79 BJ40 B-engine Excessive Smoke and Oil from Crankcase Vent Tube (1 Viewer)

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I have a question about excessive smoke and oil from the crankcase Vent Tube. I sent my 79 BJ40 TLC to a local diesel shop to fix a coolant and fuel leak, after it had sit for several months (deployed for 8 months). Coolant issue was freeze plug and fuel leak was worn fuel lines. The mechanic had to remove head to replace freeze plug and when he did he discovered that one of the glow plug ends had broken off into the cylinder, which caused a minor "scratch" to the wall of the cylinder. Mechanic said it shouldn't be an issue and I said no problem, especially after he told me how much it would cost to have it repaired. Today, I picked it up and right away the mechanic told me there was excessive smoke and oil spitting out of the crankcase vent tube. The thing is, it never did that in the past except only a little at startup. Did the mechanic put something back together wrong? Why would it all of a sudden start doing that? Was it because it sat so long and may go away after I drive it around for awhile? Thanks in advance.
 
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Glow plug tip shouldn't damage the bore, unless it imbedded itself between the piston and cylinder, which is highly unlikely.
Sounds like you have broken rings. Not a cheap repair, I'm afraid.
 
Glow plug tip shouldn't damage the bore, unless it imbedded itself between the piston and cylinder, which is highly unlikely.
Sounds like you have broken rings. Not a cheap repair, I'm afraid.
Thanks fitzmooney. Since it was sitting for several months, do you think that caused the broken ring(s)? The reason I'm asking is it did not spew oil or excessively smoke from the vent tube until after I received it back from the shop. I never started it after it was sitting for several month, I sent it straight to the shop after seeing the coolant and fuel leak.
 
You could just have a frozen ring. I left glow plugs out if a 3b for a year and moisture got into it and rusted/froze my rings. Couldn't start it or get compression till I filled the cylinders with metal rescue and drained it out. Metal rescue is not acidic and is aluminum friendly and super cheap and non toxic and smells like potpourri. Try the simple things first before you say it's broken. I've also had great success with ac delco upper cylinder engine cleaner. It disolves Carbon which can also sieze rings. It is very toxic and smells like brain damage.
 
Thanks gerg. I will put some Marvel Mystery Oil (2oz) into each of the cylinders and let soak for a couple days and add about a 1/2 quart into the crankcase, which was about how much oil I lost through the vent tube. For good measure, I'll also put about 4ozs of Cetane Booster into the fuel tank. I'll post the results. Thanks again!
 
MMO is just an oil remember. It wount affect rust much. I suspect even if you ran it for a while the blowby might decrease. I'd just keep a keen eye on the oil level. I would recommend against putting it in the crankcase. Releasing large amounts of engine debris into the system can have catastrophic results. Namely from completely plugged oil pick ups. If you do want to go that route I'd recommend auto- rx. It works slowly and does the same thing. If you do that I'd also recommend a bypass filter to catch the released crap. Your regular filter only catches the huge chunks. Doing these processes should be slow and the oil should be very well filtered. Strangely I'm in the middle of that process right now and my blowby is already reduced by 1/2. Engine starts better and has more power. No smoke under load, although I'm boosting more air than I need, but I removed my fuel screw completely to get the most I could out of the pump. Very happy with the results.
 
Great info gerg. I will take heed to all your recommendation. Take care.
 
Well, after the Magic Marvel Oil(1 tbsp per cylinder) sat in the cylinders for a few days, it still spews oil and smoke from the crankcase vent tube.... I let it run for 15 minutes. A couple questions;
1. Will it take a few more cycles for it to loosen the rings?
2. I discovered after removing the glow plugs to put in the MMO, that the shop had reinstalled new 24v plugs verses 12v, which questions the shops understanding of this engine :-(. When I received my invoice I noticed they had 3B and not B for engine type, would having replaced the head gasket with a 3B cause the issue?
Thanks again for the assistance.
 
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...I sent my 79 BJ40 TLC to a local diesel shop to fix a coolant and fuel leak, after it had sit for several months (deployed for 8 months). Coolant issue was freeze plug and fuel leak was worn fuel lines. The mechanic had to remove head to replace freeze plug and when he did he discovered that one of the glow plug ends had broken off into the cylinder, which caused a minor "scratch" to the wall of the cylinder. Mechanic said it shouldn't be an issue and I said no problem, especially after he told me how much it would cost to have it repaired. Today, I picked it up and right away the mechanic told me there was excessive smoke and oil spitting out of the crankcase vent tube. The thing is, it never did that in the past except only a little at startup. Did the mechanic put something back together wrong? Why would it all of a sudden start doing that? Was it because it sat so long and may go away after I drive it around for awhile? Thanks in advance.

Thanks fitzmooney. Since it was sitting for several months, do you think that caused the broken ring(s)? The reason I'm asking is it did not spew oil or excessively smoke from the vent tube until after I received it back from the shop. I never started it after it was sitting for several month, I sent it straight to the shop after seeing the coolant and fuel leak.

....I discovered after removing the glow plugs to put in the MMO, that the shop had reinstalled new 24v plugs verses 12v, which questions the shops understanding of this engine :-(. When I received my invoice I noticed they had 3B and not B for engine type, would having replaced the head gasket with a 3B cause the issue?
Thanks again for the assistance.

Hi there Ifields57

I've been resisting commenting until now, but even now I think my comments will be of little or no help to you. (Sorry)

I can't see how an incorrect head gasket can cause excessive blowby because for exhaust gases to enter the crankcase they must pass between the pistons and cylinder walls and that gasket has no effect there.

Fitting the incorrect glowplugs does question your mechanic's competence ... but not to the point of writing him off as being incompetent IMO.

But your experience here is exactly why I prefer doing all work myself... (You're left with suspicions that the person who worked on your engine has done something seriously wrong... )

I notice that you say "You sent your BJ40 ton the mechanic" rather than "You took it".
I'm guessing that means that someone else drove it there or some form of vehicle-transporter was used (perhaps while you were still deployed). If so, that unfortunately complicates matters further because you wouldn't then have first-hand experience of the "true running condition" of your engine on arrival at the mechanic's premises.

Sitting for several months doesn't seem to me to be sufficient to cause rings to "seize up" (and thus to suggest a cure could be achieved by "freeing them".)

Which freeze plug did the mechanic say he had to remove the head in order to reach? Right now I can't think of one that would require that step. (I know of one where "complete engine-removal" would be required and another one or two where "injector pump removal" would be required, etc etc.)

Perhaps the answer to this question will enable us determine the competence or otherwise of your mechanic?


:beer:
 
My guess the minor scratch is a major score that begs the questing who was driving the truck when it supposedly dropped the injector tip. Maybe the mechanic isn't being honest was he using the truck when you where deployed or did he lend it out. To drop off a good running engine and then be told he found a injector tip inside the engine sound suspect to me.
 
From experience,

if you're BJ40 sat in a field, back lot, compound etc., for 8-9 months unattended while you were on a Crusade/deployment,
check to see that your muffler is able to 'vent', as vermin like to make there homes in the muffler and reduce flow.
 
How many klms has it done? When old engines sit around for long periods, the sludge build up around the rings can dry out and shrink resulting in blow by. Your next problem could be that the blow by wont allow the sludge to build up again. It built up when the engine had more metal and less clearance..
If someone with no patience drives these old N/A diesels , they can force engine gases past the rings.

I would try a thicker oil and give it a 1000miles or so but I see a rebuild coming.
 

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