Engine Noise? Or am I hearing things?

[conquistador]

Ok, another dumbly entertaining newbie question. I'm running my Kubota L2050 with a 5ft Caroni finish mower. Rpm's set around 2100. Engine purrs like a kitten on the flat parts of the yard, but when it gets under stress, I hear what sounds like a little valve chatter. It doesn't spit any smoke or act strangely, I just hear something like the valves chattering coming from the engine. So, is this something I need to be concerened about or am I just a new, over-protective parent??

 

[eserv]

I think you are hearing the classic combustion sound of a diesel engine under load. Have you listened to any other diesel's under similar condition's? I don't think I'd be concerned about it.
Ed

 

[conquistador]

I kinda figured that was what it was but I figured I'd ask here to be sure. Just another over protective parent concerned for his new child I guess. Then again, I'd rather look dumb than have something go wrong and not ask a question!! (That must be the teacher coming out in me.)

 

[conquistador]

Yep, running at 540rpm. I was cutting the in-laws grass which had gotten high in some places, plus factoring in that I was mowing on hills and I gave my little Kubota a decent workout. I figured what I was hearing was probably normal, but the little voice in my head told me to go ahead and ask anyway. I'd rather ask an obvious question than be looking at a dead tractor with a dumb look on my face.

 

[aheberly]

This post if 4 years old, but I actually had the same question and it sounds like a little knock is fairly normal.

ALH

 

[Bulldog]

You put a diesel under load and it does make sort of a knock type sound. Some are worse than others but more than likely what you are hearing is normal engine sounds.

Now if what you are hearing is a new noise that just started up out of the blue might be worth getting a second opinion.

 

[Stumpy]

The rate of combustion in a diesel is much quicker than a spark ignition motor. It's one reason why they're build so much heavier. The result is that when the injector fires the piston gets violently slapped against the piston wall and connecting rod and that is where the characteristic diesel clatter comes from. It's actually violent enough I remember reading somewhere some engines can get pits in the liners from the coolant cavitating! Kubotas, to my knowledge are all indirect injection motors so combustion is a little slower, try a direct injected motor if you want some piston slap!

I agree with Bulldog, it's more than likely normal but if it's really bugging you get someone to listen to it.