 hours (I am just over 1100 now) (I have been told Cummins has recently changed to 600 hour increments)

new fuel filters every 100 hours

air cleaners; every 2-3 years (I am probably going to start doing these with the oil changes annually)

raw water impellers every year

new belts (mains and genset) every other year

coolant flush every 4-5 years (I have used the test strips every year since year 3 and changed the filter accordingly).

I have done all of the maintenance except the valve adjustments. Check out www.sbmar.com. Tony is easy to reach and will help with advise if you want to do some on your own. I am curious about why they want to change the thermostats? Mine are original 160 degree units. I did have the valve adjustment done about a year ago with a Cummins Tech, we went over all of the maintenance items and the thermostats were not mentioned. I do run my boat all year and make sure the engines are put under a load every 2 -3 weeks at a minimum.

That's all I can think of right now.

 

[floriduramax1]

It seems obvious that a $300 valve adjustment is well worth it. However, Russ was talking about 7k in maintenance recommended by Cummins, which, to me, is not worth it without a very good explanation as to why.

You're right. I just wanted to make sure that by general statements like "do it all at home" we don't forget some critical items that is best to address before he takes her home.

It looks like you guys covered my thoughts while I was typing and paying my Snap On truck account...lol

 

[alnav]

Russ, if you haven't already explored this, recommend you go to https://quickserve.cummins.com, sign-up and enter your engine serial numbers. There are a couple of manuals, including the current maintenance interval recommendtions and parts catalog for free and you will also get a tailored page with outstanding service bulletins and recalls, if any, on your engines. More detailed service manuals are available on-line through a paid subscription to the site which will give you detailed procedures for each maintenance activity if you want to try and do them yourself. It's a little pricy at $100/yr but well worth it IMO for at least your first year. Up to 5 ESN's can be accessed with a subscription so it's possible to go in with a buddy or two and reduce the cost for each.

 

[Russ Calasant]

Russ, if you haven't already explored this, recommend you go to https://quickserve.cummins.com, sign-up and enter your engine serial numbers. There are a couple of manuals, including the current maintenance interval recommendtions and parts catalog for free and you will also get a tailored page with outstanding service bulletins and recalls, if any, on your engines. More detailed service manuals are available on-line through a paid subscription to the site which will give you detailed procedures for each maintenance activity if you want to try and do them yourself. It's a little pricy at $100/yr but well worth it IMO for at least your first year. Up to 5 ESN's can be
accessed with a subscription so it's possible to go in with a buddy or two and reduce the cost for each.

I have, thank you

 

[Russ Calasant]

Russ

Thanks for the email. I have done the following:

oil changes (every 100 hours, genset, mains and trans); includes new filters (except on trans, simple metal screen just requires a cleaning)

heat exchanger/aftercooler cleaning; every two years

zincs 3X a year

valve lash adjustment, every 500 hours (I am just over 1100 now) (I have been told Cummins has recently changed to 600 hour increments)

new fuel filters every 100 hours

air cleaners; every 2-3 years (I am probably going to start doing these with the oil changes annually)

raw water impellers every year

new belts (mains and genset) every other year

coolant flush every 4-5 years (I have used the test strips every year since year 3 and changed the filter accordingly).

I have done all of the maintenance except the valve adjustments. Check out www.sbmar.com. Tony is easy to reach and will help with advise if you want to do some on your own. I am curious about why they want to change the thermostats? Mine are original 160 degree units. I did have the valve adjustment done about a year ago with a Cummins Tech, we went over all of the maintenance items and the thermostats were not mentioned. I do run my boat all year and make sure the engines are put under a load every 2 -3 weeks at a minimum.

That's all I can think of right now.[/QU


Wow, that's great and very helpful, thank you. He mentioned the thermostats because he thought the temp may have been a little on the cool side and that current thinking may be that 170 is recommended but said he would check. They were rock solid at 160.
I looked at that invoice again and noticed it was $7900 not $7000, that's crazy.

 

[Russ Calasant]

The other thing that is hard to put a price on is peace of mind. If it makes you feel better then get the stuff done. These internet forums bring every flaw to the surface and magnify them 1000x. For all the trouble tree engine out there we read about the few failures. If we read everything out there there Porsche would never had sold a single Boxster (IMS failure), Benz with trans issues, Cats with soft blocks, etc.

