Random Yanmar instrument warning light and buzzer
- Thread starter Moondawg
- Start date
That "Water" alarm probably means "high temperature" in the engine cooling system. I can't imagine it meaning anything else. Why only sometimes many have to do with the load you are putting on the engine at the time or other variables. I would not run the engine until you sort out the cause of the alarm. As we were taught in Nulear Power School - Believe your indications!
Thanks Smokey73! I suspected as much, just not sure how to troubleshoot. I haven't had the boat very long, and this is my first diesel inboard. I'm thinking I should blow the water line with compressed air to see if anything is plugging the intake.
That looks pretty much identical to my Yanmar qm series panel, also most likely on a Cherubini if it is the original motor.
I had similar problems due to spade terminals in the wiring harness not making good contact. I took it all apart cleaned everything up and sprayed with Deoxit D5. The problem went away and due (perhaps) to a biennial repeat has never come back.
This does not mean you should not confirm there is not another issue. Over 22 years I have overhauled my heat exchanger and replaced the mixing elbow twice. Problems have come from clogs in the heat exchanger, exhaust manifold and mixing elbow. Lots of other things can go wrong too, including raw water pump and strainer.
Please tell us also whether it is fresh or raw water cooled and which Yanmar it is.
Also note that full manuals are available electronically for free.
I had similar problems due to spade terminals in the wiring harness not making good contact. I took it all apart cleaned everything up and sprayed with Deoxit D5. The problem went away and due (perhaps) to a biennial repeat has never come back.
This does not mean you should not confirm there is not another issue. Over 22 years I have overhauled my heat exchanger and replaced the mixing elbow twice. Problems have come from clogs in the heat exchanger, exhaust manifold and mixing elbow. Lots of other things can go wrong too, including raw water pump and strainer.
Please tell us also whether it is fresh or raw water cooled and which Yanmar it is.
Also note that full manuals are available electronically for free.
It's a 2QM15 with direct sea water cooling with rotary pump berthed in fresh water at Lake Travis, Austin, TX. I'll definitely clean all the contacts first. Thanks for the tip!
If it's not an electrical problem, get yourself an infrared thermometer (cheap and handy to have) - assuming you have good water flow from the exhaust, take measurements on various parts of the cooling system/engine as it warms up, should give you an idea of what's going on.
Now that we know it's a raw water cooled engine, check the following for starters :
1. Check the volume of water output from the exhaust outlet.
2. Remove the cover from the raw water pump and ensure all of the vanes are in place. Have a new gasket ready to install.
3. Remove the inlet hose from the raw water pump and have at it with your compressor.
After that, it gets a little more serious = costly.
1. Check the volume of water output from the exhaust outlet.
2. Remove the cover from the raw water pump and ensure all of the vanes are in place. Have a new gasket ready to install.
3. Remove the inlet hose from the raw water pump and have at it with your compressor.
After that, it gets a little more serious = costly.
No black soot. I 'ordered the impeller kit. Bought some 50/50 antifreeze only to find out this 2QM15 doesn't have an anti-freeze reservoir, unless it's hidden near the heat exchanger that is underneath the battery deck. Checked the oil at the top of the motor, could not feel any level of oil. Also no dipstick on the oil cap. Noticed a bunch of black oil that had come out of the two clear tubes coming down each side of the motor and draining into reservoir beneath the engine. I couldn't find any info on the oil in the online manual.
How much and what kind of oil do I use? Why would the oil be dumped like that?
Pics to follow soon.
You won’t find any reservoir for antifreeze - since the engine is raw water cooled it just circulates water from the thru hull around the block and out the exhaust. Checking that water is coming out the exhaust is definitely the first place to look. If there’s no water there you could have a closed or blocked thru hull or a failed impeller. If you’re getting a good amount of water out the exhaust you can rule out those parts of the system.
For the oil - you won’t feel oil anywhere near the fill cap. Oil runs down into the pan and only gets pumped up higher when the engine is running. The way to check the oil is with the dipstick on the side of the engine. Details are in section 12-4 of the manual at https://j30.us/files/2qm15_servicemanual.pdf but it looks like it should hold 2.5 liters of SAE 30 oil. It’s probably worth changing that and the filter if you don’t know when it was last done.
I do think you’d benefit from a book on marine diesel engine theory and maintenance. There are some periodic maintenance tasks that are necessary to keep the engine running , and some further knowledge of how the engine’s systems work will help you a lot with the troubleshooting. Nigel Calder’s Boatowner’s Mechanical and Electrical Manual has a good section on diesel engines as well as many other topics, although there may be other books that are more focused on the engine.
For the oil - you won’t feel oil anywhere near the fill cap. Oil runs down into the pan and only gets pumped up higher when the engine is running. The way to check the oil is with the dipstick on the side of the engine. Details are in section 12-4 of the manual at https://j30.us/files/2qm15_servicemanual.pdf but it looks like it should hold 2.5 liters of SAE 30 oil. It’s probably worth changing that and the filter if you don’t know when it was last done.
I do think you’d benefit from a book on marine diesel engine theory and maintenance. There are some periodic maintenance tasks that are necessary to keep the engine running , and some further knowledge of how the engine’s systems work will help you a lot with the troubleshooting. Nigel Calder’s Boatowner’s Mechanical and Electrical Manual has a good section on diesel engines as well as many other topics, although there may be other books that are more focused on the engine.
Thanks for the kind and informative reply to this diesel newbie, Davidasailor26!
The oil level was good, but the oil definitely needs changing. I ran the engine at low RPMs for about 20 minutes and took a short video of the exhaust water. I tried to remove the impeller housing but, didn't have a wrench to get up under the pulley to remove the second bolt. Here's the link to the video:
I'll definitely be checking out the Nigel Calder’s Boatowner’s Mechanical and Electrical Manual. And thank you for the link to the service manual.
Water flow looks fine for low RPM. Check the temperature of the water with your hand and let us know ............... cold, medium or hot ?
Thanks Ralph. The water was very hot when I disconnected the engine side hose from the impeller. Could it be the thermostat?
Quite likely. Your next step is to pull the stat and see what the stamped temp on it shows. You will require a new gasket to install the old or new one.
Check the downloadable section on this site and see of you can find a manual for your Yanmar 2QM15. Direct cooled engines are not my specialty.