I was going to move my 31 today from Gandy Bridge to its new homeport on Treasure Island. I was about one hour out into the bay when Engine trouble hit. I was going about 5kts @ 2700 RPM. BTW, my Boat is in need of a bottom job and there is plenty of growth on the hull, but I cleaned the prop and shaft a little while ago. Sudddeny, I heard a sound like pffffffffffff and the enginge went down to idle and some black smoke came out the exhaust. I turned the engine of waited and started again. After 2 min. same thing. I decided to turn around, waited a little and went back at 1700 rpm making 2kts. No problems at that speed. 1-1/2 hour later nearly back at the harbour I tested it again it and ran 2500 rpm with no problem for about 5 minutes. I can't get the engine above 3000 PRM what I believe is because of the bottom. I checked the airfilter, where I found only a metal mesh but no filter, I found oil in the filter cover. I was under the impression that the exhaust looked a bit blueish, but not much at all. My problem is that my old marina closed (conco project) and kicked me out, I am in a hurry to vacate the boat and now this. Any information is welcome, might this be an easy fix, big job ? Thanks siggi
Help !!!! Yanmar 2GM 18hp
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First check
your fuel filters. The aircleaner on marine engines helps to keep the butterflies out of the engine but generally there isn't much of a dust problem. I think that from your discription I would check the linkages for the throttle and stop cables, check all of the fuel line from the tank to the primary filter to the engine and check the return line from the injectors to the tank. I think that the engine may be starving. You have more than enough HP to deal with a foul bottom. Edited to add: is it possible that you picked up a line and entangled the prop?
your fuel filters. The aircleaner on marine engines helps to keep the butterflies out of the engine but generally there isn't much of a dust problem. I think that from your discription I would check the linkages for the throttle and stop cables, check all of the fuel line from the tank to the primary filter to the engine and check the return line from the injectors to the tank. I think that the engine may be starving. You have more than enough HP to deal with a foul bottom. Edited to add: is it possible that you picked up a line and entangled the prop?
Maybe vale tolerance ?
The throttle and stop cable do work fine, there is nothing around the prop. Am not sure about the exhaust blockage. It was pretty signifiant the sound that hit, was very clear and long pffffffffffffffff and after it sounded to me (I am not a mechanic) like a vale that may not close well ... klick klick klick klick........ There was black smoke at the same time. Worked fine later at low RPM Fuel supply ?
The throttle and stop cable do work fine, there is nothing around the prop. Am not sure about the exhaust blockage. It was pretty signifiant the sound that hit, was very clear and long pffffffffffffffff and after it sounded to me (I am not a mechanic) like a vale that may not close well ... klick klick klick klick........ There was black smoke at the same time. Worked fine later at low RPM Fuel supply ?
Siggi, this isn't fair.
Too hard of a problem. Us guys who like these puzzles might be over challenged. That said, I'm still thinking,,,
OK, that pffffffff has me going. And the oil in the air cleaner. Any chance you overheated and the cap blew and the oil is really coolant?
Too hard of a problem. Us guys who like these puzzles might be over challenged. That said, I'm still thinking,,,
OK, that pffffffff has me going. And the oil in the air cleaner. Any chance you overheated and the cap blew and the oil is really coolant?
Yanmar Problem
You mentioned cleaning the prop "a little while ago" but how long has it been? If anything like my area along the northern Gulf Coast, it doesn't take long for a prop to foul quickly in Tampa waters. Your problem sounds similar to one that a friend experienced with his Yanmar: his was a badly fouled prop which had been cleaned one month earlier. The engine ran well when idling but would start acting up whenever put under a load. After checking everything, it turned out to be a fouled prop. Also, you may have picked up a line, plastic bag , or some other foreign object on the prop or shaft. It will only take a moment to check so dive in!
You mentioned cleaning the prop "a little while ago" but how long has it been? If anything like my area along the northern Gulf Coast, it doesn't take long for a prop to foul quickly in Tampa waters. Your problem sounds similar to one that a friend experienced with his Yanmar: his was a badly fouled prop which had been cleaned one month earlier. The engine ran well when idling but would start acting up whenever put under a load. After checking everything, it turned out to be a fouled prop. Also, you may have picked up a line, plastic bag , or some other foreign object on the prop or shaft. It will only take a moment to check so dive in!
