Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 17-09-2009, 14:19   #1
Registered User

Join Date: Sep 2009
Location: Sharon, MA
Boat: Jeanneau 43DS 2005 'Amoreena'
Posts: 7
Send a message via Skype™ to Tidetracker
Yanmar 4JH3-TE Overheating at Full Load

Hi, all...

Well, this one is a mystery. I've always done my own diesel maintenence and repair, but this is the first Yanmar I've owned, and I'm stumped... so is a diesel mechanic friend of mine.

It started in the spring, on our first outing. Normally, if I want to 'get somewhere', my cruising speed is usually 2800 or 2900 RPM, giving me 8.25 knots. This is the fifth season with this boat, and the engine has 475 hours on it. I've taken this boat all the way to mid-coastal Maine three times, and have spent many hours cruising the waters outside of Narragansett Bay, RI.

The trouble started the first time out. After about ten minutes at our usual cruising speed, the hi temp alarm started to sound (our panel only has the idiot light and sounder, no gauge). We shut it down, checked out the usual suspects, and restarted it ten minutes later. No problems, as long as we kept the RPM down to 1500-1800 RPM.... but running it back up to 'normal' RPM's caused the alarm to go off again.

Normal water flow out the exhaust... normal coolant level in the expansion tank. I opened up the water pump">raw water pump, but the impeller looked pristine, no broken, torn, or missing vanes.

So, I gave a new temp sensor a try. No luck... same problem.

This time, I figured that the thermostat might be stuck closed... so I replaced it (surprisingly expensive!). Still no luck, same symptoms.

A friend ran across something unusual... a report that Yanmar raw water impellers sometimes have had poor bonding between the rubber and the metal hub, and could slip under high load.... so I replaced the impeller with a brand new one (turned out to be VERY hard, even with a proper puller, because of limited clearances). The old impeller looked like it had come straight out of the factory, with no evidence of slipping on the hub (although it would have been hard to see, regardless).

We thought this had cured it, and the following weekend, sailed down to Jamestown for an overnight. The next morning, we had to rush back, so we throttled up to 'normal' cruising speed... and the alarm went off again.

At this point, after consulting several different articles and forums, I've got it down to two possibilities:

1) The heat exchanger is clogged with marine growth... not enough to impede water flow, but enough to reduce the thermal transfer characteristics, by coating interior surfaces with slime. There's a lot of marine growth in our area.

2) Possible problems due to electrolysis (more on that in a bit).

The first problem is a bit of a dilemma. Unlike the previous engines I've owned, which had a separate heat exchanger sitting on a clamp at the rear of the engine, and easy to remove, the Yanmar is much different. It appears that the raw water circulates through a heat exchanger which is actually part of the exhaust manifold, and then to an engine oil cooler (much like a regular heat exchanger, except it's virtually buried underneath the turbo) before exiting via the exhaust elbow. The engine oil heat exchanger is similar to heat exchangers I've known, with the usual tube structure, that could be rodded out, if growth was clogging it. I have no clue, however, how to clean the other heat exchanger, which looks like it's buried in the exhaust manifold.

Has anyone ever had to clean theirs out? How about the oil cooler... anyone ever remove it for cleaning?

Now, about electrolysis. I usually haul my boat out every other year.... in the intervening years, I keep it in the water. The bottom paint is good for two seasons, and it makes commissioning a lot easier, in the spring, when it's in the water. Usually, my zincs are pristine, even after a full year.... but I hired a diver a few months ago, to make sure that my engine raw water intake wasn't clogged, and he told me my zincs were completely gone... maybe the 'winter slip' I was in had a lot of leakage from adjacent boats... in any event, I'm told that the engine oil cooler is very sensitive to electrolysis... and I'm, also told it's extremely expensive to replace (which I'm not surprised about.. I couldn't believe that a simple thermostat, from a Yanmar dealer, was $69!) I haven't hauled the boat yet, figuring that another month wouldn't hurt anything (with regard to the lack of zincs).

So, that's the situation. Anyone familiar with any of this? I'd appreciate comments and suggestions.
__________________

__________________
Tidetracker is offline   Reply With Quote
Old 17-09-2009, 15:28   #2
Senior Cruiser

Cruisers Forum Supporter

Join Date: Mar 2006
Location: Nevada City. CA
Boat: Sceptre 41
Posts: 3,745
Images: 9
Wow sounds complicated. I take it you have checked the exhaust elbow -- not likely since water is coming out -- but worth checking. In looking at Caulders book another option would be an airlock in the fresh water circuit, There is a pretty good section on it in the "Boatowner's Mechanical and Electrical Manual"
__________________

__________________
Fair Winds,

Charlie

Between us there was, as I have already said somewhere, the bond of the sea. Besides holding our hearts together through long periods of separation, it had the effect of making us tolerant of each other's yarns -- and even convictions. Heart of Darkness
Joseph Conrad
Charlie is offline   Reply With Quote
Old 17-09-2009, 17:40   #3
Senior Cruiser
 
bstreep's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: San Antonio, TX/Port Aransas, TX
Boat: 1990 Macintosh 47, "Merlin"
Posts: 2,274
A couple of thoughts, since I have the same engine - and mine overheats when the seawater is above 85 and the rpms are over 3000 - but just to alarm (100 on the gauge).

