I have a few questions!! I was motoring yesterday and out of nowhere the engine stalled. I have been motoring for about a total of 3 hours that day but not straight though. This happened only after the egine had been running for about 15 mins once I left my anchorage. it started back up about 45secs later but the temp was up around 240 degrees. My engine usually runs at about 180. Any ideas about either topic, the stallin or the rise in temp? Are the related at all? I have a universal m-25 with about 400 hours on it.
Diesel Stalled
- Thread starter jaydog5000
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You've got a number of things
to check: I initially thought your problem was going to be air leaking into your fuel system which will cause an engine to stall. But the high temp you reported suggests the real problem is your cooling system. I'd begin by checking the coolant level is correct. Then check your raw water impeller to make sure it, and the pump housing it works in, is in good condition. Pay particular attention to the cam in the housing as well as the pump cover itself to make sure it is making a waterproof seal. Finally, make sure your raw water intake hoses/seacock/ and filter are not clogged. Finally, I'd check for the correct opening/closing of your thermostat as it may be time to replace it. Lots of stuff in the archives or online for how to do that. Good luck with this.
to check: I initially thought your problem was going to be air leaking into your fuel system which will cause an engine to stall. But the high temp you reported suggests the real problem is your cooling system. I'd begin by checking the coolant level is correct. Then check your raw water impeller to make sure it, and the pump housing it works in, is in good condition. Pay particular attention to the cam in the housing as well as the pump cover itself to make sure it is making a waterproof seal. Finally, make sure your raw water intake hoses/seacock/ and filter are not clogged. Finally, I'd check for the correct opening/closing of your thermostat as it may be time to replace it. Lots of stuff in the archives or online for how to do that. Good luck with this.
Be careful
There are too many variables to make an accurate diagnosis If you run at 180 and you are running under load for a while and the engine stops without the benifit of some cool down time at idle it is not unusual to see a rise in temperature as the hot motor soaks the water in the system around it. With a 12 pound or higher pressure cap and anti freeze in the system I would not worry about 240 . Under pressure and with antifreeze it probably not reached boiling point The question as to wether you have a cooling problem would have been answered after you restarted ... Did the temp come down fairly quickly indicating you just had a heat soak or did it stay or go higher ...then you may have a cooling problem
There are too many variables to make an accurate diagnosis If you run at 180 and you are running under load for a while and the engine stops without the benifit of some cool down time at idle it is not unusual to see a rise in temperature as the hot motor soaks the water in the system around it. With a 12 pound or higher pressure cap and anti freeze in the system I would not worry about 240 . Under pressure and with antifreeze it probably not reached boiling point The question as to wether you have a cooling problem would have been answered after you restarted ... Did the temp come down fairly quickly indicating you just had a heat soak or did it stay or go higher ...then you may have a cooling problem
temp rose
The Tempature rose about 20 degrees to 240. The raw water pump and impellar are both brand new this season. Would the over heating casue the stalling?
The Tempature rose about 20 degrees to 240. The raw water pump and impellar are both brand new this season. Would the over heating casue the stalling?
Sequence is importatn
When did you look at the temp gage? If the engine died and then a minuted or two later you looked at the gage the temp may well have climbed to 240 F. This is common but not often observed. All engines cooling systems heat up after shutdown and the cooling water stops flowing. The dynamic heat loss that was occurring with both pumps running has stopped but the residual heat still needs to get out through the cooling jacket. The only way that is going to happen is a temp spike in the fresh water cooling system. So, you may have only seen what most folks never see because the gages are turned off. With that said, the engine stopped for some reason. Was it a sudden "thunk" or an "RPM drops off smoothly over the course of a few seconds" or a "knock, shake, knock, bang, bang, bang" kind of stop. Did any sound or vibrations precede the stop? For the record, idling the engine for 2-3 minutes before shutting it down will minimize the temp spike. this is true for your car after coming off the interstate for a pee brake too.
