Cruisers Forum
 


Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 24-06-2021, 00:19   #1
Registered User

Join Date: Jan 2011
Posts: 45
Losing coolant

Twice now, I have gotten to my boat to notice that the coolant in the reservoir is severely depleted. This has happened twice over the last 2 months. I have topped it off and checked the levels between instances, but have not seen any drop in fluid.....


What could be causing this?


I have not seen any coolant in the bilge, or any obvious leaking. I did change the heat exchanger zinc the other day, but that should be on the salt water side of the system. There has not seemed to be any drops after the last couple of times I went out in the boat.


I have heard some rattling in the front of the engine, which could be the water pump, but not sure about that....again, no obvious signs of leaks.



I am going to do an oil change and see if the oil looks normal or has anything obvious in it.


My very uneducated guesses as to where it could be going is
a) overboard due to maybe a leak in the heat exchanger
b) into the oil pan due to an internal leak
c) into the bilge and I am just not seeing it
d) into the hot water tank due to a leak in its heat exchanger


Any other potential places, and how do I test the above?

Or am I missing something obvious (always a possibility)?
DenisHeinrichs is offline   Reply With Quote
Old 24-06-2021, 00:54   #2
Registered User

Join Date: Mar 2018
Location: New Zealand
Boat: 50í Bavaria
Posts: 1,843
Re: Losing coolant

I think you have the most obvious ones listed. If your engine bay is clean and your coolant green (or otherwise identifiable) you can discount hose leaks into the bilge. If your hot water isn't disgusting it's not going there.

That leaves the coolant temperature as your clue. Over temperature coolant (and milky oil in the engine) would suggest to me the leak is in the "engine" part of the engine. No unusual temperatures and clean oil suggest it's leaking into the salt water side of the heat exchanger.
Tillsbury is offline   Reply With Quote
Old 24-06-2021, 08:14   #3
Senior Cruiser
 
tkeithlu's Avatar

Cruisers Forum Supporter

Join Date: Feb 2012
Location: Carrabelle, Florida
Boat: Fiberglas shattering 44' steel trawler
Posts: 3,499
Re: Losing coolant

Thoroughly agreeing with Tillsbury, let me add:

A quick check of your dipstick will tell you if coolant is going into the engine oil. Coolant is 50% or better water, so you'd have a milkshake in your pan.

Overheating and over pressurizing the coolant should show in discharge out the side of the coolant cap - that makes quite a mess, so it doesn't sound likely.

I'm betting you've got a leak in the heat exchanger. It may only be showing up when the engine is hot and the cooling system pressurized.
__________________
Never let anything mechanical know that you are in a hurry.
tkeithlu is offline   Reply With Quote
Old 24-06-2021, 08:18   #4
Registered User

Join Date: Aug 2010
Posts: 2,124
Re: Losing coolant

If you're loosing coolant and it isn't in the bilge, the most common location is pin holes in the heat exchanger. The closed cooling side is much higher pressure than the raw water side. When (not if) holes develop, the higher pressure of the closed cooling side causes the coolant to leak into the raw water side and get discharged out the exhaust. It's usually a very slow process.
Shrew is offline   Reply With Quote
Old 24-06-2021, 08:19   #5
Registered User

Join Date: Jan 2011
Posts: 45
Re: Losing coolant

Quote:
Originally Posted by tkeithlu View Post
Thoroughly agreeing with Tillsbury, let me add:

A quick check of your dipstick will tell you if coolant is going into the engine oil. Coolant is 50% or better water, so you'd have a milkshake in your pan.

Overheating and over pressurizing the coolant should show in discharge out the side of the coolant cap - that makes quite a mess, so it doesn't sound likely.

I'm betting you've got a leak in the heat exchanger. It may only be showing up when the engine is hot and the cooling system pressurized.

I agree that the heat exchanger sounds like the culprit. The thing that confuses me is that it has only shown up when the engine is cold and has been sitting for days (it has only happened twice). After running the engine for hours and checking over the next couple of weeks....no loss in coolant.
DenisHeinrichs is offline   Reply With Quote
Old 29-06-2021, 09:59   #6
Registered User

Join Date: Jan 2011
Posts: 45
Re: Losing coolant

Here is an update:


I had the heat exchanger serviced. It was apparently really plugged but after the chemical bath to clean it....no leaks. It is actually in really good condition.....


Still stumped.....


