I have just seen the following post on a different forum and would like to bring it to your attention. The post refers to what has happened in UK, obviously I have no knowledge of other countries:
"Approximately the first 5,500 Yanmar 3YM30
diesels supplied to boatbuilders and fitted in Jeanneaus and US-type Hunters (amongst others) have an overheating
problem, usually showing up only after about 100/150 hours running, and when the sea water
temperature rises in summer. On my engine
warning light/beeper was going off, and a check by an engineer
with a temperature guage showed the engine
was genuinely overheating, not just having an over-sensitive warning light sensor.
and their distributors in the UK, EP Barrus, know of this problem, and are fixing it under warranty. However they are NOT warning users in advance of this known problem. They also appear not to be even telling their service
dealers about this - the first my local dealer knew was when I told him - I found the first references
to this on the web relating to US-marketed Jeanneaus.
Fortunately I found the problem on my engine (in a 2005 model Sun Odyssey 35 with 90 hours) before departing on a longish cruise
, and it was fixed just before departure. I met up two days ago with another owner of a similar boat
who had to delay his cruise
west mid-holiday while the Weymouth Yanmar dealer got the parts
and did the fix on his engine (at 125 hours).
These early (2004/2005) engines have a 38-tube heat exchanger
, and some very early engines were reportedly also fitted with a smaller capacity water
pump">raw water pump than is now used. The fix is to replace the original 38-tube heat exchanger core
with a new 63-tube one, and change the water pump
If you have a Yanmar 3YM30
with an engine serial
number under 6,000, I suggest you phone
EP Barrus and ask if your engine is affected. I am not sure of the exact number of the last of the faulty batch, but Barrus know. Don't rely on your Yanmar dealer having just serviced the engine to know about this!"