Yanmar 3GM30F Preventative Maintenance

[Snowgoose71]

Hello - I have a 1998 Beneteau 352 (owned for 7 years) which I used to live on and did near-shore cruising and racing. I have been doing more offshore (40-50) miles off lately and well it has given me a new appreciation for engines, systems, sails, etc and making sure EVERYTHING is in good working order....

So, I've made a list and one area is the cooling system for my Yanmar. I have recently replaced the seawater pump and belt. I inquired about an estimate for replacing the thermostat, radiator cap, freshwater/coolant pump, and possibly the hoses (and inspection of the heat exhcanger).....

What I got back was if it aint broke don't fix it mentality....I meant the mechanic said he would do what I want but felt that there is no need to replace the thermostat, coolant pump, radiator cap, or even inspect the exchanger. He did say he'd look at the coolant and if it looks like rust he would flush but otherwise he thought just a drain/refill would be ok.

Would appreciate thoughts and opinions....as said I have had boat for 7 years and I know I haven't changed coolant, thermostat, nor the hoses. I'm not sure of the life of these components...

Robert

[NYSail]

Well I rely on my engine (yanmar 4JH4E) so I do things prior to them breaking. That being said when I got my new boat, first thing I did was get all brand new hoses, fresh and sea water, new thermostat, radiator cap (old one was rusty), new fuel lines, flushed the cooling system thoroughly, changed all filters, upgraded primary fuel filter (racor 500), changed all filters, oil and transmission fluid. I inspected my mixing elbow and did a good inspection of the engine. Did this on my last engine I’m old boat (yanmar 3HM35f) also. I dont go so far as replacing pumps if they are working, however not opposed to buying one and having a spare. And all the stuff I mentioned is stuff you can do yourself. Keep the engine clean, run them hard, change fluids and filters yearly and these engines will last and treat you well. I change oil and transmission fluid every year, coolant every other.

Good luck!
Greg

[AA3JY]

Start collecting the spares as mentioned and learn if not already how to replace them..especially in a seaway..when it’s pitch black..and with a hot engine..if need be..

[Wotname]

A good place to start is to carry out the preventative maintenance in accordance with the schedule set out in the Yanmar manual.

There are only two types of maintenance - scheduled and unscheduled.

With scheduled maintenance (i.e. preventative maintenance) you get to choose the time and place to adjust / replace items on the engine.

With unscheduled maintenance (i.e. fix it only when it breaks), the engine gets to decide the time and place.

I have found the engine never chooses a convenient and place to breakdown so I prefer the other option where I get to decide the time and place.

Your mechanic isn't going to come to you if the engine fails at sea - you either have to fix it or sail home or get a tow. I personally wouldn't take his advice to wait 'til it breaks but YMMV.

[gamayun]

Oh, good on you! What fun. Seriously. I don't understand how anyone can give up their engine maintenance to someone else. I also have a 3GM30F, but it is a 1988 model that I've owned for 8 years. Over the years, I've pretty much done everything that NYSail did. Most recently was the upgraded Raycor and fuel pump. I've bought a new mixing elbow that I will replace soon because the other one is looking a bit corroded. Why worry, you know? I also replaced the injectors last year. That was probably the most "complicated" and it actually turned out to be fairly straightforward and simple. The hard part for me is when things get stuck. I tend to be the type to reach for a bigger crowbar and hammer. Aerokroil and heat are your friends. If you have never done any of the maintenance yourself before now, and you don't know anything about what the POs did, then my advice is to start with all the fluids first (including filters) and then change the impellor and hoses. Alternatively, you could remove the hose clamps and inspect the ends because this is where they seem to deteriorate the most, but why not start fresh in your log book. If the water pump is not leaking, then no need to replace, but if you have plans for offshore, then a spare would be good. I have not removed the heat exchanger but I have inspected all the holes to make sure there was nothing clogging the water flow. Old impellor blades can be found in there. Oh, I also upgraded to the 100 amp Balmar. Now that was one complicated project! A friend helped me when we did the Raycor and I almost lost my mind on the wiring. I must have started to block out that project. Theoretically, I could hook up the old 50 amp alternator if the 100 amp ever goes, but I am keeping my fingers crossed I will never have to do that. When you get to that stage of the game, find a friend or good mechanic who knows what they're doing and won't cut corners to "make things work" and keep the Balmar tech number handy when something doesn't make sense. There's still stuff I need to learn, but if you got all that down, you should be able to handle anything that comes up offshore. Good fuel and a solid systems means less to wrong too. Of course, you do know how to bleed it, right? If not, the fuel filter change will be a good teachable moment for that

[Compass790]

I'm in the inspect it camp, if you know what you are looking at
I think Yanmars replacement schedule is a bit OTT. Eg they say, for our engine, replace hoses every 4 years. Well I replaced the original fuel line from the filter to the fuel pump at 36 years but that was a few years too long as it crumbled pulling it off. My 93 toyota has the original radiator hoses. Just done the original water pump at about 300,000km
However I'd stick to the oil, filters & anode change schedules if it has them.
Good idea to clean heat exchanger
Think spare raw water pump is a good idea & you need to know the things gayamun suggested if you don't want to get towed sometime.
But starting with all new stuff for peace of mind may suit you better.
Personally I think it's essential to have enough mechanical skills to do all that basic stuff as help wont necessarily come fast enough.

