SP2
Well-Known Member
The Yanmar 4LH-STE in my Channel Islands 22 has an issue. It has 185 recorded hours and was installed in 2005. It has been well maintained by previous owners and I have the service records. It was last professionally serviced in October but what with one thing and another, has had virtually no use since then.
On the first trip out this season in July there was an obvious problem which I diagnosed as a seized turbo. There was thick black exhaust smoke when the revs were increased above around 1400 and no increase in revs thereafter. The engine revs freely off load, and starts easily.
The engineers looked this week without me there, and said that they agreed that the turbo was probably seized or damaged as they could see dust on the air filter which would be due to a failure of the turbo. They also think that the head gasket has gone as they saw some white smoke in the exhaust and the coolant water was noted to raise and fall as the throttle was adjusted. I looked today and cannot see any dust but then I may not be looking for the right kind of "dust".
All my diesel engine experience has been with good old Fords and Perkins so this is new territory for me. I would have expected an issue if the oil or coolant was emulsified in some way and both of these appear fine.
The engineers' solution is to remove the turbo to investigate further, and to take off the head.
Looking to the experience of forumites, does this sound like the right approach to the problem? Is it a known issue with these engines? Is there some other tests that could be done regarding the head gasket before the engine is taken apart? Should I be concerned about removal of the head?
I aim to call the yard next week and ask to meet them to run through things on board before spanners are drawn and any assistance with what I should be looking for would be appreciated.
Thanks, Mike
On the first trip out this season in July there was an obvious problem which I diagnosed as a seized turbo. There was thick black exhaust smoke when the revs were increased above around 1400 and no increase in revs thereafter. The engine revs freely off load, and starts easily.
The engineers looked this week without me there, and said that they agreed that the turbo was probably seized or damaged as they could see dust on the air filter which would be due to a failure of the turbo. They also think that the head gasket has gone as they saw some white smoke in the exhaust and the coolant water was noted to raise and fall as the throttle was adjusted. I looked today and cannot see any dust but then I may not be looking for the right kind of "dust".
All my diesel engine experience has been with good old Fords and Perkins so this is new territory for me. I would have expected an issue if the oil or coolant was emulsified in some way and both of these appear fine.
The engineers' solution is to remove the turbo to investigate further, and to take off the head.
Looking to the experience of forumites, does this sound like the right approach to the problem? Is it a known issue with these engines? Is there some other tests that could be done regarding the head gasket before the engine is taken apart? Should I be concerned about removal of the head?
I aim to call the yard next week and ask to meet them to run through things on board before spanners are drawn and any assistance with what I should be looking for would be appreciated.
Thanks, Mike