Sure it's a risk not to have the work done but then again there are countless engines running fine without the adjustment, either
due to clueless owners, ignorance, misinformed....

I wouldn't look to run it for a season but the 150 miles to get it home and to a local certified Cummins tech is not an unreasonable risk to take.

There is absolute truth to this and is usually unsaid. There is a careful balance leaning on the side of caution that I prefer to walk and that is the line I am trying to define. Thank you. There is a wealth of good knowledge, intention and ideas being thrown around in this thread and it's all been very helpful.

 

[Russ Calasant]

It looks like you guys covered my thoughts while I was typing and paying my Snap On truck account...lol

Good stuff! Thanks for your input

 

[SR400DB]

Wow, that's great and very helpful, thank you. He mentioned the thermostats because he thought the temp may have been a little on the cool side and that current thinking may be that 170 is recommended but said he would check. They were rock solid at 160.
I looked at that invoice again and noticed it was $7900 not $7000, that's crazy.

I saw that as well. It seems high to me, but I am far from an authority on going rates. I know the first valve adjustment was $1100. The second was just under $900 (same tech, knew my boat and my maintenance history). It only took about 2.5 hours for both engines (not including travel). I would definitely get this done prior to the long trip. My boat runs at 160 (since new) degrees as well. I have heard various things about changing to the higher degree units, but have not done so (and probably will not).

 

[floriduramax1]

Good stuff! Thanks for your input

You are welcome. Most of the time I don't comment on these things because of how quickly they can turn ugly. I have been through this scenario more than once. We hired 2 Captains to bring the "big girl" up from Mexico and these guys have never seen her before! The one thing we had going for us was the relationship with the Cat guy. The gamble to bring her up the east coast to Jacksonville and down the St Johns to Sanford to have the work done paid off. We have found many things that I would not have wanted mechanics in Mexico to mess with...lol Good luck with whatever you decide!

 

[fwebster]

Living down here in the practical world where the rubber meets the road, I am curious as to what the surveyor saw.......other than his mechanics needing work in the winter.....that caused him to recommend all the cooler/heat exchanger cleaning. Absent some indication of a problem, those items don't seem critical enough to do before a 150 mile trip.

Surveyors are not perfect.........ask the guy that magic question: WHY?

 

[BRBSTA]

Run it if you are concerned have the valves adjusted when they are changing the oil

Evualate the rest when you get home

PS not all cummins techs have the same hourly rate

Enjoy the ride

 

[Jaws]

Russ,
Although I'm no expert on these motors, I have run the same for four seasons so at least I have some experience. They are stout motors and I would not be too concerned about the valve lash adjustment. It is recommended at 600 hrs and I had it done at 500. It only made a slight performance difference in my case. The Cummins 6CTA are not that sensitive to lash adjustment. See boatdiesel.com. My concern would be the cooling side, impellers and after cooler. If you have access to a borscope, close the seacocks (remember to open them later) and take out the lower zinc anodes in the after coolers. Check the core bottom with the borscope if you are concerned. But if you want my honest opinion, just keep an eye on those temperature gauges, making sure that the dash and on-engine ones agree. My gauges are nailed on 160 degrees where they should be and so are yours. The thermostats, if original, are 160 degree units, not 180. Make sure your oil is up near the upper mark but not over and run these motors at around 2200-2275 rpm, watching your temp gauges. Have a good trip back and have your Cummins service done at your convenience. Put a pair of Wolverine pan heaters on at some point as well. They are a modest but useful investment. Good luck.
James

 

[pilotman53]

I now have Cummins 6CTA also, Sunday at the marina when i started them they smoked for a few minutes, seemed excessive to me, kinda light blue white color, seems it would be a probablem in a crowded marina. Any thoughts, thanks richard lewis

 

[SeaNile]

I now have Cummins 6CTA also, Sunday at the marina when i started them they smoked for a few minutes, seemed excessive to me, kinda light blue white color, seems it would be a probablem in a crowded marina. Any thoughts, thanks richard lewis

Generally that is a sign of oil burning. Could be a valve seat, oil on the cylinder walls, etc. Although not a good sign, many engines will smoke like this at start up.

 

[Morgan Jane]

Bill, I was going to stay quite, but man what a post :smt101.



