3JH4e heat-exchanger cleaning

Last year I had a cooling water temp alarm, for the first time (1900 hours, 14 years) after running top rpm’s for some 10 minutes (trying to get there first :-) ) in hot weather.

So looking to clean the cooling system, specifically the heat exchanger  (and take a look at exhaust elbow while at it)

I was wondering what your thoughts are regarding  flushing (with something like barnacle buster, acid) vs taking the heat exchanger apart and mechanically cleaning the pipes etc.?

Any opinions and/or experience on this (with the 3JH4e)  ?

Thanks,

Peter

I did some precautionary maintenance a couple of years back including the exhaust elbow and heat exchanger.  While I can't recall what the manual says about elbow changes, I replaced mine at about 1350 hours and found it quite fouled.  Not sure from your post if yours has been changed already but if not then I'd have thought that 1900 hours would put it past its 'sell by' date.  I'm surprised at the report of difficulty getting the heat exchanger off; mine was quite straightforward and the results were well worth it.  While of course its more effort, doing this provides certainty which is much more comforting than the simple hope that whatever snake-oil you've put through the system will actually work. While I was at it, I replaced every single hose I could get at as well, again as a precautionary measure.

Oh the joys of owning a boat....

Iain

Do you have the 129670-13561 exhaust elbow or the 129470-13541 type? There are bought used on the 3jh4 and 4jh4 series engines I believe.

We have the Yanmar 4jh4 hte engine with the 129470-13541 and this elbow is a much better quality than the 129670-13561(old parts number 129670-13560) and normal for a longer lifespan. 

After 13 years and 3500 hours still like new and no problem.

They are not cheap you know