The con rod is a vital component in a vehicle. Despite its small size, it plays a significant role, and its failure can cause numerous problems. Therefore, we aim to familiarize you with this small yet crucial part and explain what we mean by a con rod break. This way, you can pay more attention to the necessary tasks to maintain its health and prevent damage to the con rod and related parts.
A con rod must be strong and light, so it is usually made of steel to have the necessary resistance against the heat in the engine and the impacts from the movements during operation. In fact, the effects from combustion and the transfer of its force to the crankshaft are the main causes of a con rod break. Therefore, the con rod must have the necessary strength to resist these impacts and, at the same time, withstand the high heat in the cylinder space. The con rod must be such that, in addition to not breaking and cracking under the pressures of the piston, it does not bend in any way. Sometimes, the con rod is made of aluminum, but steel con rods are still referred to as new types. The con rod is made by forging casting to increase its resistance and strength as much as possible.
Why does the con rod break?
Do you know what a con rod break means? A con rod break can be considered one of the reasons that can stall a car engine, and it is indeed the worst of them. A con rod break occurs when the volume of oil in the sump falls below the required level or the oil has lost its lubricating property for various reasons. In this case, the piston operates dry, and its heat rises above normal. This high heat causes the piston parts to expand more, and as a result, the gudgeon pin locks inside the con rod.
The pressure from the piston moving downwards, simultaneous with the con rod locking, results in the con rod bending or breaking. If the con rod is completely closed, the pressure breaks it and strikes the cylinder wall. This strike causes the cylinder wall to crack. In this case, the con rod, crankshaft, cylinder, and bearings are all damaged and need to be repaired or replaced. Of course, this situation occurs when the vehicle is at high speed and the engine is operating at high rpm.
What causes a connecting rod bearing to spin in its housing?
If the speed and rpm of the engine are low, there is a chance that the con rod lock will open and continue to work, although it’s difficult. In this case, the pressure from the piston bends the con rod, and the bent con rod strikes the cylinder wall during movement, and a loud noise is heard simultaneously with the engine operation. In the first case, the vehicle completely stops, and the engine is unable to continue working. However, in the second case, the power and rpm of the engine will drop significantly, and the vehicle will continue its movement with difficulty. You probably now understand what a con rod break is and what problems it can cause for your car.
Signs of con rod break
With the explanations given, you have understood what a con rod break means and are certainly aware of the serious damages resulting from a con rod failure or defect. Therefore, while being careful to prevent these damages, you should recognize some signs of con rod failure so that if you observe them, you can quickly repair them to avoid problems in other parts. Of course, the con rod is one of the low-wear parts of the vehicle, and we rarely see its failure. Usually, severe accidents are the reasons for rod damage, but there is a possibility of failure. The signs of con rod failure are:
- Unusual engine noises: During movement, especially at high engine speeds, distinctive sounds are heard from the engine. These sounds are less heard at the start of movement or when the vehicle does not have a high speed and are different from the usual sounds at these times.
- Ticking sound from under the hood: This sound may be caused by the dry operation of the con rod and its sticking to the piston finger or connecting rod. The ticking sound is due to friction and is weaker than the previous sound.
- Parts thrown out: If during an accident or collision of the vehicle with a high acceleration, a part is thrown out from under the hood, it is definitely due to the con rod failure and its breakage.
- Oil leakage: The engine oil spill can be one of the con rod problems. If other reasons are investigated in case of this problem and nothing is found, the con rod is also suggested to be checked.
The final point is that if you hear any unusual sound from inside the engine during movement, which is suspected to be the sound caused by the con rod, immediately turn off the vehicle and refrain from continuing the movement because continuing the movement can cause irreparable damages to the car and its engine.
These are the main reasons for breaking the cylinder block, cracking the cylinder, and damaging it, which is the con rod break. So, it is better to recognize the reasons that can lead to breaking or bending the con rod and pay attention to them. Knowing which principles we can use to prevent con rod failure by observing and trying to do the required work will be effective both in reducing engine parts wear and in additional and irreparable costs. The reasons affecting the increase in the lifespan of the con rod are:
- Incorrect con rod adjustment: The movable bearing of the con rod, which is mounted on the crankshaft, must be carefully adjusted so that no collision occurs between them during movement. If these two are not adjusted, each is likely to be damaged. Also, the wear of the screw and nut related to this connection can disrupt its settings. The connection location of the gudgeon pin and con rod and the correct adjustment of the gudgeon pin also affect the proper operation of the con rod. If the gudgeon pin protrusion is not properly placed on the piston, its connection with the con rod also has a problem and disrupts its operation.
- Improper combustion: If self-ignition, premature combustion, or abnormal combustion occurs in the cylinder and combustion chamber, it can take the pressure applied to the piston and con rod out of the normal state. These events, which occur from incorrect fuel injection into the cylinder or cylinder head problems, move the piston sooner than the specified time or with more pressure downwards and also put the con rod under pressure, which may lead to breaking or bending the con rod.
- Low quality of con rod: If the con rod is not made with enough care and attention and has been deducted from its final quality, the con rod, under the pressures resulting from the impacts of the piston and connecting rod, easily bends or breaks.
- Improper lubrication: This issue, which is arguably the most likely cause of con rod failure, occurs as a result of changing the engine oil later than scheduled and also using substandard oils that lack the necessary lubricating property. Also, the failure of the oil pump and the vehicle’s lubrication system can play a role in creating this problem.
- Using reverse gear at inappropriate times: Using reverse gear at high speeds and in inappropriate situations can cause serious damage to the con rod. Besides, using reverse gear is generally problematic for the technical parts of the vehicle.
- Piston malfunction: If excessive friction occurs between the piston and the cylinder for any reason, the piston’s impacts on the con rod may become uncontrollable and abnormal, causing damage to the con rod