It's turbocharged, right? The turbo winding up correctly? Have you ever cleaned the turbo? The exhaust side can get sooted up.

What is your coolant mixture? It should be no MORE than 50% coolant. The lower the amount of coolant, the better the heat exchange.

Any chance the engine is getting O2 starved? Got plenty of airflow into the engine compartment?

You are correct about the heat exchanger. I swear it takes a partial disassembly...
__________________
Bill Streep
San Antonio/Port Aransas, TX
bstreep is offline   Reply With Quote
Old 17-09-2009, 17:51   #4
Eternal Member
 
Chief Engineer's Avatar

Join Date: Aug 2006
Location: North of Baltimore
Boat: Ericson 27 & 18' Herrmann Catboat
Posts: 3,798
Since you rely on audio alarms, go out and buy a Raytek handheld infrared heat sensor.

It is invaluable to me for troubleshooting overheating problem, heat exchanger problems, bad injectors.......plus it will give you water temperature and tell you how hot your beverage is.....also good for checking air conditionin units
__________________
Chief Engineer is offline   Reply With Quote
Old 29-09-2009, 14:33   #5
Registered User

Join Date: Dec 2008
Location: Indianapolis, Indiana
Boat: Passport 456 Center Cockpit
Posts: 7
Have you changed your prop? I just bought a boat with the same engine and a similar problem came up during the sea trial. The engine only had 450 hours on it and appeared to be in very good condition. No blue or black smoke. Coolant seemed good. Oil good. It was overheating at 2800 rpms. The max rpm's under load is supposed to be 3,800 I believe. Turned out to be a prop pitch problem. The Max prop was over-pitched. After we moved it down one setting, we took the boat back out and ran it WOT with no more overheating problem. May lose some bite at slower speeds with the flatter pitch, but that's a trade off I can live with for an engine that reaches its design rpms under load.
__________________
Cletus1219 is offline   Reply With Quote
Old 29-09-2009, 16:44   #6
Senior Cruiser
 
senormechanico's Avatar

Cruisers Forum Supporter

Join Date: Aug 2003
Boat: Dragonfly 1000 trimaran
Posts: 5,821
How big are the barnacles on the prop?
Of course, there shouldn't be any, but a fouled propeller is the first thing I'd check.

Steve B.
__________________
senormechanico is offline   Reply With Quote
Old 29-09-2009, 17:48   #7
Senior Cruiser
 
delmarrey's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Now in Blaine, WA
Boat: Modified Choate 40
Posts: 10,702
Images: 122
Quote:
Originally Posted by Tidetracker View Post
1) The heat exchanger is clogged with marine growth... not enough to impede water flow, but enough to reduce the thermal transfer characteristics, by coating interior surfaces with slime. There's a lot of marine growth in our area.
I hope you have a sea-strainer inline before the pump inlet.

The heat exchanger is right above the exhaust with an end cap on each end and two allen cap bolts holding them in place. An EZ job to remove to inspect the core, which can be pulled out. But you will need new gaskets to replace the caps. You should carry spare gaskets anyway.
__________________
Faithful are the Wounds of a Friend, but the Kisses of the Enemy are Deceitful! ........
A nation of sheep breeds a government of wolves!

Unprepared boaters, end up as floatsum!.......
delmarrey is offline   Reply With Quote
Old 29-09-2009, 18:22   #8
Registered User

Join Date: Jul 2008
Posts: 81
had a similar problem with 3GM30

My Yanmar 3GM 30 had a problem overheating in warm water, In the spare parts box were a huge number of used cooling parts, and a couple of new ones. I replaced the thermostats, and I had already replaced the impeller and seals in the water pump.

I had read about people replacing engines and not replacing the through hull and causing a problem. I had also heard of a major manufacturer installing through hulls that were just a little too small for the installed yanmar.

When I pulled the boat out of the water I thought the through hull looked kinda small, and I knew that it was the one part that I could not easily replace in the water, so I replaced it when I painted the bottom. My plan was to install an oversized hose to the strainer and an oversized strainer, but the problem went away with just a through hull, I haven't had a problem in years.
Good luck with your Yanmar.
__________________
decktapper is offline   Reply With Quote
Old 29-09-2009, 18:59   #9
Registered User

Join Date: Dec 2008
Location: Indianapolis, Indiana
Boat: Passport 456 Center Cockpit
Posts: 7
While you're checking for barnacles on the prop, might check to see if the thru hull is clogged too.
__________________
Cletus1219 is offline   Reply With Quote
Old 29-09-2009, 19:07   #10
Registered User
 
r.furborough's Avatar

Join Date: Oct 2008
Location: Norfolk, VA
Boat: Freedom 32 (Hoyt)
Posts: 223
Check the water injection elbow on the exhaust elbow, they are a common source of this type of overheat problem. Here is a link to my report to my owners group website that includes pictures.

