Yanmar 3GM30F engine, burning oil--Why? Can you help?

[DeepFrz]

Here is my question, Yanmar says the engine should be good for 10,000 hours and we only had the one difficult start before a complete failure, what did we do wrong or miss to indicate that we had a serious problem?

By missed you mean? We don't have the engine anymore so can't check but interested to know what you meant?

One item you may have missed, and I'm just guessing here, is the anti-siphon valve between the heat exchanger and the injection elbow.

So what don't you understand? But because you don't have the engine any longer it really doesn't matter.

Apologies to the OP for the thread drift.

[AliOops]

I don't know, it was said we may have missed it? What about it did we miss?

[DeepFrz]

Originally Posted by AliOops

I don't know, it was said we may have missed it? What about it did we miss?

The anti siphon valve can get clogged up with salt and stop working which can allow water to rise in the exhaust system and get into the cylinders. Especially the lowest cylinder.

In thinking about this some engines have the anti siphon loop and valve prior to the heat exchanger. This is on engines that have an integral heat exchanger and very little distance between the outlet and the mixing elbow.

A new anti siphon arrangement | Sundowner Sails Again

[Matsubob]

The parts list for the 3GM30F shows a "sleeve" for each cylinder. This totally obviates the need for any kind of expensive boring. If the original sleeve is badly scored, you just replace it. Sleeves are of course too thin to bore, so you just replace the sleeve, which gives you almost the same quality as a new engine. If the piston is still usable, you retain it and replace the rings. The sleeves are chrome plated, so it takes a little longer for the rings to seat, but because of this, the sleeves can usually be honed out and reused unless they are badly corroded or scored. That would be up to the builder to decide. When I had to replace a piston, I found that it is more reasonable to buy a piston with a ring set on it than to buy the parts separately!

[sailorchic34]

Older gm engines had sleeves. In newer GM's (mid 80's ish) the sleeves were removed and a simpler bored block replaced it. It's important to know if the engine is new or old design GM engine as the pistons/rings are NOT the same size.

[ewsponberg]

Originally Posted by DeepFrz

The biggest problem with a rebuild is you still have all those old parts hanging from the engine. Alternator, starter and high pressure pump to name 3. Then there are the water pumps (both), heat exchanger and mixing elbow and maybe even the hoses. So a complete rebuild isn't very complete.

Thanks, DeepFrz. I thought about that. The alternator and starter are original as far as I can tell, and so far seem to be working properly, no direct signs of wear. So we are keeping those. Yes, we may have to replace them later, but that's later--if it ain't broke, don't fix it. The injection pump seems to be working OK, according to the mechanic, but the innards of the injectors need to be replaced. Both water pumps were new within the last year or so, as was the mixing elbow, the connector fitting to the elbow, and all the hoses and belts. So I don't need to replace those yet. Thanks for the input.

Eric

[ewsponberg]

Originally Posted by Matsubob

The parts list for the 3GM30F shows a "sleeve" for each cylinder. This totally obviates the need for any kind of expensive boring. If the original sleeve is badly scored, you just replace it. Sleeves are of course too thin to bore, so you just replace the sleeve, which gives you almost the same quality as a new engine. If the piston is still usable, you retain it and replace the rings. The sleeves are chrome plated, so it takes a little longer for the rings to seat, but because of this, the sleeves can usually be honed out and reused unless they are badly corroded or scored. That would be up to the builder to decide. When I had to replace a piston, I found that it is more reasonable to buy a piston with a ring set on it than to buy the parts separately!

and from Sailorchic34; Older gm engines had sleeves. In newer GM's (mid 80's ish) the sleeves were removed and a simpler bored block replaced it. It's important to know if the engine is new or old design GM engine as the pistons/rings are NOT the same size.

Our engine is the type that did NOT have cylinder sleeves. Therefore, the cure is to bore the engine for the new sleeves and install them. It took over a week to get the sleeves here into Puerto Rico from the States, so we lost a week in the repair. But they are here now (see photo) and the engine is being bored as this is being written. It should be ready to go back to the mechanic later this week for reassembly of all the new parts, which are in. He advises that it will be another two weeks before it will be reassembled, repainted, and ready to come back to the boat--he's a busy guy and the only Yanmar certified mechanic on this end of the island. So we have to be patient. Actually, this is really no different than our experiences in the States during the rebuild of the boat--we frequently had to prod and nudge people to get the work done that they promised. At any rate, we are pleased with progress so far.

Eric

[ewsponberg]

UPDATE 3 JULY 17: Our engine block is back from the machine shop and now has new cylinder sleeves. See photos. So today begins reassembly of the engine. The block looks to have been sand blasted, and that is because the mechanic said they were going to repaint it.

[ewsponberg]

UPDATE 8 JULY 17: Our mechanic sent in the following pictures yesterday afternoon. The pistons are in, and he is setting some of the shafts on the forward side of the engine. Everything is cleaned up and looking quite nice. I expect we'll be another week in assembly and painting.

