Intercooler accessibility. MS 350/390

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gerilla

Member
Joined
Jan 2, 2017
Messages
16
Location
United States
Vessel Name
Jolly Mon
Vessel Make
Mainship 350/390
I have a 1999 Mainship 350 with twin Yanmar 4LHA-STE turbo diesels... The - STP is a virtually identical engine in the later built 390s.
Has any one out there ever removed the starboard engine aftercooler for cleaning or repair? Seems to be near impossible to access from the side or top! I had a much experienced mechanic give up on removal . Other than moving the engine off of it's mounts or cutting up the salon sole above the engine is there a way to get it done?
 
I feel your pain. The port aftercooler on my 6CTAs is going to be impossible to get to without pulling the engine.
 
I had a set of those the I took the top off and the lower hose. I took dish soap and the garden hose to them. Then I put a small fan blowing through them for 3 days it worked fine and they were clean.
 
Sometimes it is best to just bite the bullet and move the engine. It really is not that big of a job.

pete
 
Sometimes it is best to just bite the bullet and move the engine. It really is not that big of a job.

pete

Agreed. I've hauled and replaced 4 over the years. After few times, it's really not that bad. especially if you've done that specific engine in that specific location once before. You learn all the tricks the first time.

I had a 496 in a boat that took us half as much time to install the second time as it did the first.
 
Following this thread as I plan to service these on my 4LHA-STP's in the near future. Wish I was 40 years younger and 40 lbs. lighter!
 
Moving the engine may be the only way but a major PITA. I am fairly certain that my almost 24 yr old engines (I've owned it 6 hrs) with 2000hrs have never had the
Intercoolers serviced. That being said, I also have to say that the port cooler I recently serviced was in remarkably good condition and I have no reason to think the starboard one is any different. However, everyone reading this will tell me I'm playing with fire by not getting it done asap...and the cautious side of me totally agrees. Come to think of it...those starboard engine mounts will need changing soon .�� Thank you all for the replies.
 
My 6CTAs are 24 years old. I pulled the starboard aftercooler last summer to service it. Once I had it off I tried everything I could to get the core out. I don’t think it was ever serviced. But it looked really good so I pressure tested it and put it back on. It was relatively easy to get off but I could not get it back on the engine without help. Now the port engine has about 4” clearance on the side of the aftercooler so I didn’t even try to take it off. I am going to assume that since the starboard aftercooler was good, the port one is also. If will take pulling the engine to service it. The anodes the PO put in were zinc, here in freshwater, so I went to change the anodes. The bottom one on the port engine broke off. I have to pull the aftercooler to get it out which means I have to pull the engine. I used my inspection camera and didn’t see anything else in the cap besides the old anode piece so it is going to stay unless the engine starts to overheat. Gotta love the boat designer that thought these were good designs…
 
Comodave, I believe we are on the same page with our mutual problem. It has often been said...life is a crap shoot. So I suppose I'll just roll the dice.
 
I spoke with the service training instructor from Mack Boring, Jordan Clore. I had several preventative maintenance questions about the 4LHA STP when I purchased my Pilot 34. I have a pair of these engines in my boat. They are accessible to work on. The single 240 gallon fuel tank is forward of the engines. There is 30 " between the engine and the hull.

I asked Jordan about servicing the After cooler, oil cooler, heat exchanger and reverse gear cooler. The boat is a 2002 and the engines at the time had 850 hours. Not that many hours but a lot of marine age. He told me they recommend using Barnacle buster in cases that there is no over heating or issues with the raw water cooling. Many times the removal of the end covers and pulling the exchanger bundles cause more harm and expense. Kinda the if it isn't broke don't fix it. He did recommend as a preventative maintenance flushing the engines regularly if they are operated in salt water. Followed by full cleaning of the exchangers using the barnacle buster as directed to keep the tubes and water passages clean.

Because I did not know the full history of the maintenance on the engines. I decided to pull all the end plates off the exchangers to inspect them. My main reason for this was when I removed the engine anodes there was nothing there! The boat was always operated in fresh water but still I believe this is a maintenance item that needs to be followed.

The only end cover that I did not remove was the aft after cooler cover. It has an o-ring that seals the exchanger bundle ( air side to water side). I did not want to disturb this. I did remove the forward cover which gave me a good look at the tubes and the interior condition of the exchanger.

After inspecting all of the exchangers I understood why Jordon said flushing and cleaning the exchangers with Barnacle buster will be sufficient as a maintenance preventative item. My exchangers were spotless after 20 years of running (fresh water)

All the end cover gaskets, anodes, orings are all available to purchase and I received them with in a week of ordering them. The complete inspection took me a full day and when doing it I saw several raw water hoses that I thought needed to be replaced. I replaced all the raw water hoses on both engines including the through hull, hard wall hoses. This also included the Tides dripless seal hoses and the rubber seals. I used reinforced clear hose for the Tide seals so I can monitor water flow.

