Cat 308E2 mini ex, S/N: FJX04760 Operator that was running it called me saying that the engine over-sped and was running rough after that. I hooked ET to it. and found codes: 636-2: Engine position sensor: erratic 636-8: Engine position sensor: Abnormal frequency 3509-4: Sensor supply voltage 1: Voltage below normal 190-0: Engine speed: High - most severe (3) 1239-1: Engine Fuel Leakage 1: Low - most severe (3) I started with 3509-4, assuming the other codes were resulting from this one. I followed troubleshooting procedures from cat sis. It led me to change the crankshaft position sensor. After I changed the sensor, the engine would start, but run very rough and die shortly after starting. After a couple of times of starting and dying, it would not start and when cranking, it was sounding very rough. I also noticed the engine had a lot of vibration when cranking. All mounts were tight. I then found more problems like, large rub throughs in sections of the engine harness, the turbo seals were shot; resulting with oil in the intake (which I would assume caused the overspeed?). Most concerning, I looked into the muffler section of the DPF and noticed standing liquid in it. I determined it had to be diesel due to its viscosity and color. Once the machine was dragged back to my shop, I took the DPF and Turbo off and noticed a puddle of diesel in the exhaust manifold. I want to assume that the rub throughs in the wire harness are causing the over-fueling? My plans were to change the engine wire harness, get the turbo rebuilt/ replaced, get the DPF cleaned, clean the intake of oil residue and do a valve adjustment while everything is taken apart. Would it be worth it to take the injectors out and evac the cylinders, incase there are large amounts of fuel in them? Or take off the oil pan to see if any cylinders became hydro locked and bent any rods? Sorry for the long read. Any feed back is appreciated. Thank you
Your engine has had one or more Level 3 over speed events. That in itself would indicate the need for a complete tear down. Start with the valve gear and work downwards via the camshaft to the crank, rods, & pistons. My 2c.
Depending on the bobweight , you might just have longer rods and shorter valves. I'm 100% behind Nige on this. She needs to either come apart ir get swapped while you still have a salvageable core.
and Indicate to me an injector is stuck open. I think it'll be a miracle if you don't have a bent rod or cracked piston. Just my 2c
I think if anything the rubbed wire(s) would explain the other codes you have. You'll probably know which injector it is when you pull them... one (or some) of the nozzles will be wetter than others. When you pull the head you'll definitely know. Consider replacing all the injectors during rebuild... otherwise you risk destroying the next engine.
For curious minds, I took off the head and found #2 cylinder had extensive vertical scoring. I found that the piston skirt was slapping against the cylinder walls. I’m planning on putting a brand new engine in soon. Thank you everyone for your help.
Your feedback is worth it's weight in gold, wish more people did it. Don't hesitate to ask questions if you need any help installing the new engine.
I'm about to put a new engine in the machine. The new motor came with a new ECM. Do I need to use the new ECM? Or can I just use the old one? It's also a Kubota made, Cat branded engine, with a Kubota ECM. Do I need to have Cat come out and do something with the new or old ECM with the new engine? Or, being a Kubota ECM, can I do what's required with my Cat ET? I don't know much relating to ECM's.
Was the engine purchased through the Cat dealer and is it specifically configured for your 308 excavator application.? If the answer is no you may be in for some head-scratching.
It was bought through our local cat dealer. I don’t know if it was specifically configured for my machine. I just know it was purchased from the arrangement number for the machine.
I believe the ECM should come programmed properly to the engine if it came on there, you will need to go in and put the product ID in with ET to marry it to the other ECMs on the machine. Other than that you shouldn’t need to do anything. If it were a blank ECM you would have to use what they call, “Cat ERT” or “engine reprogramming tool” which is a vary finicky program in my experience with it.
In that case, all things being equal, it ought to be plug & play. As @ahart pointed put it might require the machine Serial Number to be put in the engine ECM Configuration screen to enable communication with the other ECMs on the machine.
I'll give that a shot. My next question, is there any specific break-in procedure for these motors?
The maintenance schedule for your machine doesn’t call for the first initial oil and filter change until 500 hrs with an oil sample done at 250 hrs. Personally, I would sample at 100 hrs, 250 hrs, then as long as they come back good, change at 250 then go to your regular maintenance schedule. Will give peace of mind that all is well with the new engine.
As regards running in it should have been tested at the factory which theoretically is all the running in it needs. Just make sure it’s well warmed up then for the first few hours make sure you don’t allow it to lug down too far. I agree with @ahart but I’d go further and change the oil & filter after 100 hours in addition to pulling a sample of the old oil. What’s the oil & filter worth compared to what you paid for the new engine.?
I agree, i've never seen the cause of a major engine failure as "engine oil was too clean"
Is there any procedure for running it hard/underload or light for a certain period after initial start? I've heard for larger motors, you're supposed to have it under heavy load for the first 100 hours and after initial startup, you shouldn't let it idle for over 20 minutes to prevent cylinder glazing. I just don't wanna ruin a nice new engine.
Basically what I said above. Don't let it lug down too far when operating and make sure it's well warmed up before putting it under load first thing in the morning. Not letting it idle for more than a few minutes during operation is a good recommendation for any engine.
We have the same model excavator, they started it cold one morning and engine got ahold of some oil and it lit that oil on fire and burned it and it kept doing that until the engine was destroyed I was not there but they tried to stop the runaway diesel with rags everybody and everything was covered in burnt oil not to mention black smoke high enough that they could see it at the cat dealer. now our machine is abused by almost everyone who gets in it and caterpillar replaced the engine under warranty that time, but the machine has been plagued with problems ever since it’s a very handy machine just be cautious and take care of it.
Just so I have a complete understanding relating to the ECM. I should put on the new ECM that came with my new engine? And to mate the new ECM to the machine, I need to enter the product ID into the new ECM? is that the same as putting the machine S/N in the ECM?
That is correct
In the ET Configuration screen of the new engine ECM right at the top there should be two blank fields. One is for the "Product ID" which is the machine Serial number, and one is for the "Equipment ID" which is for the internal fleet number of the machine if your company uses a fleet numbering system. The 2nd field can be left blank if you don't use fleet numbering and will appear as "Not Programmed" in the Config screen. Examples of both options below.
Here is the what comes up for me with the new ECM. The engine ECM is not showing up. Am I missing something?
Yea that’s definitely an issue, need to get into the schematic and check for battery power, keyswitch power and ground on the chassis to engine ECM connector.
The arrangement number needs to be the same on both engines for it to be completely plug and play. We need the the serial numbers and arrangement numbers for both the old and new engines so we can give you the right information. FYI, based on your machine serial number (FJX04760) your old engine should be s/n 8FS2362 arr 392-4110 Only thing I would do to a new engine is disable the auto idle feature on the screen menu for the first few hundred hours of operation.
I did not have the mass air flow sensor connected. Once I plugged that in, ET showed everything.