redtim

1GM10 burning oil. Problem? Not a problem?

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My situation

the 1gm10 came with the boat. In its past life, the PO had all the oil fall out and an alarm failure, so he bricked the old block.  He found a used block, machined the head, mated the two and off she went. The problem is, now the engine burns some oil.  Not a whole lot, say around a quart every 10/20 hours, but the engine only holds 1.5 quarts, so I'm doing a lot of refilling.  I was sort of content to just live with it and be mindful of the oil level but yesterday I changed the oil filter for the first time after about a year, Shitty access and such,  but after an accidental flush and an hour or so of running through the rpms the oil is still squeaky clean.  I assumed that the oil was getting past the rings and burning, and that if that was happening, soot would be getting into the oil, turning it black fairly quickly but maybe that's not how it works? 

Any thoughts? The clean oil piece is giving me some hope that maybe its an issue that wouldn't require a full rebuild? Is that just wishful thinking? Any ideas on what else might be going on here?

 

 

 

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Compression test?

First thing I'd do if I suspected internal leakage. It could be getting past the valve seals as well.

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No compression test yet. 

The engine starts pretty easily and revs to its limit no problem, and doesn't seem to have any power issues. 

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Unless there's a big puddle of oil under the engine then its almost certainly burning it, you'd know if the head gasket had gone and it oil was getting into the seawater you'd see it with the engine running at the dock.
Personally I'd just keep topping it up, since fixing it will probably necessitate a rebuild, if it was something easy like a seal then you'd have oil under / on the engine.

If you do want to know more then as Jon said, a compression test is probably the next stop.

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Thanks. 

You're right, no sheen at the dock, no oil under the engine. 

I guess keeping adding oil is the easiest of the fixes. 

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I spoke to a Yanmar person in San Francisco who sold parts for decades. I purchased new valve seals because our 3GM was burning oil. She said forget them; it's not the valve seals. She said she never sold them because it just doesn't leak oil there. But she was happy to take my money in case she was wrong.

My engine had been babied by the previous owner (run at 2000 RPM all the time) and the bores were a bit polished. I ran it hard 3400 for a few hours, 3600 RPM for 1 hour and this reduced the oil consumption considerably. Mine used to use about 1 L every 15-20 hours.

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3 hours ago, Zonker said:

I spoke to a Yanmar person in San Francisco who sold parts for decades. I purchased new valve seals because our 3GM was burning oil. She said forget them; it's not the valve seals. She said she never sold them because it just doesn't leak oil there. But she was happy to take my money in case she was wrong.

My engine had been babied by the previous owner (run at 2000 RPM all the time) and the bores were a bit polished. I ran it hard 3400 for a few hours, 3600 RPM for 1 hour and this reduced the oil consumption considerably. Mine used to use about 1 L every 15-20 hours.

Dunno why this is so hard to do... but it is.

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T

2 hours ago, Ukuri said:

https://costeffective.com.au/

You may find some of the info here helpful. I have used some of their products on my old Fiat 615 tractor and had great results. 

Thanks, I'll take a look

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5 hours ago, Zonker said:

I spoke to a Yanmar person in San Francisco who sold parts for decades. I purchased new valve seals because our 3GM was burning oil. She said forget them; it's not the valve seals. She said she never sold them because it just doesn't leak oil there. But she was happy to take my money in case she was wrong.

My engine had been babied by the previous owner (run at 2000 RPM all the time) and the bores were a bit polished. I ran it hard 3400 for a few hours, 3600 RPM for 1 hour and this reduced the oil consumption considerably. Mine used to use about 1 L every 15-20 hours.

I run at ~3200 anything less is painfully slow.  I'll give it a go at 3600 for a while, see how that shakes out.

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11 minutes ago, redtim said:

I used some of this stuff

https://www.restoreusa.com/index.php

didn't seem to have much or any effect

I just had a look at the Restore website and it seems that the two products, CEM and RESTORE, are formulated with different ends in mind. I'm a bit sceptical that you can "chemically" repair a worn engine as RESTORE seems to claim. 

As I understand it CEM is formulated to remove the deposits left behind when the engine is run at low loads and under optimum temp. As others have said a good, hard, full operating temperature, run should achieve the same end. It wasn't cheap and was sold as a three part treatment, one to add to the oil prior to changing. One to add to the fuel. And one to add to the new oil after an initial clean wit a double change using the first product. 

 

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A compression test is not going to prove much because it's most likely oil control rings that are suffering rather than the compression rings, if it is starting ok. It is using a lot of oil for the small sump and practically emptying it in the time you say. Engine overhaul may be the only longterm option.

