Generator in trouble

I have a 41 CHB with a 3 cylinders Northern Lights Gen. set. It was working perfectly until a week ago the exhaust elbow broke right where the water enters the exhaust. I didn't recognise what had happened because the set is in a sound box. Eventually smoke rose out of the engine room and I shut it off and investigated. The cast iron elbow had broken and I replaced it with a SS one from Northern Lights along with a new air filter and 4 injectors. (Salt water got all over everything) Now it is smoking and I am not sure the smoke is exhaust, it may be unburst fuel from one of the cylinders. And it is Making oil. that is the oil in the crankcase is growing. It isn't water I am sure of that , it is Diesel. It will not take a load and I am at a loss as to what has happened to my beloved gen. set.

Possibilities appear to be: Bent valve or maybe a broken piston or broken ring set on one of the 3 cyl

Any ideas, it is in a very BAD place to work on

Hamp Phillips said:

I have a 41 CHB with a 3 cylinders Northern Lights Gen. set. It was working perfectly until a week ago the exhaust elbow broke right where the water enters the exhaust. I didn't recognise what had happened because the set is in a sound box. Eventually smoke rose out of the engine room and I shut it off and investigated. The cast iron elbow had broken and I replaced it with a SS one from Northern Lights along with a new air filter and 4 injectors. (Salt water got all over everything) Now it is smoking and I am not sure the smoke is exhaust, it may be unburst fuel from one of the cylinders. And it is Making oil. that is the oil in the crankcase is growing. It isn't water I am sure of that , it is Diesel. It will not take a load and I am at a loss as to what has happened to my beloved gen. set.

Possibilities appear to be: Bent valve or maybe a broken piston or broken ring set on one of the 3 cyl

Any ideas, it is in a very BAD place to work on

Click to expand...

HIGHLY recommend that you call Northern Lights first thing tomorrow.

They are VERY responsive and helpful.

Yes, you may have a serious issue but do start with them.

Welcome to the forum. Sorry for your troubles.
Just thinking out loud where.
What was wrong with the injectors? At first thought I am Not sure how a broken exhaust elbow could damage the injectors. It sounds like you are pumping raw fuel into the engine which is making its way to the crankcase. That would cause excessive smoke. But this is after you installed new injectors? Something doesn’t jive here.
Did you get seawater in the cylinders? That could damage a piston? Or ruin an injector I suppose.

I might pull the injectors again. Retrace your steps.

I am sure that others will chime in however please let us know the cure when you find it.

I have one of those and changed the iron elbow to stainless fortunately just before it burned through. With the exhaust elbow breaking right at the water injection point I would be concerned that water entered the closest cylinder if not while running then at shutdown, then either bent a valve with subsequent piston damage and/or bent connecting rod. If you’re suddenly putting a lot of fuel into the oil, it’s likely you have a cylinder that’s not firing. I would think pull the injectors and do a compression test then go from there.

Ken

My exhaust elbow is failing now, cast aluminium.
Be a few weeks until I get somewhere that can repair properly so I have been patching every dozen uses with epoxy glue and chopped up glass fibers.

Exhaust manifold is cast ally as well, steel bolts join the two and they'll break for sure when I try and get them apart.
Might need to remanufacture a complete new unit.

Of course none of that helps the OP

Sorry to say you are down a cylinder. Here is a simple test. Run the gen. Loosen the diesel line to the injector. One at a time. Yes fuel will spray. If the cylinder is combusting the speed will drop. If no change , cylinder is dead.

You are going to need professional help with this. A compression test will tell you if a piston or rings are broken. Then there’s a leak down test. If you have smoke in the engine room something else is still broken. Again a pro generator mechanic will be used to access issues. But it’s going to cost $$$$. Sorry.
The good news is it still runs. It’s not seized or hole in the block.
The tough decision is to fix it or replace completely. That’s why you need an accurate diagnosis.

kchace said:

I have one of those and changed the iron elbow to stainless fortunately just before it burned through. With the exhaust elbow breaking right at the water injection point I would be concerned that water entered the closest cylinder if not while running then at shutdown, then either bent a valve with subsequent piston damage and/or bent connecting rod. If you’re suddenly putting a lot of fuel into the oil, it’s likely you have a cylinder that’s not firing. I would think pull the injectors and do a compression test then go from there.

Ken

Click to expand...

Ken, Did you purchase Stainless elbow from Northern Light or is there someone else making them?

I got it from Northern Lights. They often have deals in the spring and fall where if you spend more than (usually a few hundred) they have a 10 or 15% discount.

Ken

If you have smoke in the ER, the elbow may not be installed right. If you're gaining oil with diesel in the pan, then look at places that have the two in close proximity. That is usually a mechanical lift pump, but can be the seal on the injector pump. It also can be a bad injector tip flooding the cylinder with diesel beyond what the engine can use. Since the engine won't take a load, you're probably running on 2+ cylinders, that looks like a prime direction to look.
Replace the new injectors, one at a time, with an old, known to be working, injector. Start the engine, apply load. Do this one at a time until you find the bad injector, or it doesn't solve the problem. Then you need a mechanic.
I doubt you had water in a cylinder with the broken elbow. The water had an easy path out of the engine. Unless with the new elbow, you cranked and cranked with the seacock open and back flooded a cylinder. And in that case, you would have gotten a hydraulic lock and the engine starter wouldn't turn over the engine.
If you use the method of opening the injector nuts to find the bad cylinder, use lots of rags to catch the diesel and use liquid dish soap to clean the diesel off the engine and rid it of diesel smell. You don't have to open the nuts very far. Just enough to release the pressure. That results in the injector's valve remaining shut and doesn't open, that cylinder doesn't fire. Injectors have a spring loaded valve that prevents combustion debris from getting into the injector.

I agree it's unlikely that the broken elbow resulted in internal engine damage.


I think it's much more likely that something got messed up while replacing the injectors. Someone else asked why you replaced the injectors? It seems kind of random, but maybe there was a reason?


With teh injectors having been replaced, my first suspicion would be that dirt got in and you have an injector stuck open and over fueling. Or one improperly installed and preventing good compression.


If you crack open the fuel line on one injector at a time, perhaps you will find a cylinder where there is no change in how the engine runs, indicating the bad cylinder. Then swap back in one of the old injectors, as Lepke suggests.


Don't just assume a bent valve or broken ring or other catastrophic damage. Something would have to cause that, and there is nothing in what you have described along those lines.

WOW !!! All the help, thanks ! The first person that answered told me to call Northern Lights and that is just what I did. I told him the entire story and his first question was did I replace the foam air cleaner. I said yes then hs asked what condition was the old one in and I told him it was a MESS. He then said that his bet was that I had some of the filter caught in one of the intake valves. I took off the valve cover and right before my eyes was a hunk of foam wedged in one of the intake ports. I took it out, changed the oil and filter again and vala it now performs perfectly. I wish all my problems were so easily solved. Thanks again for all the help, you saved me buying a new generator.

My NL ate an air filter. It knocked the intake valve adjustment slightly off. Adjusted all of them and good to go.