Yanmar Water Warning Light / Buzzer

[Jack Long]

I appolgize for using the wrong term. I found it funny that the thing that sucks in salt water was called a fresh water intake.

Raw water cooling is I guess the term?

Water comes through the thru-hull, into the motor, out the other side.

Re: the exhaust

It seems you list two problems... Distance of pipe before the exhaust leaves the boat and leaving the boat below the waterline. Am I getting the right signal?

I mean no disrespect here and if that is the only solution to my problem then I am happy to at least know it- but that *will not* get fixed. That boat will not be hauled out, I will not put in a new hole, I will not arrange custom welding to modify the exhaust. If you told me, "Jack, if you do not fix the exhaust your motor will seize and become nothing but a big chunk of ballast within 30 hours of run time." I would be very careful of how I used those hours- and I would get my outboard professionally tuned up before I left... Probably bring more gas and less diesel too. Looking for something to turn into a sculling oar now.

I know the exhaust is hot. I know it travels a long way. But I have trouble imagining that the spot 8 or so feet from the motor had the hole burned in it... I haven't checked all of the stuff NewHorizon suggested so unless we have a new theory I will leave the exhaust alone for now and just patch the hole later.

NewHorizon,

When you say I need a new sending unit do you mean something that isn't part of the gauge package? I thought most of them came with this?

[Ex-Calif]

Jack - I sense you are getting frustrated. Welcome to boat ownership - :-)

You have a couple of the absolute best engine guys on the forum trying to help out.

I personally don't think you should "have" to redesign the exhaust system but if you have a hole in the exhaust somewhere there should not be a hole, it ought to get fixed. The stuff coming out of fossil fuel engines is not very people friendly.

As far as the overheating, it could be as simple as, "The fresh water has no coolant and the pressure cap is old" to as complex as the head gasket is leaking.

One thing for sure - it worked when it was new...

So what's too old?

[Jack Long]

Sorry to everyone if tension is bleeding through.

I absolutely will fix the hole in the exhaust. The context was trying to fix whatever caused the hole- and redesigning the exhaust is out of scope at this time.

Not sure what you mean about "too old"? Did I miss something in my own thread?

I actually think the dam part of the exhaust is fiberglass only- or fiberglass over rubber. It absolutely has a fiberglass wrap which I originally thought was done as insulation or something but now I think that to avoid bending a pipe they might have layered it on around a rubber tube. That tube could be coming apart and this bit of glass might just not have had enough overlap to seal...

I will stall another day or two on fixing the hole to give NewHorizon a chance to get back to me on the sending unit question. I've got plenty of other stuff to do. I agree getting an actual temperature gauge is a priority.

[Alan Wheeler]

OK, lets break this down. Sorry all the "ideas of possibles' tend to get thrown around easily, but it doesn't mean they are all problems that need sorting right away. So going to basics. The very first thing you need to do is confirm the temperature the engine is working at and getting to when working hard. I stress here that it may not be an issue at all, but simply a wrong sensor or faulty sensor that sets off the alarm. "Raw" or Salt water cooled engines tend to run colder than closed water circuit engines. Borrow a thermal measuring instrument or put a gauge in. By the way, the temp sensor should be at the front of the engine and fitted into the block or metal water pipe around the head area at the front. Yanmar experts please correct me if I am wrong!!
Next after confirming temp. Check the thermostat. Being salt water, this could be corroded and frozen up. The thermostat is found at the area the sensor is. On many engines, this is where the freshwater circultating pump/fan belt part is connected. I do not know if this particular yanmar has that pump.
Third, where the water get's injected into the exhaust, this area can block restricting water flow and thus temp controll. Remove the rubber exhaust hose from the metal part and check that it is all clear.
Do 2 and 3 in which ever order is easiest for you. But No.1 being done first will give you the information you need before any major work.

In regards to exhaust layout and design, if it has worked before, it will continue. I am not saying change it, just pointing out it ios not the best of solutions and better could be done if you so whished.

[GordMay]

Senders don’t typically fail to “inaccurate”, but (rather) to “open” or “closed”

See also “Testing Engine Gauges”: http://www.cruisersforum.com/forums/...sting-645.html
And:
Page 1: http://www.cruisersforum.com/gallery...=500&userid=79
Page 2: http://www.cruisersforum.com/gallery...=500&userid=79

[imagine2frolic]

1979 Spirit Yacht Manual - Yanmar Diesel 2QM15 Manual

Same as my 3gm. I need to go home, but will reread the thread tomorrow if you haven't solved the problem.

[Ex-Calif]

Originally Posted by Jack Long

Not sure what you mean about "too old"? Did I miss something in my own thread?

No - I wasn't clear. What I was trying to point out was that (presumably)this exhaust and cooling system worked fine for years when the boat was new.

So what parts of the system are so old that they are not working as originally intended?

- Holes in the exhaust "pipe" indicate to me that corrosion has completed its inevitable victory and entropy prevails. Maybe time for a new exhaust system - why? - You can patch the hole, maybe, but weldiing or filling something that is down the deterioration road is like chasing ghosts and eventually you will be throwing good money after bad. Or worse, fixing boats in exotic locations.

- the cooling system as Wheels points out has many "maintenance" items. pumps, impellers, thermostats, belts, heat exchangers. None of this stuff works as well as when it was new - so "what is old?" -

Sometimes we jump to - "redesign the system" a little too quickly here, but that's our nature - everything can be improved. However often it's just fixing the system that's there.