When did you look at the temp gage? If the engine died and then a minuted or two later you looked at the gage the temp may well have climbed to 240 F. This is common but not often observed. All engines cooling systems heat up after shutdown and the cooling water stops flowing. The dynamic heat loss that was occurring with both pumps running has stopped but the residual heat still needs to get out through the cooling jacket. The only way that is going to happen is a temp spike in the fresh water cooling system. So, you may have only seen what most folks never see because the gages are turned off. With that said, the engine stopped for some reason. Was it a sudden "thunk" or an "RPM drops off smoothly over the course of a few seconds" or a "knock, shake, knock, bang, bang, bang" kind of stop. Did any sound or vibrations precede the stop? For the record, idling the engine for 2-3 minutes before shutting it down will minimize the temp spike. this is true for your car after coming off the interstate for a pee brake too.
Slow stall
The engine was a slow stalling with a drop in RPMs and then died. And yes I didn't look at the gauge until after the stalling.
The engine was a slow stalling with a drop in RPMs and then died. And yes I didn't look at the gauge until after the stalling.
Great and Oaw Crap
OK, a slow grind down to stall is a sign of excess drag. That can come from the following: Engine operating at too high a temp and the pistons expand and don't fit the cylinders any more. They expand slowly (after some cooling/oiling failure event) and the excess drag increases as the temp rises. Oil pressure dropped off and the bearing got scratched. The scratches got bigger and bigger or more and more till they drug the engine down. Since the engine started right back up and you did not report any decrease in performance, or "bad" noises I'd be guessing that it was the former and not the latter. I've seen engines with "scored rings/piston skirts" that ran for many thousands of miles and didn't even have an oil consumption problem. You should keep an eye on the oil level to confirm you are not using more than usual. I've never seen this happen due to a cooling problem. If the engine is that hot you would have some indication of an overheat in addition to the high cooling water temp. ie steam coming out the pressure cap FIRST. Where I have seen it is an oil supply failure. In the case I observed the guy (looked like me and sounded like me but I was never there) ran the motorcycle engine so fast that all the oil got "stuck in the head" and there was none for the oil pump to supply to the pistons. The bearings can take a lot more oil starvation than the piston rings because they have an oil film that protects them and that has to wear off. The piston rings and skirts need a constant supply of oil to cool them and so go first. Where you running the engine at WOT and is the crankcase oil level correct? The motorcycle guy drove it for many thousands of miles and when he re-bored the engine I just happen to be there as he was taking the head off. There was a weld down the cylinder the length of the piston stroke and a big cavity in the skirt opposite it. The bike ran fine though.
OK, a slow grind down to stall is a sign of excess drag. That can come from the following: Engine operating at too high a temp and the pistons expand and don't fit the cylinders any more. They expand slowly (after some cooling/oiling failure event) and the excess drag increases as the temp rises. Oil pressure dropped off and the bearing got scratched. The scratches got bigger and bigger or more and more till they drug the engine down. Since the engine started right back up and you did not report any decrease in performance, or "bad" noises I'd be guessing that it was the former and not the latter. I've seen engines with "scored rings/piston skirts" that ran for many thousands of miles and didn't even have an oil consumption problem. You should keep an eye on the oil level to confirm you are not using more than usual. I've never seen this happen due to a cooling problem. If the engine is that hot you would have some indication of an overheat in addition to the high cooling water temp. ie steam coming out the pressure cap FIRST. Where I have seen it is an oil supply failure. In the case I observed the guy (looked like me and sounded like me but I was never there) ran the motorcycle engine so fast that all the oil got "stuck in the head" and there was none for the oil pump to supply to the pistons. The bearings can take a lot more oil starvation than the piston rings because they have an oil film that protects them and that has to wear off. The piston rings and skirts need a constant supply of oil to cool them and so go first. Where you running the engine at WOT and is the crankcase oil level correct? The motorcycle guy drove it for many thousands of miles and when he re-bored the engine I just happen to be there as he was taking the head off. There was a weld down the cylinder the length of the piston stroke and a big cavity in the skirt opposite it. The bike ran fine though.
also consider the rw pump faceplate
Since you reported changing your impeller, did you check the faceplate? Oberdorfer or Sherwood pump?
Since you reported changing your impeller, did you check the faceplate? Oberdorfer or Sherwood pump?
Fuel Filter
Check the fuel system also. I have seen where the diesel gets contaminated and then the filters clog up and you can't get enough fuel pressure or flow to run at higher power settings, it might idle fine but stalls under load. Drain some fuel off the filter into a ziploc bag and look at it, any sign of debris or a gooey mess and you may have to drain the tank , clean, and refill.
