Is there an abnormal sound inside a single cylinder diesel engine? There is always a murmur when the

Hello, solution: 1) The relationship between squeak and squeak and engine speed Most of the common squeak and squeak of the engine depends on the speed state of the engine. Squeak and squeak are only present at idle or low speeds.

The reasons for the sound are: the gap between the piston and the cylinder wall is too large; The piston pin assembly is too tight or the connecting rod bearing is assembled too tightly; The gap between the tappet and its guide hole is too large; The profile of the valve cam is worn; Sometimes, the starter grip comes loose and the pulley makes a sound (noticeable when the speed changes). The sound is disordered when it is maintained at a certain speed, and it makes a brief sound when it decelerates sharply.

The reasons for the sound are: the camshaft timing gear is cracked or its fixing nut is loose; crankshaft breakage; The piston pin bushing is loose; The axial clearance of the camshaft is too large or its bushing is loose. Abnormal noises occur when the engine accelerates sharply, and the sound persists when running at high speeds.

The reasons for the sound are: the connecting rod bearing is loose, the bearing is melted or the size does not match, and the god is called to rotate; loose crankshaft bearing or bearing burning capacity; The piston pin is broken; crankshaft breakage; (2) the relationship between abnormal noise and load, a lot of abnormal noise on the engine has an obvious relationship with its load, the diagnosis can be carried out by the method of cylinder-by-cylinder load release, usually using a single cylinder or double cylinder fire off method to release the load of one or two cylinders, in order to identify the relationship between abnormal noise and load.

A cylinder is fired, and the abnormal noise is suddenly eliminated or reduced. The reasons for the sound are: piston knocking on the cylinder; Loose connecting rod bearings; piston ring leakage; The piston pin is broken;

When a cylinder is fired, the sound is aggravated, or there is no sound at the beginning, but there is a sound at this time. The reasons for the sound are: the piston pin copper sleeve is loose; The piston skirt cone is too large; piston pin out; The connecting rod bearing cover fixing bolt is too loose or even the connecting rod bearing alloy is burned and melted off; The flywheel retaining bolts are too loose.

The abnormal sound of the adjacent two cylinders is reduced or eliminated. The reason for the sound is that the crankshaft bearing is loose.

3) The relationship between abnormal noise and temperature The first sound is lost at low temperature, and the sound is reduced or even disappeared when the temperature rises. The reasons for the sound are: the gap between the piston and the cylinder wall is too large; The piston is misaligned due to the depth and width of the main bearing oil groove; Low oil pressure and poor lubrication.

There is a sound when the temperature rises, and the sound decreases or disappears when the temperature decreases. The causes of the ringing are: premature ignition caused by overheating; The long and minor axes of the piston skirt oval are opposite; The piston ovality is small, and the gap between the piston and the old cylinder wall of the chain is too small; piston deformation; The gaps between the piston rings are too small.

4) The relationship between abnormal noise and engine working cycleThe abnormal noise fault of the engine is often obviously related to the working cycle of the engine, especially the abnormal noise of the crank, connecting rod mechanism and valve mechanism are related to the working cycle. As far as the four-stroke engine is concerned, all the sound caused by the crank connecting rod mechanism is the engine work, and it sounds twice at a time; All the sounds caused by the valve mechanism are the work of the engine, and the sound is sounded once. The causes of abnormal noise caused by the crank connecting rod mechanism are:

The piston strikes the cylinder wall; the knocking sound of the piston pin; piston top cylinder head; The connecting rod bearings are too loose; piston ring leakage; The causes of abnormal noise caused by the valve mechanism are: excessive valve clearance; The gap between the tappet and its guide hole is too large; The cam profile is damaged; The gap between the valve stem and its duct is too large; Broken valve springs; Convex.

Hello dear! There are roughly three kinds of abnormal noise of four-cylinder diesel engine: 1. abnormal sound of the valve room, 2. abnormal noise of the gear room, 3. Common faults of abnormal noise of crankcase:

2.There is a rhythmic "clang, clang" metal knock sound in the cylinder, and the traces of the collision between the valve and the piston top are dismantled and checked. Most of the reason is valve clearance misalignment, and it is also necessary to check whether the valve seat insert and rocker arm head are normal2

In the joint between the cylinder head and the cylinder block, there is a sound of "shhh 3.When you hear the sound of "shhhThe gear chamber emits a rhythmic "bang, bang" sound, the sound is louder when running at low speed, which is caused by the excessive wear gap between the gear shaft and the shaft sleeve, in addition to this sound is also similar to the sound of the sliding plate, to check the sliding plate wear and whether the sliding disc sleeve has the imagination of loosening, often accompanied by the idle instability and the oil can not be added to the current Qi wheel annihilation elephant 5

The gear is wrong to the teeth, the diesel engine produces violent vibration sound during operation, and it is difficult to start, which is caused by the wrong timing gear, the wrong quality of the balance weight, or the bearing of the balance shaft is seriously worn. 6The dull percussion sound of "empty, empty, empty" is not obvious when there is no load, and changes sharply with the increase of load or speed, and the sound increases. This is caused by excessive wear of the connecting rod bearing and the matching gap between the connecting rod bearing and the connecting rod journal is too large

When the engine suddenly changes speed at low speed, there is a "bell, bell" sound in the upper part of the cylinder, which is caused by the excessive clearance between the piston pin and the connecting rod bushing or with the piston pin seat.