I have the boat in salt water now but it will only be in salt water for about 5 months this year and then will return to fresh water. We boat on Lake Michigan but we are presently doing the Loop. Before I left on the trip I installed Groco flushing adapters. I use two 5 gallon pails filled with fresh water and made up a 1" hose with a ball valve. I use this to flush the engines when ever we are in a harbor for more than a few days. This works good and hopefully will keep the exchangers in good condition for years to come.
 

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I am curious if the floorboards are different in the 350, vs the 390? I had my mechanic go through mine (2001 / 390 / 4LHA-STE’s) in the first year of ownership, and we definitely did not have to move the motor. Now granted, it is a B!tch doing anything on the outsides of either motor. I’ve rebuilt engines, and am pretty handy with a wrench… but I elected to pay someone to work on those engines because of what a PITA this engine space is with twins. (Actually, the whole boat was designed with zero interest in future maintenance or repairs. My frustration with this and other issues is a primary reason for selling). My mechanic cursed and swore Mainship… but it was doable. I also had freshwater flush connections installed. I don’t have any pictures handy, but I am curious the difference if any in the access. While you’re in there, you’ll definitely want to remote the starboard oil filter and install a dip stick on inboard side as well for access issues. :facepalm: The Portside raw water pump is also a ridiculous b!tch as well. Doable… but make sure there are no innocent children within earshot! :rolleyes::lol:

:flowers:
 
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Thanks guys for the detailed input. I think I'm gonna take my chances on that IC. I do keep up with the anodes religiously and have acid flushed the engines raw water side in the past. Frankly, these engines just don't get run very hard with 1800-2000 rpm Cruise speed about 8 kts. True that access to the outboard sides of the engines is difficult . Being of advanced years and over 6 ft tall and over 200lbs convinced me to hire someone to change that port impeller which requires removing the alternator and bracket. I have long arms so the anodes and starboard oil filter are reachable. Other items such as AC and fresh water pumps, holding tank, batteries, shower sump, ACs and generator service is easy . I find it an easy boat to work on...accept for the damn outboard side engine parts . Thanks again for the helpful replies.
 
I feel your pain. Our port outboard side of the port engine is really bad for working. I bought new raw water pumps since the OEM pumps are not very good. The starboard engine is easy. The port engine is a bugger. Formula puta small access hatch from the aft stateroom storage compartment to get to it. But you have to reach around the front of the engine. I bought a larger hatch and will cut the opening larger. Then pay the mechanic to install the new pump. Some things are beyond my scope of work anymore.
 
This is something I've been thinking a lot about. I too have the -STE engines. Mine have over 3000 hours and run great. I've done the Barnacle Buster but still wake up at night worrying about salt-water intrusion to the engines via the intercooler. I'd really like to have a look-see in there and replace gaskets and o-rings.

I had to replace the starboard oil cooler beginning of last season so had to remove it from the engine. Removing the oil cooler and its cradle opens up a surprising amount of room over the top and outboard side of the engine and is not all that difficult or messy to remove. Some large crows-foot wrenches help with the oil in/out fittings.

Getting the air cooler in/out would still be a bear but I think it would be doable.

-Adam
 

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I am curious if the floorboards are different in the 350, vs the 390? I had my mechanic go through mine (2001 / 390 / 4LHA-STE’s) in the first year of ownership, and we definitely did not have to move the motor. Now granted, it is a B!tch doing anything on the outsides of either motor. I’ve rebuilt engines, and am pretty handy with a wrench… but I elected to pay someone to work on those engines because of what a PITA this engine space is with twins. (Actually, the whole boat was designed with zero interest in future maintenance or repairs. My frustration with this and other issues is a primary reason for selling). My mechanic cursed and swore Mainship… but it was doable. I also had freshwater flush connections installed. I don’t have any pictures handy, but I am curious the difference if any in the access. While you’re in there, you’ll definitely want to remote the starboard oil filter and install a dip stick on inboard side as well for access issues. :facepalm: The Portside raw water pump is also a ridiculous b!tch as well. Doable… but make sure there are no innocent children within earshot! :rolleyes::lol:

:flowers:


To my knowledge there is no difference in the floorboard arrangement in a 350 and 390. Also I have a small dip stick on the opposite side from the main dip stick on both STEs ...you should too ...check it kinda hard to see them.
Yes port water pump is a PITA to get too and I hire a mechanic to change it. Only way to change that impeller on that engine and maintain your sanity is pull the alternator and bracket then pull the entire pump. My mechanic can do the job in about 1.5 hrs. Oil filter on starboard engine never been a problem .I place a board over stainer in front of engine and lay across it reaching with left arm. I break it loose with a cheap band type filter wrench use my hand to spin it off and spin on another. Works for me because I am over 6 ft tall with long arms...may not work for you but worth a try.
 
