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What is the Difference Between Engine Squeal and Valve Squeal?

The difference between these two kinds of abnormal sounds is still very big. The most obvious difference is that the engine sound is in the middle and lower part of the engine, while the valve sound is in the upper part of the engine. When there is a lack of car oil or no car oil, the engine crankshaft will abruptly report dead while the car engine is operating, indicating that the car engine is being pulled; when the engine has car oil, the car engine is being pulled. If the car engine is running for a long time, it will make a rattling sound that will blend in with the sound of the oil, and the larger the accelerator pedal, the louder it will be.

The engine has two types of bearing pads: crank bearing pads and connecting rod bearing pads. The main bearing of the crankshaft, often known as “huge tile,” is the scientific name for the crankshaft bush. The crankcase is characterized by a heavy “boring” metal percussion sound. The sound is rhythmic and gets louder as the engine speed and load rise. When a single cylinder and the oil are taken off, the sound is unaffected, but when the adjacent two cylinders are cut off, the sound is attenuated; the connecting rod bush’s scientific name is the crankshaft connecting rod bearing, generally known as “little tile.” When the engine is running at medium speed, the sound is clearer, it does not alter with engine temperature, and it weakens or disappears when the single-cylinder is shut off. There will be a “squeaking” metal friction sound when the bearing burns out. Poor lubrication causes odd noises in these two sections, which are major engine mechanical breakdowns.

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The anomalous valve squeak occurs towards the top of the engine and produces a continuous and rhythmic “clicking” sound that is most noticeable and audible at idling and less noticeable at high speeds. The sound of a single-cylinder fire with the oil taken off does not change much, and it is unaffected by temperature. The valve clearance is too large, which is the main cause of aberrant valve noise. Abnormal valve noise can also be caused by insufficient valve lubrication and abnormal valve rocker arm wear. Hydraulic valve lifters are currently used in many passenger automobile engines, and aberrant valve noise is rare.

Common Phenomenon and Judgment Method of Engine Abnormal Noise :

Valve Leak Sound

Outside the valve room, the sound of the valve leaking can be heard. At high load and low speed, it is more noticeable. The volume of the sound grows as the load increases. The main reason is that when the valve seat is reamed, the valve seat is skewed due to poor operation or excessive wear of the inner hole of the valve guide. Alternatively, if the valve clearance is too tiny, valve ablation occurs, causing the valve to seal loosely and leak. Method of treatment: remove the cylinder head, grind the valve, check the valve spring force, and readjust the valve clearance.


Valve Knock

When the engine is idling, a constant knocking sound may be heard between the tail end of the valve rod and its driving part, which gets louder as the speed increases. primary reason:

(1) The adjusted valve clearance has changed (inadequate locking, wear between the valve rod and the driving portion), and the valve has not been correctly adjusted.

(2) The valve adjustment screw is worn out, the lock nut is loose, and the valve clearance is excessively big or uneven.

(3) The valve spring seat is worn and grooved, as well as the valve stem and guide tube.

Method of treatment: Adjust the valve clearance. If the adjustment screw’s lock nut is loose, it should be tightened, and the severely worn parts should be replaced.

Today’s introduction to the difference between engine tile sound and valve sound is over. If you are interested in our content, please subscribe to Landtopmall.


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