Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 14-10-2011, 05:38   #1
Registered User

Join Date: Oct 2009
Location: Pensacola, FL
Boat: Catalina 350
Posts: 2
Yanmar Exhaust Manifold Corrosion

My friend has a 2007 Catalina 387 with a Yanmar 3JH43, 40 HP engine and his exhaust manifold severely corroded at the six o'clock position immediately before the gasket between the manifold and exhaust elbow. The manifold started leaking and he replaced it. Now there is evidence of similar corrosion in the new manifold. We think salt water may be getting into the manifold, maybe through the exhaust elbow and collecting at the corrosion spot. However, we don't know how the water is getting in, if that is what is actually happening. We've check the anti-siphon valve in the raw water discharge hose upstream of the exhaust elbow and it seems to be working fine. Mechanics have been consulted but are unsure what is happening. One suggested modifying the exhaust elbow and raising it somewhat higher above the manifold but space limits the additional height to only a few inches. Another suggested a water lift but there does not seem to be room to install one. Another suggested electrolysis, and, believe it or not, the engine does not have zincs. At least not any that we can find on the engine itself or in the owners manual. The corrosion residue is a somewhat gritty, gummy substance that tastes salty. My friend has talked with Catalina and Yanmar but that was not helpful. We would appreciate any and all comments and suggestions about what is causing the corrosion and how to deal with it. We look forward to your responses. Thanks.
__________________

__________________
Jerry45 is offline   Reply With Quote
Old 14-10-2011, 06:21   #2
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,580
Images: 240
Re: Yanmar Exhaust Manifold Corrosion

Greetings and welcome aboard the CF, Jerry45.
__________________

__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 15-10-2011, 16:25   #3
Eternal Member
 
Chief Engineer's Avatar

Join Date: Aug 2006
Location: North of Baltimore
Boat: Ericson 27 & 18' Herrmann Catboat
Posts: 3,798
Re: Yanmar Exhaust Manifold Corrosion

Is it rust?
__________________
Chief Engineer is offline   Reply With Quote
Old 16-10-2011, 07:23   #4
Registered User

Join Date: Oct 2009
Location: Pensacola, FL
Boat: Catalina 350
Posts: 2
Re: Yanmar Exhaust Manifold Corrosion

Chief,

The corrosion is inside the manifold and almost surely not rust. The corrosion residue is more granular, somewhat like salt.

Jerry
__________________
Jerry45 is offline   Reply With Quote
Old 16-10-2011, 09:26   #5
Senior Cruiser
 
DeepFrz's Avatar

Cruisers Forum Supporter

Join Date: Mar 2006
Location: Winnipeg
Boat: None at this time
Posts: 7,930
Re: Yanmar Exhaust Manifold Corrosion

I would suggest that it is time your friend gets in touch with Yanmar directly.

In the mean time perhaps some pictures of the installation and and some close up pictures of the corrosion might help in us being able to help your friend.
__________________
DeepFrz is offline   Reply With Quote
Old 16-10-2011, 10:34   #6
Registered User
 
Zanshin's Avatar

Join Date: Feb 2007
Location: Caribbean
Boat: Jeanneau 57
Posts: 1,621
Re: Yanmar Exhaust Manifold Corrosion

What you are seeing could be a mixture of scale buildup from the hot water mixed in with rust stains; that is what I had in my exhaust manifold when I replaced it.
__________________
-Zanshin (SV Zanshin)
Zanshin is offline   Reply With Quote
Old 16-10-2011, 10:42   #7
Registered User
 
svcambria's Avatar

Join Date: Jun 2010
Location: Mexico (currently)
Boat: Panda 40 - S/V Cambria
Posts: 573
Re: Yanmar Exhaust Manifold Corrosion

I believe you are correct about the lack of zincs in the engine - at least my 4JH3E doesn't have any.
Possible cause - an electrical ground attached to the engine manifold?

Michael
__________________
svcambria is offline   Reply With Quote
Old 16-10-2011, 11:14   #8
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
Re: Yanmar Exhaust Manifold Corrosion

Jerry,

I would say that one of the flanges are not flat, allowing the salt water to leak while the motor is running, causing it to leak even more over time.


