2020 diesel sounds funny

[DogT]

Was out mowing with the IH451 yesterday. It started sounding funny, like one of the cylinders maybe wasn't firing, sort of a thumping sound, so I put it in the barn. I didn't notice any lack of power that I could tell. Got it out again today and finished mowing, maybe 3 hours worth and it still sounds funny. It's just kind of a vague thumping, but it sounds different somehow. At the age of this thing I'm wondering if it's worth maybe throwing a set of injectors into it for $125 from amazon. Many years ago, maybe 10-15, I had it at the JD dealer and they did some work on the injectors. Not like I put hours on this thing, use it for mowing with the 451, maybe 50 hours a year, grading the road which may take up another 5-10 and whatever snow I need to plow in the winter, not much there. I thought throwing injectors into it may be cheaper than taking it to someone for a checkup and maybe nothing lost. I could also change the diesel filter which hasn't been done in a couple years. Injectors don't look like a large job. I should probably get new gaskets for them though.

Ideas? Thanks,
Dave

 

[beenthere]

"throwing" parts at it doesn't sound like a great idea... to me. Good luck.. We can hope for the best.

 

[DogT]

Yeah, I know, but would it hurt? It might make me feel better. The trip to the JD dealer was over 10 times what the injectors cost and all they did was clean a few injectors and replace the fuel pump which was the real issue that I missed.

 

[Tx Jim]

I highly recommend checking frt hyd pump drive for wear. $12 worth of bushings(4ea- R45822) could possibly be causing the noise. How long since cyl head valve clearances &/or inj pump timing were checked?

 

[DogT]

Thanks, I can look into the pump first. I was thinking about that. I've never checked the valve clearances or timing, I do have the plastic timing window gizmo in my box. Better get it done before the weather gets bad.

ed:Oh, wait, you're talking about the hydraulic pump, not the injector pump. I replaced that pump maybe 15 years ago, but the system is full of crap from the brakes that were not replaced in time before I had it. It sounds more like a motor issue than hydraulic though. I keep magnets in the hyd filter and do change it regularly.

 

[Zebrafive]

Maybe a "laser temp gun" can be used to check cylinder exhaust temp on the exhaust manifold?
You would have to do it from a cold start, before heat from the other cylinders heated all the exhaust ports up.
A "colder" exhaust port would indicate a non firing cylinder?

 

[super55]

If your itching for a project on the injectors it would your time to go buy a pressure tester and bench test them. They are pretty reasonably priced and will give you an idea of the pressure they are releasing and spray pattern.

Just out of curiosity does your oil pressure drop at all while operating or while the engine is warm or does it become more prominent when engine is cold or warm?? Does it sound like it might be coming from the top of the engine or the bottom? If a cylinder wasn't firing you would notice a power loss. I might be inclined to think it could possibly be a spun bearing. Might be worthwhile to do an oil change and cut open the used oil filter to see if there are any shavings or a metallic shine in the oil.

 

[ruffdog]

Can you see each cylinder exhaust as it exits the head and becomes the exhaust manifold? Before you start it next time, get a plastic spray bottle something like shower or glass cleaner comes in and fill it with water. Then, start the tractor and spritz the exhaust for each cylinder. You will start seeing that the good cylinders will steam off the water quickly while the lame cylinders don't. Now you know if you have cold cylinders and which ones they are.

 

[beenthere]

ruffdog
Clever way to test for cold cylinder. thanks for that tip

 

[DogT]

All good ideas to play with. Metallic shine in the oil, yes in the hyd oil since I've had it. The sound is more of an exhaust sound that I can tell, but it's pretty subtle. And it just seems that the engine is running a bit unbalanced, and yes, if one cylinder wasn't working, I would think I would notice it. But I didn't notice the difference when I had it into the dealer before, but I did when it came back. Sometimes these things creep up on you without your noticing. But if one cylinder quit right away I think I'd notice it especially when mowing. Although the 451 is not much of a load on it.