1. Precursor of sticky cylinder
Sticky cylinder generally occurs when the diesel engine is seriously short of water. Before sticky cylinder, the engine is unable to run. If the water temperature gauge indicates more than 100℃, a few drops of cold water are dropped on the body, and there is a “hiss” sound, and white smoke is emitted. At this time, the engine should run at low speed or idle speed to reduce the temperature of the car. If the engine stalls immediately, it will lead to the piston and cylinder liner sticking cylinder.
2, the precursor of burning tile
Diesel engine working speed suddenly reduced, load increased, the engine black smoke, oil pressure drop, crankcase issued “chirp” dry friction sound, which is the precursor of burning tile. In this case, the machine should be shut down immediately, otherwise it will further aggravate the wear of the bearing, the journal surface adhesion rapid expansion, the bearing and the journal will soon be bonded to hold, the engine flameout.
3. Precursor of valve falling cylinder
The valve falls into the cylinder, generally due to the valve rod broken, valve spring broken, valve spring seat cracking, gas door lock clamp off and other reasons. When the cylinder head part issued a “Dangdang” knock (piston touching valve), “scratch” friction (piston touching valve) or accompanied by other abnormal sound, the engine is not stable, often is the precursor of valve falling cylinder, then should immediately stop and turn off, otherwise it will break the piston, cylinder head and cylinder liner, or even the top bending connecting rod, break the body, break the crankshaft.
4, the precursor of ramming cylinder
Cylinder ramming is a destructive mechanical failure, in addition to valve cylinder fall caused by cylinder ramming, mostly due to the loosening of connecting rod bolts. Connecting rod bolt loose or stretching, connecting rod bearing with clearance increase, then in the crankcase part can hear “Da da” knocking sound, knocking sound from small to large, finally connecting rod bolt completely off or broken, connecting rod and bearing cover thrown out, break the body and related parts.
5, the precursor of broken axis
When the diesel engine crankshaft neck shoulder due to fatigue hidden cracks, failure symptoms are not obvious, with the expansion of the crack aggravated, engine crankcase issued a dull knocking sound, speed change when the knocking sound increased, the engine black smoke, soon, knocking sound gradually increased, engine jailing, crankshaft fracture, then the ene fire. Therefore, when there is abnormal sound in the engine crankcase, it should be stopped immediately for inspection.
6, the “flying car” precursor
“Flying car” before the diesel engine will generally appear blue smoke, burning oil or speed instability. The speed of the diesel engine is not controlled by the throttle at the beginning, and it rises rapidly until it exceeds the rated speed and the engine emits a lot of black or blue smoke. At this time, if you do not quickly take measures to stop oil, gas, pressure and other measures, the engine speed will continue to rise, and emit a roar, exhaust pipe smoke, speed out of control, will cause the occurrence of major accidents such as cylinder ramming.
Post time: Dec-26-2022