.
Attached Thumbnails
Click image for larger version

Name:	3JH4E_exhaust.jpg
Views:	283
Size:	42.7 KB
ID:	32670   Click image for larger version

Name:	mixertube.JPG
Views:	321
Size:	68.2 KB
ID:	32671  

__________________
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 16-10-2011, 11:22   #9
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 19,363
Re: Yanmar Exhaust Manifold Corrosion

he can have a custom mixing elbow made that is higher and also longer.... so that the exhaust water dumps in the exhaust lower than it does now.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 22-10-2011, 17:32   #10
Registered User

Join Date: Oct 2011
Location: St Pete, FL
Boat: Morgan 36
Posts: 12
Re: Yanmar Exhaust Manifold Corrosion

I have a 4jh2 and just discovered the exact same thing. Ditto on the 6 oclock position. But mine ate so much aluminum from that area that the fresh water water jacket is now exposed(about size of a quarter). Can't afford a new Exhaust mani/heat exchanger so I am having a welder look into patching her up.

We are suspecting the raw water is backing up and sitting there corroding away when engine is turned off. Mixing elbow looks clear though, not sure why salt water is backing up?? Ideas?
__________________
iluvteak is offline   Reply With Quote
Old 22-10-2011, 21:13   #11
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
Re: Yanmar Exhaust Manifold Corrosion

FYI - Can't weld cast aluminum, especially after exposed to saltwater. Cast aluminum is very porous and absorbs contamination.
__________________
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 23-10-2011, 18:07   #12
Registered User

Join Date: Oct 2011
Location: St Pete, FL
Boat: Morgan 36
Posts: 12
Re: Yanmar Exhaust Manifold Corrosion

FYI ... my experience says you can weld cast aluminum. I had the same exhaust mani/heat exchanger welded 7 years ago. Location was the perimeter of the heat exchanger area where the end cap is bolted on. The weld has held up great and saved me $$$!!! Maybe the welder was a magician ... someone in Ft Laud FL.

perhaps the mixing elbow location is a tougher spot due to heat?? Is this what you mean??
__________________
iluvteak is offline   Reply With Quote
Old 23-10-2011, 21:39   #13
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
Re: Yanmar Exhaust Manifold Corrosion

Quote:
Originally Posted by iluvteak View Post
FYI ... my experience says you can weld cast aluminum. I had the same exhaust mani/heat exchanger welded 7 years ago. Location was the perimeter of the heat exchanger area where the end cap is bolted on. The weld has held up great and saved me $$$!!! Maybe the welder was a magician ... someone in Ft Laud FL.

perhaps the mixing elbow location is a tougher spot due to heat?? Is this what you mean??
I had an long time expert try to weld up some winch bases and they sputtered and bubbled like they were plastic.
Attached Thumbnails
Click image for larger version

Name:	DSCN0040.jpg
Views:	174
Size:	398.8 KB
ID:	32882  
__________________
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 29-10-2011, 11:40   #14
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
Re: Yanmar Exhaust Manifold Corrosion

One more thing I might add. Most 3jh/4jh yannys have a bronze exhaust elbow, painted silver. That being next to an aluminum heat exchanger could be part of the problem.

There should be a gasket between the two but if that gets damaged then one might have an electrolysis problem with the aluminum being the anode.
__________________
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 30-10-2011, 18:29   #15
Registered User

Join Date: Oct 2011
Location: St Pete, FL
Boat: Morgan 36
Posts: 12
Re: Yanmar Exhaust Manifold Corrosion

Bronze painted silver. I guess that explains the $400 mixing elbow cost..thanks. I think you've nailed my issue of corrosion in the mani. The gasket was a corroded mess between the mani and elbow. So I guess the corrosion just went nutty and ate mani to pieces - right thru to the water jacket! Welder just told me it is beyond repair, full of holes from 3 oclock to 9 oclock on the mani. $875 new so I am in a pickle. Thanks yanmar nice design team ya got there ....
__________________

__________________
iluvteak is offline   Reply With Quote
Reply

Tags
corrosion, exhaust, 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
If You're Thinking Yanmar, Think Twice Daedalusk Engines and Propulsion Systems 58 08-02-2014 11:26
The Right Way to Run a Diesel off-the-grid Engines and Propulsion Systems 80 09-12-2012 19:06
Exhaust Device Mahaila Engines and Propulsion Systems 5 26-08-2011 13:59
Yanmar OEM Exhaust Elbow or After-Market ? zippy Engines and Propulsion Systems 8 26-07-2011 06:36
Yanmar Instruments Don't Work Yot Libertad General Sailing Forum 5 06-07-2011 06:00



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 16:17.


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.