siggib
I think Ross is on the right track. Was the pffffff accompanied by a deceleration at the same time? My thought is that the fuel filter has clogged. Know that clogs in the fuel filter act differently every time the engine starts. Remember that once the engine starts the fuel filter has pressure on it from the fuel. When the engine is shut down, the pressure is gone. When the engine has started up again, some of the particals may have moved allowing flow for a short period of time. Particals, slug, algae, water, ect. can foul a filter and cause similar but different problems. When and engine gets fuel properly, there are no problems. When the filter does not allow enough fuel though, the engine starves, for fuel and the engines acts sluggishly above an idle. This can pull oil up from the crank case because instead of a positive pressure it is a negative pressure in the cylinder. This could be the blue smoke you see. If it is running fine at low speeds, it is getting enough fuel though the lines to let you run at that speed, but as soon as you ask for a higher fuel demand the engine will feel like it is decelerating. r.w.landau
I think Ross is on the right track. Was the pffffff accompanied by a deceleration at the same time? My thought is that the fuel filter has clogged. Know that clogs in the fuel filter act differently every time the engine starts. Remember that once the engine starts the fuel filter has pressure on it from the fuel. When the engine is shut down, the pressure is gone. When the engine has started up again, some of the particals may have moved allowing flow for a short period of time. Particals, slug, algae, water, ect. can foul a filter and cause similar but different problems. When and engine gets fuel properly, there are no problems. When the filter does not allow enough fuel though, the engine starves, for fuel and the engines acts sluggishly above an idle. This can pull oil up from the crank case because instead of a positive pressure it is a negative pressure in the cylinder. This could be the blue smoke you see. If it is running fine at low speeds, it is getting enough fuel though the lines to let you run at that speed, but as soon as you ask for a higher fuel demand the engine will feel like it is decelerating. r.w.landau
Gas vs. Diesel
Sounds like contaminated fuel, possibly even gasoline ine your tank vs. diesel. Good luck, if it was gas, don't sweat it change the oil, polish the tank and carry on!
Sounds like contaminated fuel, possibly even gasoline ine your tank vs. diesel. Good luck, if it was gas, don't sweat it change the oil, polish the tank and carry on!
Foam Air Filter Element
Air Filters are metal mesh carying a foam filter material. Perhaps your foam filter was deteriorating and sucked into the engine. At some point the engine recovered after 'eating' the foam. Why not change the fuel filter(s) and check / change the oil and filter; install a new air filter. Then start the engine and check it's max RPM without the transmission in gear. A 2GM20 should run 3600 RPM under no load (don't do it for more than a minute or so just to check it out). If you can't get decent RPM after the fuel filter change it may be a clogged or at least partially restricted water injection elbow.
Air Filters are metal mesh carying a foam filter material. Perhaps your foam filter was deteriorating and sucked into the engine. At some point the engine recovered after 'eating' the foam. Why not change the fuel filter(s) and check / change the oil and filter; install a new air filter. Then start the engine and check it's max RPM without the transmission in gear. A 2GM20 should run 3600 RPM under no load (don't do it for more than a minute or so just to check it out). If you can't get decent RPM after the fuel filter change it may be a clogged or at least partially restricted water injection elbow.
Great response
Thanks for the fast response, I will check on those things. No overheating I am pretty sure. The pffffff was accompanied by deceleration at the same time. I cleaned the prop 6 weeks ago, but the dive service called me 2 weeks ago saying the bottom paint failed and prop looks ok. Rob you got me thinking for a minute and I checked my receite from the pump today, but it says Diesel on it. I added some Diesel Stabiliser this week, can't believe that would do any harm. I will go for the fuel filter and line first. Thanks siggi
Thanks for the fast response, I will check on those things. No overheating I am pretty sure. The pffffff was accompanied by deceleration at the same time. I cleaned the prop 6 weeks ago, but the dive service called me 2 weeks ago saying the bottom paint failed and prop looks ok. Rob you got me thinking for a minute and I checked my receite from the pump today, but it says Diesel on it. I added some Diesel Stabiliser this week, can't believe that would do any harm. I will go for the fuel filter and line first. Thanks siggi
Siggi,
You said you added Stabilizer to your fuel this week..... When you check the filter, see if there is a gelly like substance in the filter. I have seen this in Gasoline treated with Stabilizer. r.w.landau
You said you added Stabilizer to your fuel this week..... When you check the filter, see if there is a gelly like substance in the filter. I have seen this in Gasoline treated with Stabilizer. r.w.landau
Go for a swim
and dive on the propeller. If you picked up a piece of stray rope then the inspection two weeks ago won't help very much. Remove the bowl on those fuel filters and enpty them into something so you can see what you dumped. All of the things that you are being told are the things that a mechanic charging 75 dollars per hour is going to do. The most common cause of diesel engine problems is bad fuel. Rule that out before you resort to hiring a person that does the work that you can and should do before you call him.
and dive on the propeller. If you picked up a piece of stray rope then the inspection two weeks ago won't help very much. Remove the bowl on those fuel filters and enpty them into something so you can see what you dumped. All of the things that you are being told are the things that a mechanic charging 75 dollars per hour is going to do. The most common cause of diesel engine problems is bad fuel. Rule that out before you resort to hiring a person that does the work that you can and should do before you call him.