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Some ring leakage is caused by carbon (burned oil) jamming up the rings so they don't seal vertically. The solvents for carbon are concentrated sulfuric acid or hydrogen peroxide. Neither are very good for an engine :-)

Other leakage is from cylinder glazing. If the rings and piston flying up and down doesn't remove glazing I doubt any snake oil will. That idea, above, of running at high rpm might well work.

If cleaning rings and restoring the cylinder walls is desired it is a relatively simple matter to tear down the engine just for that. Especially so with a one-lung engine. Put all the same parts back in. Used to be standard procedure back in the good old days. A morning job for a shadetree guy like me.

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1 hour ago, Zonker said:

Magic potions usually don't - you have to BELIEVE for them to work.

I agree but I've heard praise for Sea-Foam from mechanics I respect.

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There are a couple shade tree mechanics who have gotten gunked up old truck engines running a lot better using seafoam in the gas, in the oil (prior to a change/flush) and with a spray that goes up the air intake.  There are a few tales like this with YouTube videos to match... Never tried that approach with a diesel but it's my go-to for keeping diesel gunk and water in the fuel to a minimum. 

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I use Sea Foam as a fuel stabilizer for gasoline, among other things. Works well as an ongoing carburetor cleaner too. 

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one thing that did actually help my little 2gm was was this catalyst for injectors, I put in a strong decoking dose and to my surprise the damn thing stopped putting out so much black smoke. probably not going to help you but my engine has a lot of hours and burns about no oil.

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You can also pull the injectors very easily and take them to an injector shop for a cleaning. It's usually pretty reasonable in cost.

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If the head has a history of being run without oil you may have some slop between the valves and the valve guides, even if oil leakage in the head is not ordinarily a problem on these engines.

On a diesel oil leakage past the valves is unlikely to result in any follow-on problems unless you run out of oil (though this is a real risk).  On a gasser it would foul the plugs.

You could pull the head and overhaul it but I am unsure whether that would be a wise use of funds and labor on an older 1 banger.

As for the magick potions, well, save your money

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Well i took the "run it hard" advice, ran for about an hour and a half at 3600, all was good, but burned through about half the dipstick worth of oil.  And developed another symptom, when i got to idle after running at 3600 for the duration, the oil pressure alarm started chirping just a bit. 

So what to do? 

Repower? a beta 14 is ~8k plus whatever in parts to make it work.  the beta dealer around here gave an estimate of 50 hours to install it, all in looking at close to $20k to repower. figuring it will take me 2x as long as them to do it myself, 100 hours is out of the question

Rebuild?  I've never rebuilt an engine, this one seems like an easy enough project, but with the learning curve i'll have to deal with an engineless boat for a couple months, no engine means missed races, not willing to do that after missing so many last year.

Find a  new/rebuilt 1gm10? for such popular engine, i figured there would be more of these, but outside of one rebuilt engine in Lithuania, i can't find anything other than sketchy ebay listings.   

I'm almost at the point of repowering with electric, but i need at least 15 miles range at good speed to get to the start line for our races, even with lithium, that's not a great option for weight.  

I guess keeping a jug of oil around is the cheapest option i have

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How about buying a used 1gm, rebuilding that, then swapping? Should be able to find one cheap, you can reuse your known-good accessories, minimal boat downtime.

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7 minutes ago, andykane said:

How about buying a used 1gm, rebuilding that, then swapping? Should be able to find one cheap, you can reuse your known-good accessories, minimal boat downtime.

I'm open to that

this one is a candidate, https://www.ebay.com/i/303649775730?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=303649775730&targetid=1068323855470&device=c&mktype=pla&googleloc=9032064&poi=&campaignid=10897980201&mkgroupid=114065841584&rlsatarget=aud-762207186714:pla-1068323855470&abcId=9300403&merchantid=102010203&gclid=CjwKCAiA_eb-BRB2EiwAGBnXXiIOPfZWq27BHt6BQiykFbMnAo9Casn88yGdsdYLsfGI_UBz-tBiTRoCHJAQAvD_BwE

though i'm skeptical of the seller, it was originally listed as for a saildrive until I asked him about it.  I'm really surprised I can't find something closer.

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I've seen a couple of these here and there. My thought is to continue with the oil til you find a rebuild candidate. There are piles of these somewhere in a consignment shop, a marine flea market. I presume you've  tried Sailorman, but there are many more small shops in every big boat town. Worse case is buy a used Hunter 27 or similar just for the engine. 

More diligence.

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Re: the rebuild route - find a diesel mechanic who will babysit you through a rebuild. I did that with a Hi Po Chevy engine and it worked great. His time cost little - 3 figures and it ensured I did things right.

Doing it yourself is very gratifying - the first time it lights is absolutely exhilarating plus you know every inch of the engine.

I've swapped engines in boats and cars - the "extras" really add up - if you get away with 25% of the engine cost you're doing extremely well.

