33yr old Yanmar GM30F...?

[Babylon]

Looking at a boat which has its original Yanmar GM30F, owner maintained for the last decade or so, engine hours completely unknown (a totally wild guess of say 75hrs a year gets it to about 2,500hrs, but maybe it has more?).

What can one realistically expect from such an old and well-used engine over the next few years? I anticipate an ownership period for me of say 10-15yrs, including a rolling-programme of renewing stuff (e.g. standing-rigging to start with) and improving/adding other things.

Get to know it, nurse it along? Maybe get to a point (perhaps sooner rather than later?) where it needs either a rebuild (low cost option) or a complete new replacement?

 

[IanCC]

Pay good money to an engineer to go over it. It could be good.
Or read Nigel Calders book. It has a section on how to survey the engine.

 

[vyv_cox]

My Yanmar 3GM30F has done nearly 2800 hours. Bought in about 2000. It looks new, is still on its original hoses, second set of belts, second water pump. It starts first time, runs perfectly and uses little oil. I know of similar engines that have done 15,000 hours, still going strong.

 

[jwfrary]

Fine engines all the parts are still availible and they are built heavier than any of the modern engines that replace it.

Normal things like heat exchanger cleaning and water pump seal replacement is probably due. Valve stem seals possibly but all easy jobs and they are easy engine to work on.

 

[Babylon]

Thanks for the replies, most reassuring.

Useful suggestion also to have an engineer take a good look at it, as I'm handy enough with servicing etc but no more knowledgable than that. If I go for the boat my offer will be subject to survey as usual, but also perhaps an engineer's report. I just don't want to find myself lumped with a very big bill for a replacement after a couple of years - which is what happened when I bought my first boat!

 

[jwfrary]

Thanks for the replies, most reassuring.

Useful suggestion also to have an engineer take a good look at it, as I'm handy enough with servicing etc but no more knowledgable than that. If I go for the boat my offer will be subject to survey as usual, but also perhaps an engineer's report. I just don't want to find myself lumped with a very big bill for a replacement after a couple of years - which is what happened when I bought my first boat!

We can't tell you it's not going to have a catastrophic failure, but they are robust, and if we'll installed and serviced it should give plenty of useful service life.

Mines going on for 4000 hours shortly

 

[sailoppopotamus]

I have a 2GM20F from 1988 on my boat, engine hours unknown. It's got a few oil leaks here and there which I'm addressing one at a time, but otherwise starts and runs fine. I've been working on it bit-by-bit as I go along, mostly preventative maintenance. There is the option of getting an engineer to look at it, as some have suggested. I didn't do this when I bought the boat, but brought one on a couple of months later. He wasn't helpful at all -- told me the engine is tired, and wanted to pull it from the boat and tear it apart. This would've cost at least a couple of thousand, and since the engine was running fine I declined. If you do buy it, I would highly recommend you replace all belts and hoses, in addition to the standard maintenance items (oil filter, fuel filter, impeller, oil change, coolant change, transmission oil change). I also had to get the starter motor rebuilt.

Without being an expert on engines, and picking up DIY skills as I go along, I think it's a well made engine that will last for a while. It's easy to work on, the manuals are good, and it's such a popular engine that whatever problem you might have with it, someone on the internet has already had it. I've had no difficulty finding spare parts, even slightly obscure ones, and they are generally reasonably priced (with a few exceptions). I have a friend with a Volvo engine and, seeing what he pays for parts, I'm very grateful for the Yanmar.

As others have said, try to get an engineer that is willing to do an inspection, otherwise do one yourself. There are some red flags that would make me look elsewhere: difficulty starting, water in the oil, anything but coolant in the coolant, excessive smoke.

Realistically, unless you can find a boat with a new engine (unlikely), you'll have to deal with a used diesel as part of the boat owning experience. And in this respect my humble opinion is that you would be lucky to have a 3GM30F over any other engine.

 

[Babylon]

Thanks Sailoppopotamus - further reassurance!

 

[sailoppopotamus]

Happy to be of assistance. Just a few more thoughts: parts availability/pricing is not the same in all countries. Yanmar only sells parts to their authorized distributor, so their price/availability is very much dependent on your location. I live in Greece, and have only excellent things to say about their distributor here -- longest I've ever waited for a part has been 48 hours. From what I read, in places like New Zealand/Australia it's a completely different experience. Hopefully the UK-based members of the forum will chime in with their views on parts availability in the UK (assuming this is where you'll be keeping the boat).

I'll take the opportunity to reiterate my advice to change all hoses, on whatever boat you buy with an old engine. The hose between the filter and injector pump sprung a leak on me, and I was really lucky to have enough fuel to make it to the nearest marina with a bilge full of diesel. Perhaps also a testament to how resilient these things are -- diesel was spraying all over the place but it chugged on completely unfazed, and with no noticeable loss of performance.

 

[Babylon]

Also good advice, thanks.

I guess that, although messy, the reason your engine didn't miss a beat was because the leak was on the low-pressure side of the system.

 

[38mess]

As long as it starts promptly, doesn't smoke, make strange noises, gets up to revs and the oil looks good, and no sludge in the coolant it will be fine. I think the spares availability for this engine is still good.

 

[Blueboatman]

As long as it starts promptly, doesn't smoke, make strange noises, gets up to revs and the oil looks good, and no sludge in the coolant it will be fine. I think the spares availability for this engine is still good.

Yup
This very question came up recently on here and conclusions were just that .
Maybe it’s the same boat for sale ?

 

[vas]

mind, yanmar GM series, do make a hell of a noise and are often considered to be just sort of falling apart when they're just fine

 

[Lightwave395]

I replaced my 26 year old 3GM30 a few years ago, it did everything I asked of it except starting cold when I had to talk to it very nicely... for the first 20 seconds when it did start, clouds of various coloured smoke emerged but once it settled down it ran like clockwork and used hardly any oil, or diesel come to that. I had the injectors refurbished and various other things but it still didn't like starting after being left for a few weeks.
I confess I only replaced it having been offered a 3YM30 with 50 hours on it, which runs like a dream and certainly seems quieter than I remember the 3GM to be

 

[zulloboy]

My 2GM is over 40 years old, with about 2500 hours on the clock, starts within a second or two at idle throttle down to 5 degrees, and it runs beautifully. As already said, if it starts and runs ok , your chances are very good.

Cheers, Graeme

 

[Buck Turgidson]

My QM is at least 45 years old. Purrs like a kitten.

 

[Babylon]

All good reports thanks. The vendor says his particular engine needs "TLC"...