Cruisers Forum

Join CruisersForum Today

Thread Tools Rate Thread Display Modes
Old 09-05-2009, 03:21   #1
Registered User

Join Date: Mar 2008
Location: On our yacht Byamee
Boat: Footloose 40 steel cutter
Posts: 316
Images: 1
Heat Exchanger Coolant Overflow

I'm having a very slight overheating problem which is also effecting the heat exchanger on my engine driven eutectic fridge which gets its cooling water from the motor heat exchanger. The motor is a Brittish Leyland fisherboy an oldie but a reliable goodie .The heat exchanger on the leyland has an overflow pipe which empties into the bilge,I have had to top up the heat exchanger with coolant every trip ,obviously this is not right so i checked for leaks which i found and fixed but the problem still remains,so i got the end of the overflow pipe and stuck it in a bottle and over 2 hours of motoring about 500 to 600 mils half a litre came out of the heat exchanger.
Could any of you Diesel experts tell me if this is normal or do i have a heat exchanger problem .Motor is only running a little hot not enough to set off alarm.
Attached Thumbnails
Click image for larger version

Name:	motor...jpg
Views:	163
Size:	523.4 KB
ID:	8065  

TOM is offline   Reply With Quote
Old 09-05-2009, 08:46   #2
Registered User

Join Date: Oct 2007
Location: virginia
Boat: islandpacket
Posts: 1,881
Check or replace the pressure cap on the cooling system. Cars and my boat have a collection container that holds the expanding heated water and as the system cools the water is sucked back into the engine. Maybe a good flush of the system. Has there been a change of antifreeze?

That derelict boat was another dream for somebody else, don't let it be your nightmare and a waste of your life.
Badsanta is offline   Reply With Quote
Old 09-05-2009, 10:37   #3
Registered User

Join Date: Mar 2008
Boat: Little Harbor Whisperjet 40
Posts: 334
This could be a sign of a failed heat exchanger. This happened to me last year. The overflow tank (you should have one) kept filling up and running into the bilge. The salt water side has greater pressure when the engine is running fast, than the fresh side does. Constantly pushing salt water in and dispacing coolant which runs to the bilge.
Eventually the engine coolant will be all salt water.
A quick test is to check the specific gravity with a common auto antifreeze tester.
The more invasive test it to remove the heat exchanger, boil it out and pressure test.
Highlander40 is offline   Reply With Quote
Old 09-05-2009, 15:04   #4
Registered User

Join Date: Aug 2008
Location: San Diego, CA
Boat: Jeanneau Sunkiss 47
Posts: 39
When you say top up..... You do leave at least a pint of room for expansion, correct?? If you top it to the top, it will blow a pint or so out as it gets hot and expands.

Or.. you could have a leak in the heat exchanger and the coolant is going out the exhaust. We (who do it for a living) carry a pressure checker with us and would put it in place of radiator cap and see if you are loosing pressure. If not, no leak.

If the coolant is not under the engine, not under the hot water heater, not in the bilge, not mixed with engine oil, its going out the exhaust. Bad heat exchanger. Or... some of them have a gasket between the coolant and salt and maybe leaking there.

HorizonMarine is offline   Reply With Quote
Old 10-05-2009, 01:44   #5
Registered User

Join Date: Mar 2008
Location: On our yacht Byamee
Boat: Footloose 40 steel cutter
Posts: 316
Images: 1
Thanks for all your replies .HorizonMarine I have been filling it right to the top so this could be the problem as about a pint is coming out .I will leave it as it is and see what happens . Highlander40 thanks for your responce I'm hopeing you are wrrong as the heat exchanger was replaced in 2004.
TOM is offline   Reply With Quote
Old 10-05-2009, 06:00   #6
Writing Full-Time Since 2014
thinwater's Avatar

Join Date: Nov 2008
Location: Deale, MD
Boat: PDQ Altair, 32/34
Posts: 4,809
It is also not expensive to have coolant tested for chloride.

Amalgatech or Southwest Research or others.

Gear Testing--Engineering--Sailing
Writing full-time since 2014
thinwater is online now   Reply With Quote

coolant, heat exchanger

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
Heat Exchanger Problem TOM Engines and Propulsion Systems 8 11-05-2017 03:05
Yanmar Heat Exchanger rvennis Engines and Propulsion Systems 8 12-06-2014 18:30
Heat exchanger Chrisc Engines and Propulsion Systems 3 17-12-2008 21:57
Rebuilding heat exchanger andrejsv Engines and Propulsion Systems 5 13-10-2008 14:19
Need heat exchanger for 4-108 mobetah Classifieds Archive 0 23-09-2008 19:35

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 18:41.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.