Final Advice - Think like a systems engineer. The impeller broke - what else in this system can and might break soon and while I am at it, let's fix the whole thing.

Our toilet pump broke. One thing I don't want to work on is toilets. I could buy a Jabsco pump kit and just fix that but I don't like working on toilets. So I started at the inlet through hull and finished at the outlet through hull and replaced them and everything in the system in between. I haven't had to work on the toilet for 18 months - see what I mean? Total cost was in the range of $250. So it's less than 50 cents a day so far to have a working toilet and that cost continues to fall.

[Jack Long]

Okay, so I finally finished the nightmare oil change, bought the new belts, and put the thing back together. It, of course, was still over heating/buzzing.

I removed the thermostat and it looked like hell. The mechanism still worked surprisingly smooth but it was really corroded. I also pulled the sending unit, which also looked terrible, and added a T fitting with a sending unit for a water temp gauge. I was really tickled because I went to Home Depot blind and the ONLY matched set with a male-male adapter and a female-female-female T fitting worked. Anyway, the temp gauge said specifically that it would not work with a T fitting (inside the package of course) but it worked- shrug. I did orient the T sideways so the temp gauge is at the end of a straight run.

I cleaned the thermostat up, put it back in, and ran the motor. The alarm went off when the motor hit 140 and I let it run for another 40 seconds or so and watched the gauge climb. I wanted to see if the thermostat was maybe opening late. The temp just kept climbing and so I shut the motor down.

Once it cooled down to about 100 I removed the thermostat and put it back together with the unit out. Ran the motor again for several minutes. The temp never got above 105 or so... Maybe 110. The scale on the gauge is hard to get fine data from at that level.

I called West Marine in Palo Alto and the kid who answered the phone didn't know what "Yanmar" meant and then told me they were out of stock on thermostats. I called the South San Francisco store and the girl asked the year, make, and model of the motor, put me on hold, came back and asked the horsepower, put me on hold, came back 5 minutes later appologized saying she would not forget about me and put me on hold. Total time on the call at this point was 6 and a half minutes. After a while I just put my phone on speaker and went back to work on something. Eventually she came back and immedietly started to appologize and then I saw that I had been on hold for 33 minutes and concluded our chat.

Anyway, I will track down a thermostat and a spare, load one up, and retest. But it feels like I might have found my culprit.

[imagine2frolic]

Worst Marine is not the best place for technical help anymore. That stopped when they started wearing headsets. I would just get in touch with Yanmar themselves, and they have good technical help too.................i2f

[Rodz]

JL,

West Marine does not carry engine part - I think.

Try these:
San Franicsco Boatworks 415-626 3275 SF Boat Works .Com

List Marine Inc. 415-332 5478 (Sausalito)
I would also buy seawater pump impeller and check if the heater exchanger is wet on incoming and outgoing pipes. Note that there is another pump internal to the engine that circulate the coolant and it should be checked also.

Chris

[Ex-Calif]

Good detective work!

I have several Diesel boat part on-line suppliers. The good ones have parts catalogs on-line some have manuals for your engine etc.

I don't deal with people anymore - it's too frustrating.

However all the Volvo parts, zincs etc. etc. I have ordered online have been correct and delivered promptly.

On-line ordering is also good when you are in far flung places (like Singapore - LOL)

OEM Volvo alternator belt - Singapore = $67 Online = $16 Napa "look alike" = ~$8

(I am an OEM kinda guy...)

[Gudgeon]

Jacl
Which alarm is going off my yanmar has an alarm if water is detected in the primary filter. I can't remember what it looks like. Took me a while to figure this out as it is an option on the alarm panel that I did not order but was installed anyway. If I get to the boat this weekend I will look at it. I have four alarms/idiots light temp alternator oil pressure and the water in the filter.

Mike

[scotte]

Originally Posted by Jack Long

I called West Marine in Palo Alto and the kid who answered the phone didn't know what "Yanmar" meant and then told me they were out of stock on thermostats.

No surprise there! The Palo Alto store is West Marine #1 - and they are closing that store very soon. I'm actually surprised it lasted as long as it did, since the marina in Palo Alto was forced to close 20 years ago... West Marine is opening a new store in San Carlos, it is going to be a really big store - but I doubt they will do any better for engine parts.

[Badsanta]

I have used both and have receved great advice and parts
torresen.com
mackboring.com

[nodee]

Jack,
I just joined this thread and scanned thru the previous posts. I did not see any reference to a problem I had that may relate, although I might have missed it and, if, so, my apologies for repetition.
Two years ago I was on a charter in the BVI on a FP Belize 43'. I know, different boat and actually, I can't remember what engines were on it.
Anyway, we were returning from Anegada to Marina Cay and had a water alarm sound, at least that was the idiot light indicated. We shut down, anchored and called the charter base and they sent a chase boat. Turns out the engine had a sensor that sensed high water in the engine compartment. We weren't taking on water and figured out that the crew had taken showers on the fantail and water had seeped through an unsealed deck plate for emergency tiller access. Apparently the sensor only needed to be wet, not submerged. Not sure if this fits your sympotoms or not, although I did notice in one of your prior posts that you did have water under the engine.
Anyway, the charter mechanic disconnected the sensing unit and sent us on our way as it was easier than re-bedding the deck plate. Probably not the perfect solution but good enough to finish the charter.
Anyway, just another possibility to explore. Good luck with the triage.
Cheers!
Kirk