SailNet Community

SailNet Community (http://www.sailnet.com/forums/)
-   Diesel (http://www.sailnet.com/forums/diesel/)
-   -   Yanmar losing coolant (http://www.sailnet.com/forums/diesel/78709-yanmar-losing-coolant.html)

Tim R. 09-13-2011 02:17 PM

Yanmar losing coolant
 
Here is what I know:

Engine is a 14 year old Yanmar 4JH2E with 2000 hrs.

- Earlier in the season the engine would use a few ounces of coolant when I ran it about an hour or 2
- Now suddenly the coolant is disappearing at the rate of appr 64 ounces per hour
- No sign of coolant in the oil.
- No sign of oil in the coolant.
- No sign of coolant in the bilges or under the engine.
- Engine otherwise runs perfectly. Good power and smooth operation. Starts on first try.

Last night I performed some diagnostics with a pressure tester. Here are the results:
- Engine off, system pressurized to 16lbs, tester slowly lost pressure. Started the engine and AF came out the exhaust. Took a few tries to start.

- Refilled system, connected tester, started engine. No jump on the tester. If the gauge suddenly jumped up it could indicate a head gasket problem.

- Engine running, pressurized the system to 16lbs and needle did not jump around. If it did it could indicate cracked head or block. System slowly lost pressure.

I am thinking bad heat exchanger. I will pull it tonight to check.

dabnis 09-13-2011 05:07 PM

"System slowly lost pressure", Possibly coolant leaking into the raw water side of the heat exchanger? Or small leak in the head gasket?

Dabnis

JimsCAL 09-14-2011 12:08 AM

Heat exchanger would be my guess also.

svHyLyte 09-14-2011 11:03 AM

Quote:

Originally Posted by JimsCAL (Post 774354)
Heat exchanger would be my guess also.

Amen...

paperbird 07-01-2013 12:58 PM

Re: Yanmar losing coolant
 
whatever happened on your heat exchanger? I'm having some weird issues and suspect the HE so was searching the threads and found this one.

Capt Len 07-02-2013 10:54 PM

Re: Yanmar losing coolant
 
My vote is to replace heat exchanger .Make sure the sacrificial zincs in it are good and maintained.


All times are GMT -4. The time now is 08:21 PM.

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