I almost fried my Yanmar 1GM Sunday. Got distracted by commotion on the dock and by pretty strong winds when casting off. Anyway, I somehow forgot to open my engine cooling water sea cock and after a few minutes of motoring out, the engine overheated and died. After realizing what I had done, I let it cool down, opened the seacock and restarted. It did start back up but belched a lot of white smoke for a minute or so. It finally settled back down and seemed to run OK with just a wisp of white smoke coming from the exhaust. Later that day I tried it several mores times and it started right up like always. The smoke has pretty much gone away and I don't hear any distressing noises from the engine and it seems (?) to be ok. Is it possbile I have seriously damaged the engine? I have always thought it was underpowered, but I am not ready to replace this engine (or even rebuild it) Comments?
Oh Crap!!
- Thread starter John5961
- Start date
- Status
Should change your raw water impeller....
as for the rest...not an expert but I think your engine will live. abe
as for the rest...not an expert but I think your engine will live. abe
new impeller..??
You probably shortened the life of your water pump impeller. If it was me I'd replace it as soon as is practical. A trick that was told to me when we bought our first sailboat with a diesel...... hang the key on the engine cooling thru-hull lever when the thru-hull is closed. If you have to put your hand on the thru-hull valve to get the key to start the engine and you still forget to open it....you have other issues
You probably shortened the life of your water pump impeller. If it was me I'd replace it as soon as is practical. A trick that was told to me when we bought our first sailboat with a diesel...... hang the key on the engine cooling thru-hull lever when the thru-hull is closed. If you have to put your hand on the thru-hull valve to get the key to start the engine and you still forget to open it....you have other issues
Outboard
I did the same thing- sort of. The water pump in my 180cc merc OB died, and she stalled 3/4 of the way out of the marina! Still had a great day, sailed about the elk river, and parked it under sailpower (proud of myself for that one) Now to get parts and rebuild the bottom end before next weekend. As for your motor- a few minutes generally doesn't get things *that* hot. In my experience, marine motors are pretty good about stalling out before meltdown temps are reached. Change your fluids and don't do it again- you'll be fine.
I did the same thing- sort of. The water pump in my 180cc merc OB died, and she stalled 3/4 of the way out of the marina! Still had a great day, sailed about the elk river, and parked it under sailpower (proud of myself for that one) Now to get parts and rebuild the bottom end before next weekend. As for your motor- a few minutes generally doesn't get things *that* hot. In my experience, marine motors are pretty good about stalling out before meltdown temps are reached. Change your fluids and don't do it again- you'll be fine.
Steam
All the white smoke was probably steam, even though you let it cool down before restarting it was still hot when that cool water hit the system. Did your "overheat" alarm go off ??? If not you should check that, otherwise you should be fine.
All the white smoke was probably steam, even though you let it cool down before restarting it was still hot when that cool water hit the system. Did your "overheat" alarm go off ??? If not you should check that, otherwise you should be fine.
Overheating
Usually if any damage was done to the engine, you'd know it pretty quickly. However, head gaskets sometimes get weak from an overheat and blow relativily short time later. So if you've used your engine say 5-10 hours and nothing happens, then I'd say your ok.
Usually if any damage was done to the engine, you'd know it pretty quickly. However, head gaskets sometimes get weak from an overheat and blow relativily short time later. So if you've used your engine say 5-10 hours and nothing happens, then I'd say your ok.
Could be worse
Recall the horror stories of sailors putting gasoline in their diesel tank or (my favorite) gasoline in the freshwater tank. You got off lucky and learned a lesson for life.
Recall the horror stories of sailors putting gasoline in their diesel tank or (my favorite) gasoline in the freshwater tank. You got off lucky and learned a lesson for life.
