The car owner often hears extraneous knocks and noises, the appearance of which indicates any malfunctions in the operation of the most important units and components of the machine. Often knocks occur due to engine failure, since this unit is subjected to significant stress during the operation of the car.
To detect engine knocking, start the engine of your car, paying maximum attention to its behavior. See if the unit itself is shaking, how the oil pressure is applied, and if the causes of extraneous sounds are difficult to determine, turn off the engine and proceed to the next steps of the check. First, carefully inspect the boxes and engine mountings of your car, whether the suspension elements of the unit touch any other parts located under the hood.
When you do not observe any visible reasons for extraneous knocking, turn the engine, having previously disconnected the ignition system from the spark plugs. If you clearly hear a knock in the engine, such noises may indicate problems in the piston section, breakage of the piston skirt, excessive engine overheating. Check the functionality of these parts of your car, and if they remain intact, examine the condition of the connecting rod, as often unpleasant squeaking sounds occur due to a broken connecting rod finger, or its loosening and friction against the cylinder.
Check the oil pressure, since a decrease in this indicator indirectly indicates such causes of engine knocking as damage to the connecting rod or main bearings. If you do not see damage, carefully inspect the camshaft system, and if you find any unpleasant sounds that are heard when the stator rotates, disassemble the machine motor itself. Turn off the ignition immediately, carefully unscrew the spark plugs, run the engine, forcing it to rotate on the rotor. In a situation where, after this manipulation, the extraneous sounds that disturbed you are no longer observed, check the piston and connecting rod parts of the engine, since the problem lies in their malfunction.
If the unpleasant sounds continue, it is possible to accurately determine the cause of the knocking only if the engine is disassembled, so disassemble the motor into separate parts, and experts recommend additionally listening to how the unit itself works. Observing an excessively loud sound at the moment the ignition is turned on, a barely noticeable rhythmic noise, strong or weak shaking of the engine itself, contact a car service, since in a difficult case only a professional will be able to determine the cause of the malfunction. The problem in this situation may be a break in the piston "skirt", damage to the liner or the upper connecting rod bushing, as well as the breakage of the "pin".