I did a "like for like" swap years ago - a Yanmar YSM8 replacing a YSE8 - they were basically identical, the M was just an upgraded E and it still cost about 20% of the engine cost. Hoses and fittings and mounts and fasteners and solvents and paint and... and... add up quickly.

Ask around the boatyards and marine mechanical places for used engines. They know most of what's out there.

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I think you're jumping the gun here. If your hard run successfully re-seated the rings and broke the glaze on the cylinders, your oil consumption hopefully dropped at some point during the test. Change the oil and start using the motor as you normally would. My guess is that the low pressure chirp was due to low oil volume and very hot oil from the test. My further guess is that you won't see the chirp under normal circumstances and that you bought yourself some time with the hard run.

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... Has a 1 cylinder yanmar 1gm 9hp diesel motor but had been sitting in water in the freshwater bilge for a bit and need a very serious going over / replacement not sure but prop is brand new and not cheap. My buddy has a 83 1gm that is complete but in pieces that he will sell as is for $500 so you got that option.

https://mobile.craigslist.org/boa/d/pensacola-24-project-tug-trawler/7242072500.html

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No you do not want an engine that has been half submerged for any period of time. 

I would certainly change the oil right now. You may have dislodged some old gunk in the oil passages. The low oil pressure chirp might have been due to low oil and the pickup sucking air for a brief moment. Keep on topping it up for now.

Rebuild:

This guy rebuild a 2GM in his cockpit. If you have access to a garage, workshop, proper tools, and easy parts availability from the local Yamar dealer you will have it SOOO much easier than he did. Also you have only 1 cylinder so half as much work.

Part 1:  https://youtu.be/4mKjUBF_5kY?t=524

With very basic tools

image.thumb.png.3bced6049f21548f904601b730b3602a.png

he uses a block of wood and a wrench instead of a valve spring compression tool that YOU can rent / borrow from your local auto part store

image.thumb.png.2de46b0503af9231b6d9733babd0ce01.png

I didn't know that the GM series use cylinder liners. That makes your life a lot easier. No need to overbore and use larger pistons.

 

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Push pause until you are sure what's what. Pull your oil pressure sending unit blow it out make sure no gunk. Keep the pan full and see how it goes.  The initial oil consumption points to rings or glazing as above or who knows what at some point that might have caused sticky rings. Checking the valve lash is super easy and something to check even if unlikely.  A new one is probably way more than a rebuild, if you have time and space doing a rebuild now probably worth it. A good excuse to buy tools!!

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Thanks for the advice all.  those videos make the rebuild look a lot less intimidating than I expected.  I also found another 1gm10 locally on craigslist, Hoping i can get over to check it out this week.  I like the rebuild one while the other is in the boat idea.

 

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I took a look at the shop manual today, looks like the 1gm is sleeved, the 1gm10 is not.  That makes a rebuild less palatable. 

I did find another engine locally thats "running" but the oil consumption on mine seems to have dropped considerably, i've run the thing for an hour or so and i don't notice any oil missing, I'm sure its not solved so i'm still thinking about picking up the used engine, maybe rebuilding it over the winter. Could be a fun project? Maybe it won't need a rebuild and it will be a Christmas miracle.

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5 hours ago, redtim said:

I took a look at the shop manual today, looks like the 1gm is sleeved, the 1gm10 is not.  That makes a rebuild less palatable. 

Either way you'll need the machine shop. May as well have them boil the block out, do the valve job, resurface the block and head too. 

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6 hours ago, Blue Crab said:

Either way you'll need the machine shop. May as well have them boil the block out, do the valve job, resurface the block and head too. 

THIS

 

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You guys are trying to suck me in slowly huh? 

So easy you can do it in the cockpit!

its got sleeves, easy

well no sleeves

just take it to a machine shop you'll be fine:lol:

 

I'm starting to feel better about the state of things right now,  Oil consumption is certainly less that prior to the hard run, Gonna follow Sassafrass' advice and press pause for a while.  

 

 

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1 hour ago, redtim said:

You guys are trying to suck me in slowly huh? 

I'm starting to feel better about the state of things right now,  Oil consumption is certainly less that prior to the hard run, Gonna follow Sassafrass' advice and press pause for a while.  

Yes, good new about the oil consumption. Diagnosticslly it implies the issue is not hard metal wear but more likely extreme crud. As I wrote long ago, my advice would be to schedule a peek both in the crankcase and under the head. No need to even consider a rebuild until more is known. If it were mine I sure would like to know what is going on inside.

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If a hard run lowered the oil consumption then I suspect cylinder glazing was the culprit.

Keep running it hard and see if the consumption continues to drop. You could try a couple of treatments with Sea Foam - it has the rep of being a quick & dirty glaze breaker.

