(1) valve erosion. The main exhaust valve, due to poor material or exhaust temperature is too high, causing the valve cone ablation, or because of the valve seat deformation caused by cone ablation. In addition, the valve clearance is too small, or the valve spring is too soft, resulting in leakage and ablation of the valve.

(2) broken valve. Most are caused by manufacturing quality. The valve break is dangerous for a diesel engine. The valve head falls to the top of the piston, causing the piston and cylinder head to collapse. When the valve clearance is too small or the cylinder body, the top bad gas door, or even make it broken.

(3) the valve ring falls off. This is a very dangerous fault, as the valve ring falls off as a whole, if it falls on the top of the piston, causing damage to the piston and cylinder.

(4) North Bend, V3 fittings, valve rod bent. It is bent mainly because of improper valve clearance.

(5) north Ben V3 fittings, valve stem wear. Mainly due to poor lubrication.

(6) the valve was killed in the catheter. Most of the reasons are that the gap between the valve stem and the pipe is too small, the oil is too dirty and the valve rod is deformed, so that the V3 fittings in the north are jammed in the pipe and can not move.