[ewsponberg]

UPDATE 20 July 17: Today is Thursday. On Monday this week, our mechanic called to say that the engine is going back together, but that the new valves are not seating properly, so the head has to be reground to reseat the valves so that they will hold compression properly. So the engine did not come back to the boat yesterday as originally planned. The next delivery date is next Tuesday. I would have thought that he would have had the valve seat grinding done last week as he was reassembling the engine so that it could have been done simultaneously. But we don't live in a perfect world. It is not too expensive to have the extra work done, and it is only a few more days delay. Fortunately, we can handle both--we are not in a hurry, and the cost is still within our budget. At any rate, the next day our mechanic sent the next batch of pictures, of which two are below, showing the front of the engine reattached to the block. We are also going to arrange to visit his shop when the engine is all back together so that we can see it test run on the bench before we authorize releasing it to the boat.

[ewsponberg]

UPDATE 30 JULY 17: On Thursday this past week, we went to the mechanic's shop in San Juan to see the engine run for the first time since it was reassembled. It works! It has a new sound, a bit throatier (although we did not have a muffler attached), and it ran very smoothly. I attach a edited version of the video we shot. The fellow with the bald head is our mechanic, Hector Rivas, Yanmar certified. The lady in the background is my wife, Arliss.

In this video, the injectors are as original--Hector wanted to see how the engine ran first before replacing the injector tips. He was going to take care of that the next day, Friday. Also, this is a Yanmar 3GM30 engine modified to a 3GM30F. As a result, Yanmar supplied the exhaust gasket (between the head and the exhaust manifold) for the 3GM30, but that one is different than the one for the 3GM30F. So the new exhaust gasket is on order, and as of today, it will arrive tomorrow Monday. Hector will also touch up the paint on the engine over the weekend. Reinstallation of the engine into our boat will happen on Tuesday, according to the current plan. Then in a day or so we'll take the boat out for a trial run to make sure it is running smoothly under way.

I also include some still photos of the engine in the shop, plus some close-ups of the pistons and valves. Actually, the piston rings looked in good condition, but two of the pistons were badly worn. The pistons are shown in order, left to right, #1, #2, #3. Piston #1 looks pretty good, but #2 and #3 show abrasion on their side walls. The valves, shown behind the pistons, were badly caked with carbon deposits.

The total expenditure for the overhaul will come in at around $8,250 when all is said and done. We removed the engine on 29 May, and this is 30 July, so the overall time frame has been just two months for the work here in Puerto Rico. That seems about average for this region when we compare our experiences with others who have had similar work done here. Keep in mind that it has also cost us about $1200 a month just in marina fees to stay here while the work is done. So, adding $2400 for two months stay puts the total bill for this work at $10,650, roughly. I don't include other ancillary costs such as food and supplies since we would have had those anyway no matter where we were. While this cost is a big hit, our cruising budget looks to be able to absorb it, and we feel very comfortable so far with the quality of the work. Hector has answered all our questions and concerns with clear-cut information and responses, and we see that he is looking very closely at all the necessary things that one has to know to do a job like this. I certainly would not have been able to do this job myself--you need a proper shop and all the necessary tools and measuring devices to make sure all the parts go back together correctly.

Eric

[Kita]

So great info,now for the real money question is how much for a replacement new and how long for it to arrive? In the end you have a good engine but I am curious as to just replacement because I built engines in FL for years,but gas engines.... the problem I found after many years was the crate motors from the factory could offer a better warranty & could get the job done cheeper than my shop could because they have so much buying power in the parts & numbers of engines built & just put us out of business. ...as a little shop we just couldn't compete so we wound up installing engines and did fine with that but we just couldn't build them for the same price and offer that kind of warranty.

[ewsponberg]

Originally Posted by Kita

So great info,now for the real money question is how much for a replacement new and how long for it to arrive? In the end you have a good engine but I am curious as to just replacement because I built engines in FL for years,but gas engines.... the problem I found after many years was the crate motors from the factory could offer a better warranty & could get the job done cheeper than my shop could because they have so much buying power in the parts & numbers of engines built & just put us out of business. ...as a little shop we just couldn't compete so we wound up installing engines and did fine with that but we just couldn't build them for the same price and offer that kind of warranty.

Hi Kita, R&B Power wanted to sell me a new engine, which I covered earlier in this thread. That would have cost me at least $10,500 just for the engine, plus the installation costs. But the new engine would have been an electronically controlled unit that would have required rewiring part of the boat. The engine was also reversed in construction from what I have, and I am not sure it would have fit exactly right. My prop shaft is offset slightly to port. Also, the control panel was different, so the hole where my current panel is would have to be plugged up, refinished, and recut. That's new wood, epoxy, fiberglass and paint. The same could have happened to the throttle/shifter, so again, more work. Then, the horsepower and RPM would have been different, and that might have entailed changing the propeller and shaft. That means a haulout and all those associated costs and time delays.
So all that extra work would have added lots of extra cost and time. It is still much cheaper to rework the engine that I have, and I will be assured of the quality and fit of the result. In the end, the overhaul was an easy choice.

Eric

[Kita]

Understand, good call, didn’t get the part about additional mods...was just thinking direct replacement. ..I would have done the same thing! Thanks ! Good luck!

[DeepFrz]

It sounds good Eric. Now you can continue your cruise. Best of luck.