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2 hours ago, SloopJonB said:

If a hard run lowered the oil consumption then I suspect cylinder glazing was the culprit.

Keep running it hard and see if the consumption continues to drop. You could try a couple of treatments with Sea Foam - it has the rep of being a quick & dirty glaze breaker.

Good mosquito fogger too.

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1GM’s are bad for corroding out the mixing elbow, with raw water then getting into the exhaust port, one engine needed a new head as the port had corroded so much that it had no structure between the port and the under rocker cover area. High sulphur diesel didn’t help the situation. Inspect the mixing elbow well especially where the raw water is injected. Previous owners may have installed an after market elbow, note stainless steel is not better in this application.

If the oil consumption has settled down after hard runs you are in luck, change the oil and use a simple mono grade oil at SAE 30 or 40 depending on your temps may help. They don’t need more modern oils.

A simple cylinder hone and re ring should be what you need and could be done in a weekend. Running low on oil would mean a close inspection of the big end bearings, if worn then the mains, gudgeon bearings and oil pump would be impacted to. This is a bigger job, with full strip and hot tank as suggested. This would be a job to big for an inexperienced person without guidance and tooling.

Cylinder head tidy up and injector overhaul would be the other recommendations as others have said. 

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As has been said multiple times, change the oil now!  If it was a crud/glaze issue, and you've cleaned some of that off, it's now in the old oil.  A quick oil change is cheap, good insurance your not now running that crud thru the rest of the motor to cause wear

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Yep, changed the oil after the hard run, it was pretty dark. After a few trips the oil in there now has remained pretty light. Light enough to make it hard to tell what the level is.  
im running 15w40 now, had some sae 30 in for a while, but that didn’t make much of a difference. I figure even if the engine doesn’t need it, modern oil can’t be more harmful than the old stuff, and should have some benefits, so why not use it.

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You can use straight weight oil if you aren't going to see colder temps.  Never want to go that way on newer engines the tolerances in the bearings are too right.  The 15-40 synthetic is a good way to go, probably the best oil you will get as long as it's readily available.  Seeing bit clean up on the dipstick is a great sign!

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Clean oil would seemingly indicate that blow-by is not the source of the consumption so... ???

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Oil has many functions and cleaning is one of them especially in a diesel. If it is not getting dirty then it is the wrong oil. These engines don't want to "good" an oil, lived through the 80's with many Japanese engines needing to be rerung under warranty due to bore glazing and Castrol GTX a contributor. Just to slippery gor the technology.  Plain oil, run engine hard and hot ( within limits) and change oil regularly are my recommendations. Your engine though do what you see as best.

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11 hours ago, SloopJonB said:

Clean oil would seemingly indicate that blow-by is not the source of the consumption so... ???

This bothered me the first time I read it upthread. The non-siphonable unsuckoutable remainder usually turns the new oil black immediately. Maybe I've been doing it wrong? 

9 hours ago, Crazy Horse said:

If it is not getting dirty then it is the wrong oil.

Everyone I know runs 30wt Rotella. I think I might be inclined to run at max RPM a couple more  5-10 minute sessions, changing oil each time and call it good.

 

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On 12/24/2020 at 5:07 AM, Blue Crab said:

This bothered me the first time I read it upthread. The non-siphonable unsuckoutable remainder usually turns the new oil black immediately. Maybe I've been doing it wrong? 

Everyone I know runs 30wt Rotella. I think I might be inclined to run at max RPM a couple more  5-10 minute sessions, changing oil each time and call it good.

 

I run 15W40 Rotella, we have much wider weather swings here. When I change oil and run for five minutes, the oil is black. I'd be worried if it wasn't.

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7 hours ago, Ishmael said:

I run 15W40 Rotella, we have much wider weather swings here. When I change oil and run for five minutes, the oil is black. I'd be worried if it wasn't.

Yeah. Tim's clean oil has to be the telling point, tho it isn't telling ME anything.

2020 ... it's the new 42.

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As mentioned upthread, a lot depends on the dead volume in the pan relative to the engine capacity. I can get nearly every last drop of old oil out of my truck's Cummins and it takes three full gallons of fresh oil. It takes more than 5 minutes for it to turn black. My boat's 4JH3-HTE Yanmar has about a half quart of dead volume and takes about 4.5 qts of fresh oil. It goes black as soon as the new stuff mixes with the old...

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I've been changing the oil frequently, I assume that has something to do with it.  I'm not sure how clean oil could indicate an issue, or what issue it would speak to.

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If it wouldn't cost me a $10k repower to drop kick my 1GM10 into the nearest junkyard metal shredder it sure would make me happy.  I hate the noisy pounding smoking little bastard.

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