Shibumi's Yanmar 3gm30f has about 1800 hours on it. Lately it's been getting harder to start when cold and is blowing white smoke out the exhaust on startup and leaving a small fuel or oil slick on the water near the exhaust. I had a consult on board on Friday with my diesel mechanic. He discovered high crankcase pressure which would cause oil to be forced out around the oil fill cap when loosened even a little bit with the engine running and significant pressure (estimated at 9 psi) out the crankcase breather. My mechanic believes this is caused by improperly seated or worn piston rings that are allowing exhaust gases to blow by into the crankcase. Nigel Calder's book would support that conclusion. At this point I can live with the reluctance to start and the engine is still running fine otherwise. My options appear to be three: 1. Live with it for now. This would be ok, but we sail some places that can get dicey on occasions and I don't want to feel compromised by a questionable engine. 2. Pull the engine and go through a spendy piston and piston ring, etc. replacement 3. Since I would be pulling the engine anyway and am committed to Shibumi for the long term, go ahead and replace the engine. I'm really not pleased this is happening so early in the engine's life. I've owned the boat for four years and have put maybe a third of the engine hours on it. It's had plenty of TLC. Not sure about it's early treatment, but up to now have had no problems with the engine. Any advice from the voices of experience will be appreciated. Gary Wyngarden S/V Shibumi H335
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Ed Schenck
Take it slow Gary.
That engine should be like new with 1800 hours. My first recommendation would be to review all the Q&A activity(Discussion Forums) on the Torresen site. You could even write them, Ike Torresen usually answers. See Related Link. Obviously the mechanic could be right but more tests are necessary I think.
That engine should be like new with 1800 hours. My first recommendation would be to review all the Q&A activity(Discussion Forums) on the Torresen site. You could even write them, Ike Torresen usually answers. See Related Link. Obviously the mechanic could be right but more tests are necessary I think.
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Bob
Stuck Ring(s)?
Gary, this will sound like a "snake oil' solution, but it is what I would try if it were my engine. I'd run some "Sea Foam" additive in the fuel and in the crankcase. This stuff is terrific for cutting through varnish, carbon, etc. Wish I had found out about it years ago. Many an otherwise good engine has been scrapped because the oil control rings were stuck. In fact, if you could introduce some full strength into the cylinders and let it sit several days, so much the better. I'd also strongly recommend Amsoil synthetic diesel oil in place of whatever you are now running in the crankcase. It penetrates better, handles bearing loads much better, and doesn't have anywhere near the build-up of conventional petroleum based products. It's expensive, but not compared to a rebuild.
Gary, this will sound like a "snake oil' solution, but it is what I would try if it were my engine. I'd run some "Sea Foam" additive in the fuel and in the crankcase. This stuff is terrific for cutting through varnish, carbon, etc. Wish I had found out about it years ago. Many an otherwise good engine has been scrapped because the oil control rings were stuck. In fact, if you could introduce some full strength into the cylinders and let it sit several days, so much the better. I'd also strongly recommend Amsoil synthetic diesel oil in place of whatever you are now running in the crankcase. It penetrates better, handles bearing loads much better, and doesn't have anywhere near the build-up of conventional petroleum based products. It's expensive, but not compared to a rebuild.
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Miles
Agree with go slow...
Hi Gary, Most engines are hard to start when it's cold out, since the Yanmar doesn't have any glow plugs it's even harder to get it going. While you're cranking the engine the injectors are squirting away and when the engine finally does start there is typically a lot of unburned diesel and smoke for a bit. How well does it start after it's warmed up and been shut off for a little while? Is this a new development or has it always been tough to start in the cold? Did the mechanic check the compression in the cylinders with a gauge? Does it run well once warmed up? How long since the last valve adjustment? I think you listed your options in the correct order. My guess is that a brand new $10,000 engine would probably also be hard to start in the cold. With only 1800 hours I'd be suprised if there was anything TOO wrong with it. Spring and Summer aren't too far away right? Maybe your engine will behave better when it's a bit warmer out. Good luck!
Hi Gary, Most engines are hard to start when it's cold out, since the Yanmar doesn't have any glow plugs it's even harder to get it going. While you're cranking the engine the injectors are squirting away and when the engine finally does start there is typically a lot of unburned diesel and smoke for a bit. How well does it start after it's warmed up and been shut off for a little while? Is this a new development or has it always been tough to start in the cold? Did the mechanic check the compression in the cylinders with a gauge? Does it run well once warmed up? How long since the last valve adjustment? I think you listed your options in the correct order. My guess is that a brand new $10,000 engine would probably also be hard to start in the cold. With only 1800 hours I'd be suprised if there was anything TOO wrong with it. Spring and Summer aren't too far away right? Maybe your engine will behave better when it's a bit warmer out. Good luck!
