yanmar engine gasket corrosion - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance > Engines > Diesel
 Not a Member? 

Diesel This is a new forum dedicated to diesel engines and their applicable accessories.


Reply
 
LinkBack Thread Tools
  #1  
Old 05-30-2012
Junior Member
 
Join Date: May 2012
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
zilla is on a distinguished road
yanmar engine gasket corrosion

I have a sea water cooled Yanmar 3GM30, installed as new 3 years ago in a wooden yacht and only 120 hrs engine run time. I replaced 2 of the 3 anodes 7 months ago (I've only just discovered the third anode hidden behind the fuel filter). The previous anodes were about half corroded.
A few months ago I noticed some white powdery substance around the plastic screw that drains the engine block near the fuel pump and a little around the head gasket. I wiped it off and recently checked it again. It is worse and appears on about 4 inches on one side of the head gasket near the fuel pump, about 3 inches on the opposite side of the head gasket, around the engine block drain plug again and also around about 1 inch of the water pump gasket. I'm concerned that the corrosion may be inside the engine and not just the outside where the gasket (presumably a copper alloy of some sort) meets moist air. I'm guessing the problem is galvanic corrosion from contact with sea water in the engine block but I thought the anodes were supposed to stop that.
The negative from the battery to the engine block is always connected but the positive from the battery to the starter motor is always isolated when not in use.
Has anyone seen a similar problem and found a solution?
Reply With Quote Share with Facebook
  #2  
Old 05-30-2012
casey1999's Avatar
Senior Member
 
Join Date: Oct 2010
Location: HI
Posts: 2,775
Thanks: 3
Thanked 14 Times in 14 Posts
Rep Power: 4
casey1999 is on a distinguished road
Re: yanmar engine gasket corrosion

I am not quite sure what the problem might be. I have a sea water cooled Yanmar 3gmd that is 30 years old and do not see this problem. I did change my 3 engine zincs about a year ago. When I changed the zincs, there was nothing left of the one that was replaced. I imagine the engine had been used for many years with no zincs (the zinc plugs were very difficult to remove- rusted in place). The engine had been used so while I will change the zincs, I am not sure how effective they are as the engine did not seem to be corroded, but it is cheap insurance to have good zincs for whatever they are worth.

I think you may have either aluminum poultice corrosioin or maybe the white stuff is salt left when a small sea water leak evaporates of the water and salt is left.

http://www.qualitymarineservices.net...corrosion.html

Was the engine a rebuilt one? Looks like maybe the gaskets are leaking (salt water) due to improper torques of the bolts. I think the engine may be older than 3 years as I think Yanmar now sells only fresh water cooled engines with a salt water heat exchanger.

Looks like the engine is a minimum of 7 years old:
http://shop.torresen.com/marine_dies...entname=engine

Last edited by casey1999; 05-30-2012 at 02:48 PM.
Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Yanmar Saildrive Corrosion ColinD General Discussion (sailing related) 15 10-05-2013 09:42 PM
Yanmar 3YM30 - Blown Head Gasket tomperanteau Diesel 10 02-29-2012 10:23 PM
Yanmar SB8 Gasket Parts Numbers snakyjake Diesel 1 01-31-2011 01:54 PM
What oil for Yanmar engine trantor12020 Gear & Maintenance 26 04-21-2008 03:50 PM
gasket for flush cockpit engine hatch williamtaylor Gear & Maintenance 1 08-15-2004 02:39 PM


All times are GMT -4. The time now is 10:11 PM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012