2023 L3560, 100 hours, suddenly rapping and hissing noise from engine

JerkyChew · 2025-09-22T01:15:54-0400

So I fired up my tractor today, it's the L3560 with the cab. As I was driving I thought I heard a rapping noise coming from the engine. I opened the cab door and realized that in addition to the rapping there was a crazy hissing noise coming from the engine as well. I shut it off and popped the hood. I didn't see anything out of the ordinary so I fired it up again - Same problem, so I shut it off again in case there's a hydraulic leak or something. It has been sitting in my yard unused for about 2 weeks, but otherwise nothing out of the ordinary has happened to it, and it worked fine the last time I used it. The tractor was just serviced by the dealer at 80 hours and I have the extended warranty so I'll be calling them tomorrow, I just was curious if anybody had any immediate ideas. I know a bit about gas engines but not much about diesels so I have no clue what else to check, if anything.

I took a quick video of the noise. It's a little tough to hear the hissing, at least to my ears. YouTube made it a short for some reason:

RjCorazza · 2025-09-22T07:51:53-0400

Sure sounds like exhaust, rather than a mechanical noise to me.
Hopefully it will get straightened out with the dealer quickly.

Hay Dude · 2025-09-22T08:06:41-0400

I can’t tell from the video, but an exhaust manifold leak would be my guess based on 8 seconds of video

Paystar · 2025-09-22T09:00:28-0400

I can't tell in video, but is it just doing a regen? I know my diesel trucks have a distinct and hissing sound when they regen.

RjCorazza · 2025-09-22T09:43:25-0400

Paystar said:
I can't tell in video, but is it just doing a regen? I know my diesel trucks have a distinct and hissing sound when they regen.

That's an interesting thought, but my L4060 doesn't sound like that during a Regen. Could still be related to the dpf though.

Paystar · 2025-09-22T10:46:31-0400

RjCorazza said:
That's an interesting thought, but my L4060 doesn't sound like that during a Regen. Could still be related to the dpf though.

OK, was just a thought because even my Cat wheel loader at work makes a loud hissing while it's doing a regen if you let it drop to an idle.
I wasn't sure if the small Kubota's changed sound also?

JerkyChew · 2025-09-22T13:45:51-0400

Thanks for all the ideas - I forgot to mention that oil appears to be dripping out of the exhaust as well. I'd video it but I don't want to start the thing and risk damaging it further. I've reached out to my dealer and am waiting to hear back. A loose manifold would be great, just because in theory it's not a sign of a larger engine issue. I don't think it's doing a regen because I didn't notice any lights or statuses on the dash, and I just did a regen not even five engine hours ago.