I just had my mechanic put in new raw water pumps on my 6CTAs. The port one is really tough. Formula put a small access hatch from the aft cabin but it was tiny. I cut the bulkhead open for a much larger hatch and the mechanic was able to get to the pump and change it. I went with a new Seaboard Marine SMX pump to replace the OEM Sherwood crappy pump.
 
To my knowledge there is no difference in the floorboard arrangement in a 350 and 390. Also I have a small dip stick on the opposite side from the main dip stick on both STEs ...you should too ...check it kinda hard to see them.
Yes port water pump is a PITA to get too and I hire a mechanic to change it. Only way to change that impeller on that engine and maintain your sanity is pull the alternator and bracket then pull the entire pump. My mechanic can do the job in about 1.5 hrs. Oil filter on starboard engine never been a problem .I place a board over stainer in front of engine and lay across it reaching with left arm. I break it loose with a cheap band type filter wrench use my hand to spin it off and spin on another. Works for me because I am over 6 ft tall with long arms...may not work for you but worth a try.

Yes. That's how I do it (oil filter, or anything on the outboard side of engine). To make things easier, I modified my raw water strainer arrangement to locate the strainers further forward and added quick connect fittings on the strainers. I felt that the quick connects were safe enough given that they are above waterline. I can get the strainers and their mounting plates out in about 15 minutes if I need more room.

This gives more room forward of the engine for getting in there. I can put a plank across the stringers forward of the engine and then go in there head first and put my back up against fuel tank. Getting one hand outboard of engine is easy. Both hands is a little more challenging.

-Adam
 

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Be careful chemically cleaning an after cooler. That said, there are several reasons for removing and dis-assembling an after cooler:

- To clean the air side of oil, debris and soot.
- To clean the water side of scale, rust products and debris
- To pressure check the unit after cleaning
- Greasing the washers and seals for ease of the next removal

For great insight on your particular engine and the importance of cleaning the ACs visit boat diesel or Seaboard marine. Personally I'd be leery of buying a vessel where AC servicing is problematic or the owner had not performed this essential service on a periodic basis.
 
My 6CTAs are 24 years old. I pulled the starboard aftercooler last summer to service it. Once I had it off I tried everything I could to get the core out. I don’t think it was ever serviced. But it looked really good so I pressure tested it and put it back on. It was relatively easy to get off but I could not get it back on the engine without help. Now the port engine has about 4” clearance on the side of the aftercooler so I didn’t even try to take it off. I am going to assume that since the starboard aftercooler was good, the port one is also. If will take pulling the engine to service it. The anodes the PO put in were zinc, here in freshwater, so I went to change the anodes. The bottom one on the port engine broke off. I have to pull the aftercooler to get it out which means I have to pull the engine. I used my inspection camera and didn’t see anything else in the cap besides the old anode piece so it is going to stay unless the engine starts to overheat. Gotta love the boat designer that thought these were good designs…[/QUOTE

I Know the 6cta verry well. The danger with the cooler is the dissimilar metals. You have corrosion in-between the cooler and the housing. That's why you cannot get them apart. The problem is the corrosion at the seal between the air and the seawater side. If you do not take them apart and re seal you will get water on the air side and destroy your engine. Go to SBMAr.com Tony has in-depth information on this subject. The water is under pressure and will be forced into the air side because the seal is compromised due to the corrosion.. It is not if it will fail , but when.

https://www.sbmar.com/articles/cummins-marine-aftercooler-maintenance/

https://www.sbmar.com/articles/testing-a-cummins-marine-aftercooler/

https://www.sbmar.com/articles/aftercooler-disasters/

https://www.sbmar.com/tonys-tips/
 
[/QUOTE] The danger with the cooler is the dissimilar metals. You have corrosion in-between the cooler and the housing. That's why you cannot get them apart. The problem is the corrosion at the seal between the air and the seawater side. If you do not take them apart and re seal you will get water on the air side and destroy your engine.[/QUOTE]

Correct.

Virtually all aftercoolers are built with dissimilar metals. The design and build specs for these marine specific units include a use criteria that assumes a periodic tear down and servicing. The reason chemical cleaning in place isn't necessarily the best choice is that the chemicals used often exacerbate the corrosion issues, do nothing for the air side and ignores the need to change the seals..

As Greg points out, Tony Athens has many articles covering the reasons for removing the ACs for periodic cleaning and pressure checks.
 
I just had my mechanic put in new raw water pumps on my 6CTAs. The port one is really tough. Formula put a small access hatch from the aft cabin but it was tiny. I cut the bulkhead open for a much larger hatch and the mechanic was able to get to the pump and change it. I went with a new Seaboard Marine SMX pump to replace the OEM Sherwood crappy pump.

I did the same upgrade on my previous boat. Never had to touch the pump again. 7 years, except for the impellers of course.

I have sold that boat last spring. I have some extra impellers around if any one is interested.
 

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