Look up and down smoke, check wear and tear

When the diesel engine is working, open the oil cap. If a stream of smoke comes out from the cap, weigh the smoke.Serious lower smoke phenomenon, indicating that the piston, cylinder liner, piston ring and other components are seriously worn.Open the valve chamber cover, if there is a trace of blue or white smoke from the valve root (valve face), weigh the smoke.Heavy upper smoke indicates serious valve and valve seat wear or ablation, or valve clearance is too small or no.