I would start with the exhaust elbow -
clean it out and then check fuel filters if that does not fix it. If it is not filters, try using a completely different fuel tank for a test. It could also be a bad lift pump or loose fittings or hoses leaking air. One time, I had a problem with the pickup tube having a screen on the low end. The screen had been collapsed so tightly that it would leak a little fuel over time but would not feed enough to allow the engine to run. It would start but then it would die. I have also heard of exhaust hose coming apart inside and a flap of it (inside the hose) blocking the exhaust but I haven't seen that myself.
clean it out and then check fuel filters if that does not fix it. If it is not filters, try using a completely different fuel tank for a test. It could also be a bad lift pump or loose fittings or hoses leaking air. One time, I had a problem with the pickup tube having a screen on the low end. The screen had been collapsed so tightly that it would leak a little fuel over time but would not feed enough to allow the engine to run. It would start but then it would die. I have also heard of exhaust hose coming apart inside and a flap of it (inside the hose) blocking the exhaust but I haven't seen that myself.
Siggi, your engine may have ingested
the foam part of the air filter. You said "I checked the airfilter, where I found only a metal mesh but no filter". Diesel engines suck up a very large volume of air and the pressure is very high. The quickest way to kill a runaway diesel is to starve it from air. If you had not checked your air filter in a long time, it is quite possible that it deteriorated badly enough to get sucked in. At that very moment, you would have had a sucking noise (pfffff ?)and immediate deceleration. Your going back at lower RPM might have shredded that foam into tiny pieces and exhausted it. With the the engine still running, even at lower RPM, that foam was being digested through the entire system, until exhausted. Then it should run again normally unless some piece got stuck somewhere creating an air flow resistance in the admission or a water flow restriction in the exhaust system. Hopefully, no piece got stuck anywhere. Follow the advice given previously: run your engine in neutral up to max RPM briefly, change the fuel filters (you could run without the air filter as there is almost no dust) and do check your prop again, then take her to your new place. Of course, as mentioned in another post, you could sail her there.
the foam part of the air filter. You said "I checked the airfilter, where I found only a metal mesh but no filter". Diesel engines suck up a very large volume of air and the pressure is very high. The quickest way to kill a runaway diesel is to starve it from air. If you had not checked your air filter in a long time, it is quite possible that it deteriorated badly enough to get sucked in. At that very moment, you would have had a sucking noise (pfffff ?)and immediate deceleration. Your going back at lower RPM might have shredded that foam into tiny pieces and exhausted it. With the the engine still running, even at lower RPM, that foam was being digested through the entire system, until exhausted. Then it should run again normally unless some piece got stuck somewhere creating an air flow resistance in the admission or a water flow restriction in the exhaust system. Hopefully, no piece got stuck anywhere. Follow the advice given previously: run your engine in neutral up to max RPM briefly, change the fuel filters (you could run without the air filter as there is almost no dust) and do check your prop again, then take her to your new place. Of course, as mentioned in another post, you could sail her there.
thanks
This was great help, I will go for the advice. If the wind is right I will sail most of it. Thanks again siggi
This was great help, I will go for the advice. If the wind is right I will sail most of it. Thanks again siggi
A couple more things
I had a similar problem this fall but the engine just died out. Had to sail it back to my mooring. I decided it had to be a fuel problem so I replaced both fuel filters and the fuel pump. The engine was 20 yrs old, and I figured the fuel pump was due anyway. I also installed a squeeze pump in the fuel line from the tank. This helped to bleed the air out of the lines and fill the filters. If the tank was obstructed, the squeeze pump would not fill back up. One of those things did the trick. One more thing, keep the raw water valve off when your cranking the engine so you don't flood the engine with seawater if she doesn't start. Turn it back on if she does start. Mine is a 3GM and the fuel pump is an inexpensive item.
I had a similar problem this fall but the engine just died out. Had to sail it back to my mooring. I decided it had to be a fuel problem so I replaced both fuel filters and the fuel pump. The engine was 20 yrs old, and I figured the fuel pump was due anyway. I also installed a squeeze pump in the fuel line from the tank. This helped to bleed the air out of the lines and fill the filters. If the tank was obstructed, the squeeze pump would not fill back up. One of those things did the trick. One more thing, keep the raw water valve off when your cranking the engine so you don't flood the engine with seawater if she doesn't start. Turn it back on if she does start. Mine is a 3GM and the fuel pump is an inexpensive item.
All the clues...
...point to an ingested foam element that caused the intake valve to stick open for a while, or a missing element and poor lube up to the valves, again causing the sticking. Hence the pfffff followed by klick klick klick and accompanied by smoke. You may have some blow-by as well??
...point to an ingested foam element that caused the intake valve to stick open for a while, or a missing element and poor lube up to the valves, again causing the sticking. Hence the pfffff followed by klick klick klick and accompanied by smoke. You may have some blow-by as well??
Note: Not all engines have foam filters.
Some are just meshed metal that acts as a spark arrestor. r.w.landau
Some are just meshed metal that acts as a spark arrestor. r.w.landau
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