Check the fuel system also. I have seen where the diesel gets contaminated and then the filters clog up and you can't get enough fuel pressure or flow to run at higher power settings, it might idle fine but stalls under load. Drain some fuel off the filter into a ziploc bag and look at it, any sign of debris or a gooey mess and you may have to drain the tank , clean, and refill.
Keep it simple
Check the water strainer, check the impellor, check the fuel filters. If you haven't had your fuel tank cleaned - consider adding an access plate so you can do that job too. Fuel is everything with diesels - probably 80 percent of all problems.
Check the water strainer, check the impellor, check the fuel filters. If you haven't had your fuel tank cleaned - consider adding an access plate so you can do that job too. Fuel is everything with diesels - probably 80 percent of all problems.
Inspection Plate
I didn't have this issue, but I installed the inspection plate and cleaned the fuel tank. I used the Seabuilt plate. A little pricey but seems like the best solution. I did notice before that every time I changed the fuel filter, it was quite dirty with small particles. since the boat having other work done, I siezed the opportunity and added the plate. I was amazed how much gunk was in a 4 year old tank. I'd estimate a 1/4 inch of blank gunk. This is my first season with the boat but now I have better piece of mind that my tank is clean. Like GuyT suggested, the top three problems with a diesel are caused by bad fuel, bad fuel and bad fuel.
I didn't have this issue, but I installed the inspection plate and cleaned the fuel tank. I used the Seabuilt plate. A little pricey but seems like the best solution. I did notice before that every time I changed the fuel filter, it was quite dirty with small particles. since the boat having other work done, I siezed the opportunity and added the plate. I was amazed how much gunk was in a 4 year old tank. I'd estimate a 1/4 inch of blank gunk. This is my first season with the boat but now I have better piece of mind that my tank is clean. Like GuyT suggested, the top three problems with a diesel are caused by bad fuel, bad fuel and bad fuel.
Similar Problem
Jaydog, I've been having a similar problem with my Univ 25XP. When it's been running for a while (a couple of hours), when I back the throttle off to put it in idle, the engine stalls. My problem is then having difficulty restarting. After the stall, the temp does climb to 220-240F (after running 160-180F), but I attribute the rise to the fact that cooling water stopped and I have observed that the temp does not rise until AFTER the stall. The first time it stalled I changed all the fuel filters, bled the system and she still wouldn't start. The impellers are brand new and the pump was fine. When I tried to turn her over, it was like something was loading the engine down; the starter could barely turn the crankshaft. The stalls always happen at an inopertune time - like when trying to anchor or turn down the row in the marina to my slip. I had a diesel mechanic look at it a week after the first stall. Unfortunately, we couldn't duplicate the stall, but we didn’t run it that long. He did clean a little algae out of the fuel pipe in the tank. Of course the next time out she stalled again, after running for over two hours at 80%, BUT, here's what worked. 1. To restart, I held the decompression lever, cranked the starter to get it really winding up, and then let the decompression lever go. It turned right over. 2. THEN, once I got her restarted, I let her idle for about fifteen minutes until the temp came down to 160F ish. I switched it off and it restarted just fine (no “loading”). Since then I always slowly ease the throttle back for several minutes, allowing the engine to cool to 160 before going into neutral. It has not stalled since, but does anyone know what is causing this?
Jaydog, I've been having a similar problem with my Univ 25XP. When it's been running for a while (a couple of hours), when I back the throttle off to put it in idle, the engine stalls. My problem is then having difficulty restarting. After the stall, the temp does climb to 220-240F (after running 160-180F), but I attribute the rise to the fact that cooling water stopped and I have observed that the temp does not rise until AFTER the stall. The first time it stalled I changed all the fuel filters, bled the system and she still wouldn't start. The impellers are brand new and the pump was fine. When I tried to turn her over, it was like something was loading the engine down; the starter could barely turn the crankshaft. The stalls always happen at an inopertune time - like when trying to anchor or turn down the row in the marina to my slip. I had a diesel mechanic look at it a week after the first stall. Unfortunately, we couldn't duplicate the stall, but we didn’t run it that long. He did clean a little algae out of the fuel pipe in the tank. Of course the next time out she stalled again, after running for over two hours at 80%, BUT, here's what worked. 1. To restart, I held the decompression lever, cranked the starter to get it really winding up, and then let the decompression lever go. It turned right over. 2. THEN, once I got her restarted, I let her idle for about fifteen minutes until the temp came down to 160F ish. I switched it off and it restarted just fine (no “loading”). Since then I always slowly ease the throttle back for several minutes, allowing the engine to cool to 160 before going into neutral. It has not stalled since, but does anyone know what is causing this?
