Hello, Cat 325 BL (2JR1-up) just started blowing heavy smoke and has no power. We lifted off the valve cover and found injector #6 with a cracked/ broken spring. This is a 3116 engine. How could that spring on an injector break like that- is it just age and wear and tear? There appeared to be diesel (unburnt) coming out of the exhaust and out of the turbo. So it appeared the broken #6 injector would have caused one cylinder to flood with diesel. The cylinder cannot compress a liquid so it expels this unburnt diesel out the exhaust valve and into the exhaust and past the turbo. We have now replaced the #6 injector but the engine is still without power and smoking but now is expelling engine oil out the turbo. When we removed the exhaust manifold it appeared dry. We can spin the turbo so the bearings on it are not seized. Now one of us thinks it could be the turbo - he wants to order a new turbo as he thinks the diesel fuel blowing out of it would have damaged the oil seal and he thinks it is turbo oil blowing out. He thinks the turbo is not spinning fast enough and delivering the oxygen to burn the fuel and that is why engine is still smoking and underpowered. Another of us thinks it could be a cylinder piston ring that is broken and he thinks the oil blowing out the exhaust is coming from the engine. He thinks we should remove the turbo, attached the turbo oil hose in a loop to feed back into the engine, and test it again to see if the oil is actually originating from the engine and not the turbo hose. We do not want to order a new turbo only to find out there is still something wrong and we did not need it in the first place. Do you think the diesel fuel running out the turbo could have damaged the turbo oil seals to cause turbo to leak oil in exhaust and turbo not to spin effectively to cause engine to be weak and still smoke?
can you do a leak down test on the #6 cylinder? that will tell you if you broke a ring
(E) All of the above?
If you didn't get all of the fuel cleaned out of #6 cyl from changing the injector it will blow it out the exhaust for a long time. Have you checked all of the racks are moving? Have you been losing any antifreeze? Later Bob
Youtube video link: https://www.youtube.com/watch?feature=player_detailpage&v=-FOFur_ZW1g of engine running and smoking from last night, after we already put on the new #6 injector. We ran it briefly with the valve cover off. Turbo had some engine oil coming out of exhaust side and engine has little/ no power
No, excavator ran fine until she started smoking and lost power. She did not lose antifreeze.
The reason I ask is many years ago(5) I had to re replace the #5 injector due to breaking another spring. When I had it out noticed something funny and pressurized the rad. Coolant poured out around the top of the copper sleeve. Changed the sleeve and put in another exchange nozzle complete with top set. Customer didn't want to spend to go the distance, talked about selling it. I suspect the second broken spring was due to antifreeze mixing into the fuel. Take some of the fuel from the tank, heat up a plate with torch and pour fuel onto hot spot, look for bubbles coming up to surface. Later Bob
That broken spring might not have been your problem, have you set the injectors? Just cap off oil feed of turbo to run without turbo, does all the fuel linkeges move freely, the same?kind of sounds like you have a injector over fueling, sounds like fuel knock.
How hard would it be to pull the exhause manifold to see if oil is coming from one of the cylinders. Plug off the oil line to turbo and start it to see if there is a problem in one cylinder?
Sounds like its over fueling on one or more injectors. Check to see if all the injector control racks are moving freely. You may have another bad injector . It would be a good idea to test it with the turbo off and oil line capped
i wouldnt run it with turbo still spinning and feed line capped.You will ruin turbo for sure. just saying
They want to run it with manifold off, that's the reason to cap oil line.
From looking at your video it looks like you have a jammed rack in one injector. The jammed injector will not zero and will over fuel at idle and it will also stop the rest of the injectors from getting past it's stuck point and getting to full fuel. That will cause low power and excess smoke, fuel left in cyl and piston crater will run out of exh. I would recommend taking them all out, pressure testing the cooling system to make sure sleeves aren't leaking then ream the sleeve seats. Install a set of exch injectors following the instructions to the letter. It's important to get them seated right or compression will get into the fuel and foam it up resulting in more low power. Later Bob
Took off the turbo and capped off the turbo oil port. Turned over the engine and some diesel fuel was coming out of the exhaust. Took off the exhaust manifold and #6 and 4 (maybe some in #5 also) are wet with diesel fuel. #3, 2, and 1 are dry. Photos attached. Rocked the rack arm and it moved free and fine on all injectors. The new #4 and #6 injectors we replaced were set and adjusted with shim and torqued to specs. However they are not seated completely as evident from the fuel leaking from #6, 5, and 4. We think we need to ream the sleeves in #6, 5, and 4 to get them to set fully and seal. Problem is we do not have the special tooling to do that. We think we have to call the Caterpillar dealer and get them to come out and finish our work.
Update Cat dealer mechanic came today. He pumped out the diesel from # 6 and 4 injector sleeves. Dried out the sleeves, shown a light and #6 had just a spot of coolant leaking in. He was not sure if the sleeves were reamed before and if there was enough metal left to ream them. He said we need to change the injector sleeve on #6 and suggested we might as well change all 6 injector sleeves at the same time. Bought the 6 sleeves- photo attached - they are pretty thin. He used a special tool to remove the old sleeve but #6 gave him a hard time. He could not get it out and thinks the tooling is worn. His boss is ordering a new tool set which will hopefully get the old sleeves out better. We do not want to take the head off if we can avoid it.
You got her Pontiac. Later Bob