I am going to go do a full oil change and see if there is anything noticable in the oil......
DenisHeinrichs is offline   Reply With Quote
Old 29-06-2021, 10:08   #7
Registered User
 
deblen's Avatar

Join Date: Oct 2014
Location: Grand Manan,N.B.,Canada N44.40 W66.50
Boat: Mascot 28 pilothouse motorsailer 28ft
Posts: 2,219
Images: 1
Re: Losing coolant

Suggest you purchase :


https://www.amazon.com/radiator-pres...ure+tester+kit
__________________
My personal experience & humble opinions-feel free to ignore both
.
deblen is offline   Reply With Quote
Old 29-06-2021, 10:38   #8
Registered User

Join Date: Aug 2010
Posts: 2,124
Re: Losing coolant

Quote:
Originally Posted by DenisHeinrichs View Post
Here is an update:


I had the heat exchanger serviced. It was apparently really plugged but after the chemical bath to clean it....no leaks. It is actually in really good condition.....


Still stumped.....


I am going to go do a full oil change and see if there is anything noticable in the oil......
Check your oil and see if you 'grew' any oil over time.
Shrew is offline   Reply With Quote
Old 29-06-2021, 23:17   #9
Registered User

Join Date: Feb 2010
Location: Australia
Posts: 818
Re: Losing coolant

How much coolant loss are we talking about here, 250ml? 2 litres.
Is it a small expansion tank or a big ol Volvo one??
skipperpete is online now   Reply With Quote
Old 30-06-2021, 00:53   #10
Registered User

Join Date: Jan 2011
Posts: 45
Re: Losing coolant

I figure I lost about 2 litres on each occurance. The engine is a Ford Lehman 80.


I have put the newly service heat exchanger back on, and have also replaced the fresh water pump (shouldn't it be called coolant pump?) with the brand new spare that I have.

Tomorrow I will top up the coolant and hope for the best.

Ideally, I guess I should get a pressure tester and see if all is good, but I leave on the boat on Thursday for a couple of months up the BC coast.
DenisHeinrichs is offline   Reply With Quote
Old 30-06-2021, 02:17   #11
Certifiable Refitter/Senior Wannbe
 
Wotname's Avatar

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: C.L.O.D.
Posts: 12,762
Re: Losing coolant

Quote:
Originally Posted by DenisHeinrichs View Post
I figure I lost about 2 litres on each occurance. The engine is a Ford Lehman 80.

.........
Some (many?) Lehmans have three heat exchangers - one for the coolant, one for the engine oil and one for the gearbox fluid.

Presumably you have checked all of them.

Can the coolant escape from the coolant cooled exhaust manifold and go down the exhaust?
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is online now   Reply With Quote
Old 30-06-2021, 08:10   #12
Registered User

Join Date: Jan 2011
Posts: 45
Re: Losing coolant

Quote:
Originally Posted by Wotname View Post
Some (many?) Lehmans have three heat exchangers - one for the coolant, one for the engine oil and one for the gearbox fluid.

Presumably you have checked all of them.

Can the coolant escape from the coolant cooled exhaust manifold and go down the exhaust?

Only the main heat exchanger has coolant in it. The other two just use sea water.
DenisHeinrichs is offline   Reply With Quote
Old 30-06-2021, 15:15   #13
Registered User

Join Date: Feb 2010
Location: Australia
Posts: 818
Re: Losing coolant

AHA! Ford Lehman. That totally changes the game. The exhaust manifold is coolant cooled, and has a bleeder/vent on the front end plate and the mixer elbow on the other end.... both ends are sealed by gaskets to contain the coolant.
Pete.
skipperpete is online now   Reply With Quote
Old 30-06-2021, 15:28   #14
Certifiable Refitter/Senior Wannbe
 
Wotname's Avatar

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: C.L.O.D.
Posts: 12,762
Re: Losing coolant

Quote:
Originally Posted by DenisHeinrichs View Post
Only the main heat exchanger has coolant in it. The other two just use sea water.
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is online now   Reply With Quote
Reply

Tags
coolant

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
Perkins 4-108 losing coolant dneve Engines and Propulsion Systems 23 13-12-2017 10:10
losing coolant from Yanmar 4JH-H2E sailingduke50 Engines and Propulsion Systems 6 24-09-2013 12:06
Yanmar 3GM30F losing coolant Deepdraft Engines and Propulsion Systems 14 16-08-2012 20:55
Losing Coolant - Need Some Advice keao Engines and Propulsion Systems 14 06-12-2011 20:39
Losing Coolant from Heat Exchanger sneuman Construction, Maintenance & Refit 1 26-06-2009 13:06

Advertise Here


All times are GMT -7. The time now is 16:59.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.