(1) Is the air filter damp and attached with soil; are there water marks on the air filter housing and the intake pipe wall.

(2) Check the Cummins Engine oil to determine whether there is water in the Bare Engine cylinder. After the Bare Engine enters water, the oil around the Bare Engine cylinder head and exhaust valve seat is milky white, which is the result of the mixture of water and oil.

(3) You can confirm whether the Cummins Engine has water ingress by checking the piston and connecting rod. The Bare Engine breakage caused by water ingress in the Bare Engine cylinder, the top of the broken connecting rod piston will be very bright (compared with the top of the unbroken connecting rod).

The broken connecting rod is bent. In addition, we can also judge by observing the high problem (top dead center) of the piston ring movement on each cylinder sleeve.

We can find that the top dead center of the cylinder corresponding to the broken connecting rod is significantly lower than that of other cylinders, which can also help us judge that the connecting rod is broken after bending and running for a period of time.