Vibrating C15 Caterpillar Engine

A lot of times this can be as simple as an injector timing problem.

Maybe even a loose motor mount

Could also be a harmonic balancer problem

The alternatives could be much worse so start with these

I would suggest looking at the fuel injectors firstly (the engine is very new & if the oil is okay should not be suffering mechanical problems) after the injectors check tappet clearances (if excessive engine will sound like Spanish castantents - then check flywheel bolts (connection between engine & alternator)

99% it's fuel & injector related (dirty fuel can affect injectors instantly)

Totally agree with injector potential BUT you might want to check your oil as well.

I assume that you are using an outdoor tank, if only for oil before the engine. You are in an area with potential for high humidity, especially at night, and you may have gotten water condensing and mixing with the oil- causing a firing problem very much like a dirty injector but happening in any and all cylinders randomly.

Use a clear plastic hose (about 25 MM diameter) and insert it into the tank at least 2 meters. Then, close off the "dry" end and extract to see what your oil "mix" looks like. If it is clear- just oil- then put the tube back in straight down to the bottom of the tank and extract some oil from the bottom- if you are having any condensate, it will definitely show up then and is likely getting into the oil assuming that you are drawing oil from the bottom of the tank.

If you see water on the tank bottom, you can install a pipe-in-pipe to get your intake at least 150 MM above the bottom of the tank. Then, periodically, blow down your tank to remove any moisture that might build up. Drain it into a 2 liter glass beaker with a relatively narrow opening and then cap it with a stopper with two thin tubes- one almost to the bottom of the beaker and the other just into the stopper. When you turn the beaker upside down, you can drain off the water with the tube the is in the stopper (air will go into the beaker through the other tube) and leave the oil in the beaker. Then, turn it back over, remove the stopper and return the oil to the tank.

Wet stacking?

I have seen this on everything John Deere, Kubota, Cat, Izuzu, Cummins, Mercedes Industrial, Komatzu, I would have to say 80% of the time it is injection timing.

Have only encountered it once when clogged injectors were the cause and that was on a 5 cyl which is hard to balance anyway.