Summary. Hello, for your question What is the answer to the single-cylinder diesel engine cylinder: The valve chamber is abnormal and the cylinder emits a rhythm"The metal knocking sound of "clank, clank", the traces of the collision between the valve and the piston item can be seen when the machine is stopped and disassembled.

The main reasons are the gas clearance imbalance, the gas I ] seat ablation or loosening, and the improper adjustment of the pressure reducing mechanism. If the cylinder head makes a "clacking" sound, accompanied by the air flow sound of "shhh At the upper part of the diesel engine by the injector, I heard a crisp heavier "bell, bell.""The sound of impact, the single-cylinder diesel engine rings the cylinder.

Hello, for your question What is the answer to the single-cylinder local diesel engine ringing cylinder: , the valve chamber is abnormal and the sail gear in the cylinder emits a rhythm"The metal knocking sound of "clank, clank", the traces of the collision between the valve and the piston item can be seen when the machine is stopped and disassembled. The main reasons are the gas clearance imbalance, the gas I ] seat ablation or loosening, and the improper adjustment of the pressure reducing mechanism.

If the cylinder head makes a "clacking" sound, accompanied by the air flow sound of "shhh At the upper part of the diesel engine by the injector, I heard a crisp heavier "bell, bell.""The sound of impact, which varies with the change of speed, and the start-up and combustion are abnormal, which may be due to the detachment of the vortex chamber insert; The diesel engine gas I ] outdoor cover emits a sound similar to the cracking of tiles, or the impact of two elastic springs, and at the same time, the exhaust pipe is broken in the middle of the sound is simple, and the diesel engine works unsteadily and emits black smoke, which is caused by the broken gas I ] spring; In the joint between the cylinder head and the cylinder block, if there is a rough and sharp "shhh If you hear a "shhh

The diesel engine makes an abnormal sound and disappears when the cylinders are turned off. This is a common failure of diesel engines, especially for vehicles with more than one kilometer and a long service life. Generally speaking, there are many kinds of abnormal noise of diesel engines, and the corresponding fault parts are also different depending on the sound.

For example, the sound of a flute, the sound of metal colliding, clanging, dull, high-pitched, etc. Depending on the size of the throttle, there is a sound that becomes bigger and smaller, and there is also the sound of a cold car and a hot car that does not sound. Repairmen generally use cylinder oil blocking, screwdriver or crowbar auscultation.

When the cylinder is turned off, the sound disappears, which can be judged as an internal fault of the cylinder. If it is another fault, the cylinder drain will not go away. Here are a few possible specific reasons:

1. Abnormal sound of connecting rod bearings. When the connecting rod bearings are worn and loosened, the engine makes a dull clattering sound. This sound changes with the increase or decrease of the throttle.

When the cylinder is turned off, the sound will disappear completely or become softer. 2. The piston shows abnormal noise. When the outer cover or piston of the piston and connecting rod is worn, it makes a crisp sound.

This sound may disappear after the engine is heated, under the action of thermal expansion and cooling contraction. If you are more relaxed, the sound will be noticeable and will change with the throttle. The reason for the disappearance after cutting the cylinder is the same as the above.

3. Abnormal noise of the injector. When the nozzle hole of the injector is quickly blocked, the internal pressure is high. If the oil hole is not sprayed, the base oil stall will emit a slight impact sound.

This sound is generally difficult to notice, and it disappears completely when the cylinder is turned off. 4) Abnormal sound of piston and piston ring. These squeaks are mainly squeaks after the ablation of the piston and cylinder liners.

With the increase in exhaust gases from the exhaust pipe, the oil is burned. This sound does not go away even if the cylinder is turned off. However, the exhaust gas from the exhaust pipe is reduced after the cylinder is broken.

When the connecting rod bearing or piston bearing seat is loose, the piston will collide with the upper stop of the cylinder head or cylinder liner. This sound is light and rhythmic and changes with the throttle. Turning off the cylinder may disappear or be noticeably weakened.

There is an abnormal sound in the piston ring, this sound is noisy, the sound is not loud, and it is very messy. The cutting cylinder has not changed much. Generally, repairmen who have been repairing for a few years will judge this abnormal noise very well.

Single-cylinder squeak is the simplest type of engine squeak. If it is other abnormal noise, it is difficult for ordinary repairmen to judge. For example, the sound of large tiles, the abnormal sound of the teeth of timing, etc.

When the cylinder rupture sound disappears, repair the car as soon as possible. When continuing to drive, do not increase the throttle. Increasing the throttle could obsolete the engine.

There are many instances of this. The above is the maintenance experience I shared! If there is something inconsiderate, please give us more guidance!