Yanmar YM coolant leak - 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 forum dedicated to diesel engines and their applicable accessories.


Reply
 
LinkBack Thread Tools
  #1  
Old 06-09-2011
ctlow's Avatar
Junior Member
 
Join Date: Apr 2011
Location: Brockville, Ontario
Posts: 27
Thanks: 5
Thanked 0 Times in 0 Posts
Rep Power: 0
ctlow is on a distinguished road
Yanmar YM coolant leak

I'm starting season 3 with a Yanmar 3YM20, and it leaks coolant. There's always a little under the engine, but a tiny top-up twice a season has seemed plenty.

I changed the coolant the other day, as recommended/required, and as I was removing the pressure/filler-cap on the heat exchanger, loosening hoses/bolts, the leak intensified, and then became a very steady drip for a minute. It was just behind the crankshaft pulley, right on the front of the engine, very localized. I could not find a trail of it dripping from higher up somewhere, and at that point I had just detached the "fresh-water" hose on the front of the engine to do an initial drain.

So, that's weird. The system leaked when I de-pressurized it.

Since re-filling, I ran it for a while and then had to top it up a bit again - normal, I believe - but haven't actually seen any leaking.

Still, this worries me. I have a year to go on the warranty, I think, so am going to look it over one more time and call the installing mechanic, which is a nuisance (5-hour boat-trip away, although of course only 40 minutes by land, and he does do "marina-calls" ...).

I come across various Yanmar coolant leak pages on a web search, but nothing so far definitive that tells me what to do other than call for professional help.

Anyone familiar with this scenario?

Oh, and ... a vane broke a year ago on the impeller, so of course I replaced it and the new one has been fine. I took advice including from the mechanic and it was that it's all okay, but now he says it's not okay and I have to find the vane - which I will do (or he will if I can't). Connection with the coolant leak? They're different sides of the cooling system.

Thank you.

Charles
Reply With Quote Share with Facebook
  #2  
Old 06-09-2011
SVCarolena's Avatar
Pearson 303
 
Join Date: Oct 2007
Location: Washington, DC
Posts: 411
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 7
SVCarolena is on a distinguished road
It is doubtful both problems are connected. My guess is that the vane is in the heat exchanger. just remove the end cap where the raw water side enters. If you don't find it there, then it has to be in the hose between the exhanger and raw water pump. You should fix it, as eventually it could lead to a restriction and overheating.

If the leak is near the front of the engine, it may be the seals on the circulation pump. There should be a weep hole on the bottom behind the pully. Older Yanmar's had problems with plastic fittings for the block drain locations, but I'm guessing yours is new enough to have metal fittings. that said, you may want to make sure those drain petcocks are all closed snugly, just becareful not to overtighten.
Reply With Quote Share with Facebook
  #3  
Old 06-09-2011
Faster's Avatar
Just another Moderator
 
Join Date: Sep 2005
Location: New Westminster, BC
Posts: 14,625
Thanks: 68
Thanked 187 Times in 179 Posts
Rep Power: 10
Faster has a spectacular aura about Faster has a spectacular aura about Faster has a spectacular aura about
Quote:
So, that's weird. The system leaked when I de-pressurized it.
Maybe not so weird... you likely broke a cool-down induced vacuum condition when you opened things up.
__________________
Ron

1984 Fast/Nicholson 345 "FastForward"

".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
Reply With Quote Share with Facebook
  #4  
Old 06-11-2011
ctlow's Avatar
Junior Member
 
Join Date: Apr 2011
Location: Brockville, Ontario
Posts: 27
Thanks: 5
Thanked 0 Times in 0 Posts
Rep Power: 0
ctlow is on a distinguished road
Thank you both. Will have to review with mechanic. Getting underneath my engine would be more than difficult (although I hear they have these things called "mirrors" for places like that ...)
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 2GM Oil leak bclay3 Diesel 8 06-19-2010 09:25 PM
2003 Yanmar, 765 hours - milky oil, overheating, evacuating coolant vpo3 Diesel 2 05-10-2010 11:33 AM
Yanmar coolant replacement Norstar Pacific Seacraft 8 11-11-2009 09:47 AM
Odd coolant leak issue Valiente Gear & Maintenance 12 05-08-2007 12:14 PM
Yanmar oil leak rskaug Gear & Maintenance 0 01-04-2004 07:08 PM


All times are GMT -4. The time now is 07:16 AM.

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

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.