Engine coolant level - 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? 
  #1  
Old 11-02-2013
Junior Member
 
Join Date: Sep 2011
Posts: 17
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
saillessinseattle is on a distinguished road
Engine coolant level

In a modern yanmar engine with 75 hours, I observed what looked like low level of coolant. In the plastic expansion tank (not sure of proper terminology), it was right on the mark for low. The boatyard doing the 50h service said this was normal. Now when I look at the boat with the engine cold, that plastic tank is empty. The engine is not overheating or anything (yet?).

Questions: is this normal, at least as it gets cooler? I am worried I might be loosing coolant (no leaks in sight around the engine) or at least that I can no longer tell the level at all (it could have a gallon left or a quart and I wouldn't know?). Thanks!
Reply With Quote Quick reply to this message Share with Facebook
  #2  
Old 11-02-2013
Senior Member
 
Join Date: Oct 2011
Location: Naniamo B.C.
Posts: 2,085
Thanks: 2
Thanked 37 Times in 37 Posts
Rep Power: 4
Capt Len is on a distinguished road
Re: Engine coolant level

At the very least you should fill the tank to where you can see the level at all times.Then keep a close watch. Slow loss into the salt side of heat ex is hard to detect unless all other possibilities are eliminated. Is hot water heater in the circuit?
Reply With Quote Quick reply to this message Share with Facebook
  #3  
Old 11-02-2013
jackdale's Avatar
Senior Member
 
Join Date: Dec 2008
Location: Calgary, AB, Canada
Posts: 8,966
Thanks: 27
Thanked 54 Times in 51 Posts
Rep Power: 7
jackdale will become famous soon enough
Re: Engine coolant level

When the engine is cold the coolant should be at or just above the low mark. You can add a 50/50 mix of coolant and water to the expansion tank.

You might also open up the cap on the heater exchanger WHILE THE ENGINE IS COLD and check the level. If you cannot see into the exchanger, you can use your finger to check. You should feel coolant before you feel the top of the coil inside the exchanger.
__________________
__________________
ISPA Yachtmaster Offshore Instructor Evaluator
Sail Canada Advanced Cruising Instructor
IYT Yachtmaster Coastal Instructor
ASA 201, 203, 204, 205, 206, 214
As I sail, I praise God, and care not. (Luke Foxe)
Reply With Quote Quick reply to this message Share with Facebook
  #4  
Old 11-03-2013
gamayun's Avatar
Senior Member
 
Join Date: Aug 2009
Location: San Francisco
Posts: 479
Thanks: 14
Thanked 22 Times in 22 Posts
Rep Power: 6
gamayun is on a distinguished road
Re: Engine coolant level

This has been a constant source of weirdness for me because the manual doesn't specifically state at which level the normal cold engine should be. I have a Yanmar 3GM30F with about 2600 hours. I keep forgetting to look at that tank when it has been running to see if it is filling up to the high mark. I just keep the level of 50:50 coolant at the low mark. Everything seems to be fine. This is one of those many things I plan to inquire about when I take a diesel class one of these days. Also, my manual says you should be able to touch all the engine parts by hand and if anything is too hot, it should be checked out further.
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

s/v Kynntana
Freedom 38
Reply With Quote Quick reply to this message Share with Facebook
  #5  
Old 11-03-2013
ASA and PSIA Instructor
 
Join Date: Apr 2000
Posts: 3,497
Thanks: 7
Thanked 19 Times in 19 Posts
Rep Power: 15
sailingfool will become famous soon enough
Re: Engine coolant level

Be sure to only top up with the right coolant, which is whatever coolant is in the engine. Start with whether its green or red...better to the exact brand and product.
__________________
Certified...in several regards...
Reply With Quote Quick reply to this message Share with Facebook
  #6  
Old 11-11-2013
Junior Member
 
Join Date: Sep 2011
Posts: 17
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
saillessinseattle is on a distinguished road
Yes, water heater is in the circuit, would that affect the symptoms or possible problems? I can't tell the kind of coolant from the color, I would assume red because that's what the yanmar manual calls for, but I did not have a chance to open the heat exchanger yet.
Reply With Quote Quick reply to this message Share with Facebook
  #7  
Old 11-11-2013
JimsCAL's Avatar
Senior Member
 