Amen to the impeller, Halleluiah to Yanmar
I agree with the previous post-the impeller is living on borrowered time if not dead already. Luckily it had enough fins left to re-cool the engine. So say Amen (RIP) to that impeller and get a new one. You might look into Globe "Run-Dry" impellers. They say they can run dry without crapping out. Say Halleluiah to Yanmar for being able to take the heat and restart. You probably did shorten the life span by 10 years (40 years vs 50) and it will probably use more oil than it did before (maybe a whole quart between annual oil changes) but it will probably outlast us both if you treat it nice from now on. I just would get way out until you've sea-tested for the 5-10 hours mention beforehand.
I agree with the previous post-the impeller is living on borrowered time if not dead already. Luckily it had enough fins left to re-cool the engine. So say Amen (RIP) to that impeller and get a new one. You might look into Globe "Run-Dry" impellers. They say they can run dry without crapping out. Say Halleluiah to Yanmar for being able to take the heat and restart. You probably did shorten the life span by 10 years (40 years vs 50) and it will probably use more oil than it did before (maybe a whole quart between annual oil changes) but it will probably outlast us both if you treat it nice from now on. I just would get way out until you've sea-tested for the 5-10 hours mention beforehand.
Worried?
John, If you are still worrying you could do a compression test on the engine. This will show if the cylinder head gasket has failed. If the engine didn't seize then this is normally the first thing to go. BTW what did you mean by 'died'. If it actually stopped running then I would seriously recommend a compression test as this will also check out the piston rings the bores and the valves.
John, If you are still worrying you could do a compression test on the engine. This will show if the cylinder head gasket has failed. If the engine didn't seize then this is normally the first thing to go. BTW what did you mean by 'died'. If it actually stopped running then I would seriously recommend a compression test as this will also check out the piston rings the bores and the valves.
Insurance, when I close
the raw water intake I hang the boat keys from the alternator belt so when I have to retreive them I will know to open the seacock. This is cheap insurance.
the raw water intake I hang the boat keys from the alternator belt so when I have to retreive them I will know to open the seacock. This is cheap insurance.
Diesel Engines are Tough
Yanmar engines are very forgiving. It usually takes more than a few minute operation without cooling to hurt the engines. The pistons and rings allow for expansion due to temperature increases. I would definetly change the impeller in the water pump though.
Yanmar engines are very forgiving. It usually takes more than a few minute operation without cooling to hurt the engines. The pistons and rings allow for expansion due to temperature increases. I would definetly change the impeller in the water pump though.
Hi John, I'm not sure about your engine model...
but I know our Onan Genset has a heat sensor on the mixing elbow, which will shut the engine off when the exhaust gases reach a certain temperature in the absence of elbow cooling water. Terry
but I know our Onan Genset has a heat sensor on the mixing elbow, which will shut the engine off when the exhaust gases reach a certain temperature in the absence of elbow cooling water. Terry
Donalex
Your a good man but I have to disagree. Gaskets are made of flexible material. They weaken easily from heat. A compression test will only measure the air that is escaping from the cylinder at that time. When a gasket goes, it goes because it breaks at that time. In other words, a gasket is good up until the split second it decides to not be good anymore and you will loose at least 1/2 of your horsepower and the engine will overheat. I used to be a diesel mechanic and had to replace lots of head gaskets. I made it a habit to ask the operator the short term history of the vechile before hand. Many times it had just overheated within a couple of weeks.
Your a good man but I have to disagree. Gaskets are made of flexible material. They weaken easily from heat. A compression test will only measure the air that is escaping from the cylinder at that time. When a gasket goes, it goes because it breaks at that time. In other words, a gasket is good up until the split second it decides to not be good anymore and you will loose at least 1/2 of your horsepower and the engine will overheat. I used to be a diesel mechanic and had to replace lots of head gaskets. I made it a habit to ask the operator the short term history of the vechile before hand. Many times it had just overheated within a couple of weeks.
