jwilson
Well-Known Member
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 the overheating 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.
Yanmar 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 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 necessary.
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!
Not impressive customer service from Yanmar ..... A pity as I generally like their engines.
Yanmar 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 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 necessary.
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!
Not impressive customer service from Yanmar ..... A pity as I generally like their engines.