Join Date: May 2007
Location: Glen Cove, NY
Posts: 2,499
Thanks: 2
Thanked 46 Times in 42 Posts
Rep Power: 8
JimsCAL is on a distinguished road
Re: Engine coolant level

My general take on this (cars too) is keep the coolant level at about the low mark when cold. Don't really worry about the level when hot.
Reply With Quote Quick reply to this message Share with Facebook
  #8  
Old 11-12-2013
Member
 
Join Date: Sep 2010
Location: Boston area
Posts: 92
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 5
mbsl98 is on a distinguished road
Re: Engine coolant level

Quote:
Originally Posted by saillessinseattle View Post
In a modern yanmar engine with 75 hours, I observed what looked like low level of coolant. In the plastic expansion tank (not sure of proper terminology), it was right on the mark for low. The boatyard doing the 50h service said this was normal. Now when I look at the boat with the engine cold, that plastic tank is empty. The engine is not overheating or anything (yet?).

Questions: is this normal, at least as it gets cooler? I am worried I might be loosing coolant (no leaks in sight around the engine) or at least that I can no longer tell the level at all (it could have a gallon left or a quart and I wouldn't know?). Thanks!
-----------------------
I think of this as just like the expansion tank in your car. It should be no less than the low mark when fully cold. If it drops out of sight when cold, it is allowing air to be sucked into the cooling system, which the overflow tank is designed to prevent by keeping extra fluid available to be drawn in. My concern would be the fact that the level was at the low point 25 hours ago, and has now dropped out of sight. In a car with an overlflow tank, you would expect to operate for thousands of miles without any significant change in the level (when cold) unless something was wrong. Same thing in a boat, I believe. The 1st question is just how much you need to add to bring it back to the low point. Once you know that you will know the extent of the potential problem. Sometimes it may just need a pint or less, if the tank is small. If it needs much more than that, I would be watching the level carefully after filling it to the low mark (cold) to see just how fast it is dropping. I don't beieve that the change from summer to fall temperatures should be an issue, since the volume of water at 70 degrees or 40 degrees really doesn't change much. If you just need a small amount to bring the level to the mark, then it might just be temperature.
__________________
Mike sullivan
1985 Marshall 22 catboat
Reply With Quote Quick reply to this message Share with Facebook
  #9  
Old 11-14-2013
casioqv's Avatar
Senior Member
 
Join Date: Jun 2009
Location: Riverside, CA
Posts: 410
Thanks: 1
Thanked 2 Times in 2 Posts
Rep Power: 6
casioqv is on a distinguished road
Re: Engine coolant level

If you suspect a coolant leak, try pressure testing it with a bicycle pump to make sure it holds pressure. Also consider installing a float sensor with an audible alarm so you'll never let it run out of coolant.
Reply With Quote Quick reply to this message Share with Facebook
  #10  
Old 11-23-2013
Junior Member
 
Join Date: Sep 2011
Posts: 17
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
saillessinseattle is on a distinguished road
Ok, the coolant level is all the way to the top on the heat exchanger, and it is greenish yellow. The expansion tank is completely empty, and I know it wasn't back in the summer. Confirmed there are no visible leaks.

Sounds like we could pressure test it now (without draining it?). It is also safe to use for occasional limited distances. Would be ok to wait to drain/replace it by long life coolant in the spring, and pressure test it when it is empty?
Reply With Quote Quick reply to this message Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




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
draining the engine coolant - blocked! jaybeegee Gear & Maintenance 12 02-23-2013 06:12 PM
Connecting water heater to engine coolant edwmama Announcements and Suggestions Box 0 03-27-2011 01:41 AM
Rising Coolant Level..4108 avazquez Gear & Maintenance 0 05-20-2009 07:50 AM
Flushing engine coolant sailboy21 Gear & Maintenance 10 12-17-2008 02:14 PM
Where to put engine coolant expansion tank preservedkillick Gear & Maintenance 12 11-03-2008 05:17 AM


All times are GMT -4. The time now is 01:23 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

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.