Thanks for the feedback
Sounds like there is a consensus on changing the impeller. I guess since it's rubber, the heat does a number on it. I'll look for one on line. I went to the lake last evening after work and cranked the engine. It started immediately, no smoke, and ran fine for several minutes before I shut it off. Looked like it was pumping plenty of water out the discharge. I also noticed that the engine is an SVE (or SV8). I'm thinking that isn't the same as a 1GM. The previous owner had 2 manuals. One for an SV8 /SB8 and another for the 1GM, so for some obscure reason I assumed it was the IGM. I guess I need to do an Internet search for this model impeller. Hopefully it will be easy to find. I passed on buying another Hunter 27 that looked pretty good because it had the Renault diesel which has been out of production forever.... Again, thanks to everyone for the encouraging words. Oh yeah, I like Cap'n Steve and Benny's suggestion about where to hang the key.
Sounds like there is a consensus on changing the impeller. I guess since it's rubber, the heat does a number on it. I'll look for one on line. I went to the lake last evening after work and cranked the engine. It started immediately, no smoke, and ran fine for several minutes before I shut it off. Looked like it was pumping plenty of water out the discharge. I also noticed that the engine is an SVE (or SV8). I'm thinking that isn't the same as a 1GM. The previous owner had 2 manuals. One for an SV8 /SB8 and another for the 1GM, so for some obscure reason I assumed it was the IGM. I guess I need to do an Internet search for this model impeller. Hopefully it will be easy to find. I passed on buying another Hunter 27 that looked pretty good because it had the Renault diesel which has been out of production forever.... Again, thanks to everyone for the encouraging words. Oh yeah, I like Cap'n Steve and Benny's suggestion about where to hang the key.
Hrs. of use?
Oh yeah, I meant to comment on the 5-10 hrs of use. That made me smile a little. I typically crank the diesel, motor out of the marina and raise the sails. Coming back, I sail almost up to the no wake zone, crank up and motor in. I doubt I've ran it for 2 hours all summer. One of the few benefits of lake sailing. No schedules to keep and nowhere you have to be so you can take your time. Plus the poor thing is so underpowered, motoring is almost painful. Now if I were on the intercoastal, I'm sure it would be a very differant story since I would probably have to motor a lot more than sail.
Oh yeah, I meant to comment on the 5-10 hrs of use. That made me smile a little. I typically crank the diesel, motor out of the marina and raise the sails. Coming back, I sail almost up to the no wake zone, crank up and motor in. I doubt I've ran it for 2 hours all summer. One of the few benefits of lake sailing. No schedules to keep and nowhere you have to be so you can take your time. Plus the poor thing is so underpowered, motoring is almost painful. Now if I were on the intercoastal, I'm sure it would be a very differant story since I would probably have to motor a lot more than sail.
Impeller insurance
Changing your impeller is cheap insurance. I purchased my boat and did not change out the impeller; caught some duck weed in the intake and the motor overheated. The impeller came apart in little pieces and the cost was triple to have the engine flushed and a new impeller. Now I keep a spare onboard and check the impeller at the beginning of each season. A new impeller is cheap insurance.
Changing your impeller is cheap insurance. I purchased my boat and did not change out the impeller; caught some duck weed in the intake and the motor overheated. The impeller came apart in little pieces and the cost was triple to have the engine flushed and a new impeller. Now I keep a spare onboard and check the impeller at the beginning of each season. A new impeller is cheap insurance.
Diesels need to be used...
Since diesel engines do not run at the higher temperatures of their gasoline cousins, their ability to self-clean is somewhat compromised. Therefore, it is a good practice to periodically put at least thirty minutes of continuous crusing speed runtime on your engine. Being a lake sailor too, I know how you can get into that 5-10 minutes of operation habit.
Since diesel engines do not run at the higher temperatures of their gasoline cousins, their ability to self-clean is somewhat compromised. Therefore, it is a good practice to periodically put at least thirty minutes of continuous crusing speed runtime on your engine. Being a lake sailor too, I know how you can get into that 5-10 minutes of operation habit.
Follow up on "Oh CRAP"
Good advice on the impeller check and running the diesel longer. This weekend I did check on my impeller and it was fine. no signs of wear and flexable with no deterioration. I am ordering a spare just in case.
Good advice on the impeller check and running the diesel longer. This weekend I did check on my impeller and it was fine. no signs of wear and flexable with no deterioration. I am ordering a spare just in case.
- Status