1GM10 burning oil. Problem? Not a problem?

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.  

 

El Borracho

Sam’s friend
6,345
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Pacific Rim
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.

 

SloopJonB

Super Anarchist
65,949
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Great Wet North
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.

 

Ishmael

Granfallooner
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Fuctifino
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.

 

Crazy Horse

Member
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33
Queensland
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. 

 

Crash

Super Anarchist
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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

 
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.

 
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!

 

Crazy Horse

Member
227
33
Queensland
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.

 

Blue Crab

benthivore
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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? 

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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Ishmael

Granfallooner
49,585
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Fuctifino
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.

 

Blue Crab

benthivore
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Outer Banks
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.

 

IStream

Super Anarchist
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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...

 

Metrognome

New member
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.

 
Chapter 2 of this little saga.

The 1gm10 started puking oil into the bilge, and for the life of me I could not find the source.  So bought a suspect used 1gm10 and swapped them.  Huge pain in the ass but only a week without the use of the boat, so kind of a win.  

The problem now is the suspect 1gm10 is smoking like crazy and won't come up to full RPM under load.   I've replaced the fuel injector hoping that might help, but no dice.  

The smoke is pretty much white or grey, though lots of soot comes out when pushing past about 2500 rpm, which is about the maximum I can get.  in neutral, the engine will spin up to full RPM no problem. though still tons of white smoke.   

There is some pressure in the crank case, i don't have any clue what is normal there, if i take the oil cap off, i get a lot of air coming out, but i can easily stop it with very light pressure using my palm.   I was hoping to get lucky and not have to rebuild the old one, still hoping for a fix for the new engine that doesn't involve tearing the whole thing apart.

 

Blue Crab

benthivore
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Outer Banks
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.
I missed this. The point was when everyone else puts fresh oil in ... in seconds it's all black. Upthread you mentioned fresh oil stayed pretty clear. It shouldn't.  Even if you could siphon 99% of the old oil out, the 1% clinging to the pan walls would turn the fresh black.

It's a clue. That's all I got.  

 

Zonker

Super Anarchist
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Is the new one salt water cooled? White smoke is usually steam (think head gasket)

If fresh water cooled, is it losing coolant?

Not being able to get up to speed means probably not enough compression (again, a leaky head gasket) since you've cleaned the injector.

Soot is unburned fuel. So if you're not compressing enough then your combustion is insufficient.

 
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