[Frankly]

I have owned a 2GM and 3GM for a total of 40 boat years. PM type maintenance: mixing elbows replaced every 4 or 5 years, new raw water pump impeller every few years, new engine fuel pump every 10 to 12 years, clean heat exchanger tubes every 4 or 5 years (32 cal brass pistol brush), that is about all I recall. Carry lots of spares, changed circulating water pump in Waderick Wells, Florida Keys, and sea water pump in Tarpon Springs. Spare starter motor, spare Balmar alt and regulator, complete spare SW pump (sometimes the problem is seal and bearings), belts, gaskets, hoses, filters ect.

Never needed a tow, learn to take care of the engine yourself (they are great little engines), your life will be better (only Yanmar mechanic in Waderick Wells is going to be you or maybe another skipper ain't no Sea Tow).


Frankly

[Snowgoose71]

Thanks for the responses...and yes I am learning how to do some basic maintenance like oil changes and did my first fuel filter change a week ago...unfortunately the butterfly valve on the fuel lifter broke off so I'm having that replaced!

I did have the exhaust elbow replaced about 3 years ago so good with that. The raw water pump is new as is the impeller....so I want to finish up the coolant side of the process this year and next year I'll focus on the fuel systems to include: fuel lines, fuel injection nozzles, and perhaps a fuel pump (one of you said to change every 10-12 years).

I have not changed transmission fluid....however, at the end of this year when I haul out of the water I do plan on replacing the prop shaft. Assume the fluid would need to be replaced with the shaft replacement?

Anyway...I'm trying to be more preventative/scheduled.

[kmcshane]

One preventive item that I do for my 3GM30F is to flush the raw water side using fresh water with the engine running. I leave Florida for the Summer, I don't want salt water sitting on all the componenets: impeller and water pump, the heat exchanger, the mixing elbow and muffler and all the hoses.

When I return, I still remove and replace the impeller and use some olive oil on the tangs.

A friend suggested using the correct dilution of Barnacle Buster, which he said shot our a bunch of crap when he started his engine back up. Mine, not so much of anything, so that's debatable. I think I would do it in your case just to see if it spit anything ugly out.

[NorthCoastJoe]

I have a 3GM30F, I do of the above ... Change the transmission oil when you change engine oil.

[George DuBose]

I just posted a question about maintenance schedules to my Pearson blog as I am preparing to leave my European home base for around 5-7 years and will be leaving my support base of my mechanic and my electrician so I am trying to gather the appropriate spares to avoid the hassle of trying to find the parts when I am on tour.

My 2005 Yanmar 3GM30F has 2000 hours on it, changed the engine water pump last year and had the heat exchanger reamed, but what about a valve adjustment? Should I carry rebuilt or new injectors?

belts
all filters
extra raw water pump and impellers
extra starter
extra exhaust elbow in stainless?

I will be changing all the hoses, including the 15 year old exhaust hose, but what about the waterlift muffler? Does that need servicing, draining or cleaning?

[Compass790]

It depends a bit on how many hours you anticipate putting on it whilst you are away.
I'd want at least one spare injector & a spare ss exhaust elbow is a good plan.
Ask your mechanic when valve clearances were last set but if you cant do it & it hasnt been done say within 200 hrs it would pay to check.
Spare alternator voltage regulator if you don't have an external smart regulator.
Spare fuel pump, doesnt have to be gold plated Yanmar one. You can add a 12v low pressure flow thru type to your fuel system. Makes bleeding a helluva lot easier.

If your waterlift muffler is a plastic box it doesnt need anything done AFAIK

[Snowgoose71]

One more thing.....how many hoses are there in the cooling circuit (raw and coolant side) and how much should I expect to pay for new ones? If I buy new hoses do I need to still do a flush of the system with barnacle buster (raw) or would inspecting the heat exchanger be sufficient with the new hoses?

[fcallard]

My 3GM30F is 1990 vintage and we’ve had it for 24 years. Maintenance over the years included replacing hoses on a PM basis, replacing exhaust elbow, changing oil every year (regardless of low hours per season). The biggest maintenance issue has been the raw water pump, which I have had completely rebuilt after a seal failure caused by a scored shaft (missed by the first guy that rebuilt it the first time.) I have also added a Speedseal kit to the pump to make access to the impeller easier and to extend the run dry time (which you want to minimize, of course.)

I took the Mack Boring diesel maintenance course and a major take-away was the importance of getting your engine to operating temperature. They suggested to run it Periodically under load for several hours (e.g. deliberately motoring somewhere) if you don’t normally run it long enough normally.

BTW, my 30 year old engine has about 1400 hrs and seemingly will go on forever.

[Snowgoose71]

Originally Posted by fcallard

My 3GM30F is 1990 vintage and we’ve had it for 24 years. Maintenance over the years included replacing hoses on a PM basis, replacing exhaust elbow, changing oil every year (regardless of low hours per season). The biggest maintenance issue has been the raw water pump, which I have had completely rebuilt after a seal failure caused by a scored shaft

BTW, my 30 year old engine has about 1400 hrs and seemingly will go on forever.

Sorry for naive question but assume when you say shaft that you mean there is a shaft inside the pump (not talking about the prop shaft?). If so, how does that impact the seal.....I ask because my raw water pump was spraying water and I just had it replaced about a month ago.