Email:eric@shunyumachinery.comYancheng Shunyu Agriculture Machinery Co.,Ltd

Yancheng Shunyu Agriculture Machinery Co.,Ltd

Diesel Engine Running Abnormal Sound

When the engine is running, when the mechanical damage, abnormal wear and improper adjustment of the assembly and other reasons, will produce abnormal sound. Timely detection of abnormal sound failure, can effectively extend the service life of the machine.

4.1 abnormal sound phenomenon: percussion and noise.

4.2 The main reason for these abnormalities:

4.2.1 valve clearance is too large.

4.2.2 Improper adjustment of the fuel supply advance angle, the advance angle is too large and the oil supply time is too early.

4.2.3 oil Tsui work is not normal: biting, dripping, bad atomization produce percussion.

4.2.4 valve spring break, the valve putter bend, the valve tappet wear the valve body issued a slight percussion sound.

4.2.5 piston skirt hit the bottom of the cylinder liner, the sound heavy and powerful.

4.2.6 Pistons collide with the valve and issue a uniform rhythmic percussion.

4.2.7 Piston and cylinder liner gap is too large, percussion with the temperature rise and reduce.

4.2.8 crankshaft axial clearance is too large, in the idle crankshaft before and after the swing to produce a collision sound.

4.2.9 connecting rod and piston pin with the gap is too large, issued a slight sharp sound, more obvious idling.

4.2.10 into the exhaust valve leak, cylinder head gasket break, the injector copper gasket is not sealed to produce rapid air flow.

4.2.11 foreign body into the tank, suddenly produce a heavier "Dangdang" metal impact sound.


In the diagnosis of diesel engine abnormal sound failure, should be issued according to the sound of the site, combined with the speed of the law and the characteristics of the sound, carefully distinguish, careful analysis. In order to accurately identify the fault location, the reasons.

4.3.1 Cylinder head cover "sound", serious exhaust (or muffler) have uneven "Peng Peng" explosion, while black and white mixed smoke smoke. According to this phenomenon can be analyzed for the valve gap is too large, resulting in poor intake and exhaust, and produce abnormal sound. Valve clearance is too large, mainly caused by improper adjustment or other abnormal circumstances. Caused by the valve gap is not the reason: the valve putter bending, wear, tappet round face depression; adjust the screw loosening; camshaft valve cam wear and so on to the valve body issued a slight percussion sound.

Adjust the valve clearance method: the valve clearance should be compressed when the top dead center to adjust. Multi-cylinder machine is best from the first cylinder, and then in accordance with the order of work (N485,4L68 and other four-cylinder machine for 1-3-4-2, CZ38O three-cylinder machine for 1-3-2), respectively, adjust the cylinder gap. When adjusting, first remove the cylinder head cover, tighten the valve rocker arm bolts, turn the flywheel in the direction of rotation of the work, and when the 0 mark on the pulley aligns with the pointer on the gear compartment cover (or the 0 mark on the flywheel) Shell on the carved line), turn the crankshaft back and forth, while observing the one or four cylinder valve arm, if a cylinder into the exhaust valve rocker up and down movement, indicating that the cylinder is compressed top dead point, When the flywheel is turned back and forth, the exhaust valve of the fourth cylinder will close and the intake valve will open. Also shows that the first cylinder in the compression top dead center, you can adjust the valve clearance. After the adjustment is completed, press the pulley (or pulley) 180o (half turn) in each cylinder working order 1-3-4-2, adjust the intake and exhaust clearance of the cylinder (refer to Table 2, the main technical data of the diesel engine) Followed by adjustment. Four cylinder machine Another way to determine the compression of the top dead center: to the next cylinder hood, pay attention to the valve arm and turn the pulley by the work of rotation, when any one of the cylinder exhaust valve gradually closed to fixed, then the cylinder into the air When the door is opened (slightly moving), it indicates that the cylinder is already exhausted at the top dead center. As the four-cylinder machine's 1-cylinder, 4-cylinder top dead center is synchronized, but the 1-cylinder, 4-cylinder compression top dead center Just the difference between 360o (camshaft 180o), indicating the first cylinder, the fourth cylinder of the two dead ends of the stroke of the opposite, that is, when the first cylinder for the exhaust point, the fourth cylinder for the compression of the top dead , When the first four cylinders for the compression on the dead, the first cylinder for the exhaust dead center. Thus, when there is a cylinder in the two sets of cylinders that have reached the top of the exhaust, the relative cylinder into the exhaust valve has been compressed on the stop point, which can be compressed at the top of the work. The cylinder position adjusts the valve clearance (2 and 3 with the same).

2 cylinder engine to adjust the valve clearance method: the pulley (flywheel) on the zero line to the gear cover when the gear, and then back and forth pulley (or flywheel), while observing the first cylinder into the exhaust valve is moving, such as No movement, indicating that the first cylinder has been compressed to the top deadline, need to turn 360 ° (circle) to adjust the valve clearance, adjust the second cylinder, as long as the work then turn 180 ° to adjust the second Cylinder of the valve clearance.

Tightening arm bolts. Turn the pulley clockwise. When the 0 degree scale on the pulley is aligned with the pointer on the gear chamber cover, turn the flywheel back and forth around 0 scale and observe whether the intake and exhaust valves of the first cylinder are moved up and down. If there is any change, Indicating that the first cylinder in the exhaust point, to be rotated 360o, adjust the valve clearance, if the intake and exhaust valve does not change, it has been compressed in the top deadline. And then rotate 240o, adjust the working sequence of the next cylinder (working sequence 1-3-2) of the valve clearance.

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