M25 Diagnostics
1. Stalls when brought to idle: check the linkage at the engine end of the throttle lever. Also check inside the binnacle. Don't simply assume that when bring the throttle back everything is fine. Until you do so, then just don't bring the engine down to less than 1100 or so rpms. 2. Slow starting: check the wiring to the starter. Especially the connections. See: http://c34.org/bbs/index.php?topic=3823.0 3. Hot after shutdown: the engine manual says to cool down the engine after long running. It's in the manual, it's in the manual, it's in the manual. Read what???
1. Stalls when brought to idle: check the linkage at the engine end of the throttle lever. Also check inside the binnacle. Don't simply assume that when bring the throttle back everything is fine. Until you do so, then just don't bring the engine down to less than 1100 or so rpms. 2. Slow starting: check the wiring to the starter. Especially the connections. See: http://c34.org/bbs/index.php?topic=3823.0 3. Hot after shutdown: the engine manual says to cool down the engine after long running. It's in the manual, it's in the manual, it's in the manual. Read what???
jecraiq86
Sounds like you have an oil starvation problem. Of course check the oil level. also check the viscosity. Rub that nice black oil through your fingers and see if it is as "friction reducing" as new oil. It could be that your oil is contaminated or needs changing. I commented on another post about how much dirty oil the dip stick method can leave in your engine. Or you might have a fuel leak that is diluting the oil. From what you describe the engine stalls when you have her at operating temp and at low RPMs. This could be oil that has thinned out and while you can get the necessary lub at higher RPMs due to the increased pressure in the oil system, once you slow down with hot oil, the "thinning" effect causes you to loose lubrication and the extra drag/friction stalls the now slow running engine. Your restart problem sounds like either the starter/battery is too hot to provide the necessary current (doubtful) or the engine has seized a bearing. Once she cools down she might just tear through the seize and operate normally till the next time she is hot and slowed down. Start listening for "bang, bang, bang" noises. They will start as "knock, knock, knock" and get rapidly (20-30 minutes) louder. They will vary with engine speed as it is the piston rod pounding against the crank bearing. The crank bearings are sacrificial and PROMPT a) stopping of the engine when the sounds occur and b) replacement of the crank bearings will save you from buying new piston rods or crankshaft. I'd say you might also want to check the cooling heat exchanger for scaling but that is a secondary issue. I've never seen an engine stop due to cooling without having steam come out of the cap first. You might want to practice up on close quarters sail handling!!!! ;-)
Sounds like you have an oil starvation problem. Of course check the oil level. also check the viscosity. Rub that nice black oil through your fingers and see if it is as "friction reducing" as new oil. It could be that your oil is contaminated or needs changing. I commented on another post about how much dirty oil the dip stick method can leave in your engine. Or you might have a fuel leak that is diluting the oil. From what you describe the engine stalls when you have her at operating temp and at low RPMs. This could be oil that has thinned out and while you can get the necessary lub at higher RPMs due to the increased pressure in the oil system, once you slow down with hot oil, the "thinning" effect causes you to loose lubrication and the extra drag/friction stalls the now slow running engine. Your restart problem sounds like either the starter/battery is too hot to provide the necessary current (doubtful) or the engine has seized a bearing. Once she cools down she might just tear through the seize and operate normally till the next time she is hot and slowed down. Start listening for "bang, bang, bang" noises. They will start as "knock, knock, knock" and get rapidly (20-30 minutes) louder. They will vary with engine speed as it is the piston rod pounding against the crank bearing. The crank bearings are sacrificial and PROMPT a) stopping of the engine when the sounds occur and b) replacement of the crank bearings will save you from buying new piston rods or crankshaft. I'd say you might also want to check the cooling heat exchanger for scaling but that is a secondary issue. I've never seen an engine stop due to cooling without having steam come out of the cap first. You might want to practice up on close quarters sail handling!!!! ;-)
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