1GM10 burning oil. Problem? Not a problem?

G

Guest

Guest
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.

 

Zonker

Super Anarchist
9,285
5,215
Canada
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.

 

2airishuman

The Loyal Opposition
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

 
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

 

andykane

Member
438
202
Victoria, BC
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.

 

Blue Crab

benthivore
15,407
2,400
Outer Banks
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.

 

SloopJonB

Super Anarchist
67,109
11,547
Great Wet North
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.

 

IStream

Super Anarchist
10,786
2,972
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.

 
Last edited by a moderator:

Zonker

Super Anarchist
9,285
5,215
Canada
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.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.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.

 
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!!

 
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.

 
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.

 

Blue Crab

benthivore
15,407
2,400
Outer Banks
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. 

 
Top