S/N: 5G500465 Engine vibration is pretty excessive. Machine was bought late August of 2022. I sent it back to Cat for them to look at. I don't remember if they put new motor mounts on or just tightened them. But I got the machine back and it still seemed excessive. The service manager at Cat even said "That's just how they are". We ran the machine for another 500 hrs and when it just happened to come back to the shop, I still think it has way too much vibration. When you're sitting inside of the cab (Cant hear it outside) it sounds like a rod knock or something similar to that. I torqued the motor mounts down to 142 foot pounds. They were a little bit loose. I'm sending the machine back to Cat, but i've got a feeling they wont find anything. If anyone knows if this is a common issue with these machines or if there are other simple things I can check (I dont want to dive deep into repairs whiles its still under warranty), please let me know.
All my 3 cylinder stuff does it at idle. Rattle windows, linkages, etc. And a few of my 4 cylinders, too. If the vibration is only at idle, and becomes acceptable at notch 2 and higher, unfortunately, that's the nature of the beast. But...have you been able to compare it with another?
I agree with heymccall; this has also been our experience with multiple small machines. Including a Kubota 040 we bought new…
I 2016 I demoed a 305 for a week. It had 260 hours on the display. The cab vibrated noisily and at two different engine speeds the cab resonated with the engine, quite severely. That and other issues soured me on that unit. On the other hand, the 305 sold me on that size mini Excavator, which was a major question I needed to have answered. I end up buying a Bobcat E35i with 41 hours on it and am happy with it for occasional needs here on the farm.
I'm sorry, I should have explained more in-depth. It will vibrate and have an odd knock noise (in cab) at any notch, but its more random. I will typically sound/run smooth when you switch to the 2nd notch, but not everytime.
I think the biggest problem is the cabs are too quiet on next-gens. As far as the knock is concerned, probably nothing, but check around your engine fan and shroud for witness contact marks, also check around the exhaust pipe, it'll have a venturi style connection where one piece vibrates with the engine and the other bit is fixed to the machine. They are adjustable. If you're still worried about the nock you could start checking oil pressure on a regular basis and look for a trend. Service manual even suggests this. This process is complimented by cutting engine oil filters open and inspecting for debris. Would be a good idea to do this every 250 hours when you send off your oil sample. Min oil pressure low idle 7.1 psi High idle 28.4 - 64 psi Unscrew the oil pressure sensor and screw something in there, 1/4 NPT from memory. 3 cylinder engines and quiet cabs mean engine mounts need to be very, very soft, which is why they squeak a lot, which most people perceive as fan belts slipping. Complaints are more common than actual problems, I'll say that much. Tell them you think it's that bad you're actually thinking about trading it in, then ask if you can jump in a new 305. That'll give you the best indication about whether you have a problem or not, and will confirm whether or not the service manager is BS'ing you.
Cat ended up finding a rubbed harness causing an intermittent misfire and they found that the first time they changed the motor mounts, they installed them incorrectly. All warrantied. Got the machine back and it appears to idle as it should now.
Thanks for reporting back. Warranty is always a good result.