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Pete
engine blow by
Gary,don't be so quick to bury the engine, rings very seldom go bad overnight so unless this has been a on going problem I don't think you have any more then a hard starting cold diesel engine. This is just a fact of life with diesel engines. Have you every seen a big diesel truck start up in dead of winter?gray/white smoke all over! Some help might be to warm the engine with a cabin heater first( be careful) the real answer to if the rings are worn is to check the compression and if the engine has been using any oil.IMO I would live with for a while and keep a eye on things. 1800 hours is not a lot of hours for this engine and it should not need rings this soon (there is alway the exception to the rule)assuming it has had regular maintance.Even so a engine with blow by and bad rings can run for a long time! You have a concern about the engine being a question in "dicy" conditions but you did not mention lack of power or any other operating problems.I would opt for you option #1 Good Luck !
Gary,don't be so quick to bury the engine, rings very seldom go bad overnight so unless this has been a on going problem I don't think you have any more then a hard starting cold diesel engine. This is just a fact of life with diesel engines. Have you every seen a big diesel truck start up in dead of winter?gray/white smoke all over! Some help might be to warm the engine with a cabin heater first( be careful) the real answer to if the rings are worn is to check the compression and if the engine has been using any oil.IMO I would live with for a while and keep a eye on things. 1800 hours is not a lot of hours for this engine and it should not need rings this soon (there is alway the exception to the rule)assuming it has had regular maintance.Even so a engine with blow by and bad rings can run for a long time! You have a concern about the engine being a question in "dicy" conditions but you did not mention lack of power or any other operating problems.I would opt for you option #1 Good Luck !
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andy
go beat on it - Yanmars love to be run hard
Change the oil with fresh Penzoil 15-40 then go for a ride at full throttle /3600 rpm for an hour. Your diesel will love you for it. Most sail boat diesel problems are caused by short run times under light load. Beat that girl
Change the oil with fresh Penzoil 15-40 then go for a ride at full throttle /3600 rpm for an hour. Your diesel will love you for it. Most sail boat diesel problems are caused by short run times under light load. Beat that girl
Try everything else first.
Gary: I would have to agree with the previous posts. We know that Yanmar does not recommend additives but that is a good place to start. Oil and Fuel additives. Soy Diesel in a high concentration (50-100%) would also be something worth trying. Run the crap out of the engine 3200-3400 for several hours.
Gary: I would have to agree with the previous posts. We know that Yanmar does not recommend additives but that is a good place to start. Oil and Fuel additives. Soy Diesel in a high concentration (50-100%) would also be something worth trying. Run the crap out of the engine 3200-3400 for several hours.
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Dick McKee
My 2 cents..
Our 4jh2e began to smoke quite a bit on start up and then go away completely when it was warmed up. My solution was quite simple. Remove the injectors and clean the carbon build up on the tips and adjust the valves. The start up smoke was reduced by about 80%.
Our 4jh2e began to smoke quite a bit on start up and then go away completely when it was warmed up. My solution was quite simple. Remove the injectors and clean the carbon build up on the tips and adjust the valves. The start up smoke was reduced by about 80%.
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David
1800 Hours
Is not unusual for a sailboat diesel engine to develop problems. They take a lot more abuse than powerboats with comparable hours. In many cases they don't get a chance to warm up before they are shut down. I think I would back up the mechanics opinion by having another mechanic look at the engine.
Is not unusual for a sailboat diesel engine to develop problems. They take a lot more abuse than powerboats with comparable hours. In many cases they don't get a chance to warm up before they are shut down. I think I would back up the mechanics opinion by having another mechanic look at the engine.
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Andy
The blow by
The blow by that you are getting is from an anxious mechanic and some thick oil. Take you time and let it have some rollover time to start. As suggested earlier, even some carboned up injector tips could make it a little hard to start. BTW, have you checked your fuel? It could be a little weak (watered down or oiled up) and that could be making Yani a little hesitant to chug.
The blow by that you are getting is from an anxious mechanic and some thick oil. Take you time and let it have some rollover time to start. As suggested earlier, even some carboned up injector tips could make it a little hard to start. BTW, have you checked your fuel? It could be a little weak (watered down or oiled up) and that could be making Yani a little hesitant to chug.
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Al Miegel
A definative test for blow by is.....
Called a leak down test. I agree with most of the posts and suspect your rings are simply stuck. Leak down testers are the best test for cylinder leakage. Try Rislone "Ring Free" and run that puppy hard for a bit, then change the oil. 9 PSI is a bit high for crank pressure, but even on a new motor you have pressure build up in the crankcase. You've got nothing to loose by trying an additive first.
Called a leak down test. I agree with most of the posts and suspect your rings are simply stuck. Leak down testers are the best test for cylinder leakage. Try Rislone "Ring Free" and run that puppy hard for a bit, then change the oil. 9 PSI is a bit high for crank pressure, but even on a new motor you have pressure build up in the crankcase. You've got nothing to loose by trying an additive first.
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Gary Wyngarden
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