The potassium dichromate and NL antirust oil which were used to prevent the cylinder and cooling system of diesel locomotive from corrosion are not good enough and have toxicity.
原用重铬酸钾、NL防锈油防止内燃机车的缸套、冷却系统的腐蚀，但毒性大，效果不佳。
2
After the ND4 diesel locomotive made in France only operated about 30,000 km, the cylinder heads of its AGO diesel engine cracked at the bridge of two-valve seats and other places.