I wonder where you get such statistic? Perhaps Russ should have clarified that the service he is looking to do would be performed by Certified Cummins shop, regardless in NJ or at homeport.



Unfortunately, this statement is conflicting with what we all know as preventive maintenance, which minimizes the risk of anything (or at least major components) breaking. We don't wait for engine/genny overheat alarm to go off before changing impellers, right?



If I recall (Russ, correct me if I'm wrong), the 600hrs service was recommended by the surveyor. So, the question is not whether it should be done or not. The question is WHERE to do it, in NJ or take her home and do it in CT?

Alex, I believe you have missed my point completely. Not sure why? And I am not just talking off the top of my head. I have been repairing and rebuilding Cars and Boats my entire life. Unless no preventive maintenance has been done on the boat and there are some glaring issues that need to be attended to, there is no way in the world that I would have a certified anyone at anything come and do a 600 hr. tear down, valve adjustment or whatever, and then just get in the boat and drive it home. And even if I did all the work my self I wouldn't do it. And especially if someone else came and did it, I wouldn't do it. Again, if it needs something fixed, then it needs to be fixed. That is a no brainer. But to have someone come down and just tears things apart that are not really broken or worn out on a new ownership boat before a big trip. Wouldn't do it. I would check out every single Impellar and put in new ones if any teeth are broken, fix any leaks, make sure all liquids are topped off and away I would go. You have to assume that the boat got to where it is under its own power and wasn't towed there. So it must have been alright at that point. and you have to assume that the person who is selling the boat knows that a Sea Trial is part of the process. And if you decide to buy the boat and you do a Sea Trial and all goes well, why take anymore chances tearing the engine apart to find any other issues is the point? I brought my first boat back from FLA. that way and fixed things along the way that needed repair and none of those things would have been caught in a 600 hr. service anyway. My statistic refers specifically to experiences I have had when I or others have repaired things. Sometimes bolts don't get torqued properly and eventually come loose, sometimes bolts are left off. For instance, I have completely torn some assembly down and put everything back together and when I am done I have a bolt left over. You think if a tech ended up with bolt left over at the end he is going to take more than a few minutes to put the bolt where it goes. Might? Might not? My point was to not chance it when the boat is not in your home waters.

Bill

Alex, do you do you own engine service? or do you have someone else do you engine work?

 

[carterchapman]

Generally that is a sign of oil burning. Could be a valve seat, oil on the cylinder walls, etc. Although not a good sign, many engines will smoke like this at start up.

SeaNile,

I have been researching these motors for a possible 420/460 purchase. That doesn't make me an expert in any way, but, don't these engines have an electric intake heater, which if not working, causes those symptoms...

 

[SeaNile]

SeaNile,

I have been researching these motors for a possible 420/460 purchase. That doesn't make me an expert in any way, but, don't these engines have an electric intake heater, which if not working, causes those symptoms...

Absolutely could be. I was thinking of my diesel days with mechanical engines and no block heaters. Block heaters greatly reduce the amount of start up smoke as do any type of pre heating device.

If the intake heater is not working then the smoke will be present. The other question is...does this happen on both engines or just one. If it is both, then it is unlikely they have the same non working part.

Diesel engines have come a long way in the past several years with reducing smoke and burning cleaner. I've found that pretty much all diesel engines will smoke a bit at start up, especially on a cold day or on high humidity days when first started up.

The best place for accurate diesel info, especially on Cummins is boatdiesel.com and Tony Athens. That guy is the man. He'll even just talk you through a few things on the phone, help you diagnose issues by video clips, pictures, etc. In return I bought every possible part for my engines that I could through him at seaboard marine in CA.

 

[Alex F]

I now have Cummins 6CTA also, Sunday at the marina when i started them they smoked for a few minutes, seemed excessive to me, kinda light blue white color, seems it would be a probablem in a crowded marina. Any thoughts, thanks richard lewis

When you start your engines look at the volt meter needles. If they stay at 13.5-14v without movement while the engines are cold this would indicate an issue with your grid heaters. The normal operation is for the grid heaters to cycle every 20-30 seconds. When they kick in the voltage should drop to 10-11v. This should happen for about 10+min (depending on the outside temps) until the engines will reach normal temps.