1, the engine cylinder (combustion chamber) is flooded and the engine connecting rod is bent or broken. When the vehicle runs on a road with water on the road surface, the engine will suck water into the cylinder. The water that initially enters the cylinder quickly forms hydrated gas under the action of the high temperature of the cylinder, so that the cylinder cannot form combustible gas mixture.

With the increase of water inflow, water will accumulate at the top of the piston, which will reduce the effective volume of the afterburner, increase the compression resistance and increase the pressure transmitted by the piston to the connecting rod.

2. The abnormal fuel injection system of the engine causes the connecting rod to bend or break. This situation is generally caused by the continuous injection of fuel by the injector of a certain cylinder of the engine. Often before, there will be difficulties in starting, idling jitter, black smoke from the exhaust pipe, power drop and so on.

After disassembly and inspection, it can be judged by observing the combustion situation of each cylinder. For the cylinder with more fuel injection, because the combustible mixture is thicker than other cylinders, the cylinder and cylinder head will be darker than other cylinders. At the same time, the fuel injector and its fuel injection control circuit can be further inspected.

3. The engine connecting rod is bent or broken due to the locking between the connecting rod and the crankshaft. This situation is generally caused by poor lubrication of the engine, which can be judged by checking the wear of internal parts of the engine.

4. The connecting rod itself is bent or broken due to problems. This situation can generally be determined by chemical composition analysis, hardness test, metallographic examination and SEM fracture analysis of connecting rod materials.

Extended data:

Methods of checking the causes of engine connecting rod bending;

1, whether the air filter is wet and whether dirt is attached; Whether there are water marks on the air cleaner housing and intake pipe wall.

2. Check the engine oil to determine whether there is water in the engine cylinder. After the engine enters the water, the oil around the engine cylinder head and intake and exhaust valve seats will appear milky white, which is the result of mixing water and oil.

3. Check the piston and connecting rod to confirm whether the engine is flooded. When the engine connecting rod is broken due to water in the engine cylinder, the piston top of the broken connecting rod will be bright (compared with the piston top of the unbroken connecting rod).