FreedomYachts.org • View topic - Overheating Yanmar - Troubleshooting

The replacement of the elbow cured the overheat, subsequently I replace the whole elbow and riser, Yanmar recommends replacement every 500 hours.
__________________
------------------------------------------------
the memories of a man in his old age, are the dreams of a man in his prime
Pink Floyd - 'Free Four'
r.furborough is offline   Reply With Quote
Old 08-10-2009, 08:56   #11
Registered User

Join Date: Sep 2009
Location: Sharon, MA
Boat: Jeanneau 43DS 2005 'Amoreena'
Posts: 7
Send a message via Skype™ to Tidetracker
Quote:
Originally Posted by r.furborough View Post
The replacement of the elbow cured the overheat, subsequently I replace the whole elbow and riser, Yanmar recommends replacement every 500 hours.
Hmmmm.. I've never seen this anywhere.

In any event, thanks for all the suggestions. I hadn't checked the 90 degree fitting, but will do so.

On the freedomyachts.org website, there was some discussion of cleaning out the raw water system by running muriatic acid through it, which had already been suggested to me by some folks at the marina. I didn't do it, wanted to get some additional opinions first.

As for the prop pitch: I run an AutoProp, so pitch isn't the issue (it's self-pitching) but it is likely to be fairly fouled, since the boat has been in the water for two years now. I'll be hauling it out in another 3-4 weeks, and obviously will clean the bottom and the prop before next season.
__________________
Tidetracker is offline   Reply With Quote
Old 08-10-2009, 09:02   #12
Senior Cruiser
 
bstreep's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: San Antonio, TX/Port Aransas, TX
Boat: 1990 Macintosh 47, "Merlin"
Posts: 2,274
Quote:
Originally Posted by Tidetracker View Post
As for the prop pitch: I run an AutoProp, so pitch isn't the issue (it's self-pitching) but it is likely to be fairly fouled, since the boat has been in the water for two years now. I'll be hauling it out in another 3-4 weeks, and obviously will clean the bottom and the prop before next season.
OK, back up the bus...

You mean to tell me you have a prop that hasn't been cleaned? Well, now we know what your problem is, don't we.
__________________
Bill Streep
San Antonio/Port Aransas, TX
bstreep is offline   Reply With Quote
Old 08-10-2009, 15:14   #13
Eternal Member
 
Chief Engineer's Avatar

Join Date: Aug 2006
Location: North of Baltimore
Boat: Ericson 27 & 18' Herrmann Catboat
Posts: 3,798
Two years!!!! Your lucky it hasn't grown roots!!! (kidding). In this part of the Chesapeake I have seen props foul with barnacles in less than two MONTHS!!!
__________________
Chief Engineer is offline   Reply With Quote
Old 08-10-2009, 20:09   #14
Senior Cruiser
 
senormechanico's Avatar

Cruisers Forum Supporter

Join Date: Aug 2003
Boat: Dragonfly 1000 trimaran
Posts: 5,821
When we were anchored in Zihuatanejo one December, we grew 1/2 inch barnacles on our stern anchor rode in one month.

The chain on the bow anchor was in similar condition.

When we got ready to leave, Janet raised it about a foot at a time while I used a steel bristled brush on the first 30 feet of chain.

After that, it was clean as it had laid on the bottom.

It took almost a half hour to remove the growth from the stern rode.

I'm glad we had anchored on the South side of the bay where the water was clean and warm.

Steve B.
__________________
senormechanico is offline   Reply With Quote
Old 10-10-2009, 12:09   #15
Senior Cruiser
 
delmarrey's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Now in Blaine, WA
Boat: Modified Choate 40
Posts: 10,702
Images: 122
Back to the over heating......

I would just like to thanks all the participants! This has been a eye opener.
I recently bought a Yanmar 3JH4E and my existing thru-hull is a 3/4". Well I see that the inlet on the motor is a 1".
I would think Yanmar would supply more detailed installation instructions. I had to beg the dealer just to get copies of the parts manual.

SOoo, it seems I need to install a larger thru-hull. Well that's just fine cause that brought to my attention that the exhaust is now on the opposite side, which would be directed right over my existing thru-hull and sea strainer, making it hard to access.

Soo, now I get to drill another hole in the bottom of the boat and glass up the old one. I'm sure I would have discovered this sooner or later but this helps to pre-plan and eliminate another surprise.
..................................._/)
__________________

__________________
Faithful are the Wounds of a Friend, but the Kisses of the Enemy are Deceitful! ........
A nation of sheep breeds a government of wolves!

Unprepared boaters, end up as floatsum!.......
delmarrey is offline   Reply With Quote
Reply

Tags
overheating, yanmar

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Yanmar 3YM30 Overheating Talbot Engines and Propulsion Systems 9 25-02-2010 05:51
Load on Halyards Triton318 Deck hardware: Rigging, Sails & Hoisting 2 24-02-2009 18:06
Overheating Yanmar? Zephyrus General Sailing Forum 4 05-10-2008 15:25
3gm30 Yanmar full of hose water.... Dave in Eugene General Sailing Forum 14 12-02-2008 20:15
Yanmar overheating seagypsywoman Construction, Maintenance & Refit 42 20-09-2006 14:41



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 06:38.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.