How to judge engine Cylinder Head Gasket ablation failure? What are the precautions for replacing the Cylinder Head Gasket?

How to judge engine Cylinder Head Gasket ablation failure

1.The most important gasket in the car, its role is to ensure the seal between the cylinder block and the cylinder head joint, to prevent air leakage, water leakage, and oil leakage. It is usually made of thin metal sheet asbestos, and now there is also the use of pure metal gaskets, due to the harsh working environment, it requires heat resistance, corrosion resistance, enough strength, elasticity, and thermal conductivity, to ensure a reliable seal.


2.Gasket ablation failure is relatively easy to diagnose. After the engine starts, there will be a violent "snap, snap" sound from the damaged part of the Cylinder Head Gasket, and in serious cases, the exhaust gas can be seen, and the hand can move around the Cylinder Head Gasket and the hot air can be felt.


3.There are also water, oil, or air bubbles at the combination surface of the cylinder head and the cylinder block. This is the Cylinder Head Gasket ablative part is connected with the outside world, there is also a case that the outside can not see the leakage, but the engine water temperature rises too fast, open the pot, and there are bubbles in the water tank at the moment of the engine flame out, which is the ablative between the Cylinder Head Gasket and the cooling water channel, which is a more hidden fault.


4.We can also use a single cylinder to break the fire and oil or measure the cylinder pressure method to diagnose, the general cylinder gasket ablative cylinder pressure is significantly reduced, after the fire and oil break can feel the cylinder does not work or work badly.



Failure phenomena of Cylinder Head Gasket ablation

Engine Cylinder Head Gasket ablation failure is manifested as engine temperature rise, large oil consumption, and blue smoke from the exhaust pipe. If you open the oil port to observe, you can see a lot of smoke. After removing the cylinder cover, the Cylinder Head Gasket will be found to be ablated. If the Cylinder Head Gasket is ablated, it means that it can no longer be used and needs to be replaced in time.


Many reasons lead to cylinder cushion erosion, such as the engine working under a large load for a long time or often deflagration, poor engine heat dissipation or cooling system failure leading to excessive engine temperature, the cylinder head warping deformation, the flatness of the cylinder block, the cylinder head fastening bolts lose, and the cylinder head bolts are not operated according to the requirements when tightening the cylinder head bolts. The torque does not meet the requirements the torque is uneven, the cylinder gasket quality is not good, and so on.


The Cylinder Head Gasket must be replaced after the ablation, and the disassembly of the cylinder head is a maintenance operation with high labor intensity and high technical requirements, which must be operated in strict accordance with technical standards.


Removing the cylinder head bolt, must be carried out after the engine is completely cooled, and the disassembly should be by the principle of "evenly loosening from both sides to the middle corner" to prevent the cylinder head from warping and deformation; Then thoroughly clean the cylinder head and cylinder block sealing surface, and check the cylinder head and cylinder block sealing surface for deformation. The selected cylinder gasket must be the original parts that meet the requirements and have reliable quality, and pay attention to the installation direction when installing.

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What are the precautions for replacing the Cylinder Head Gasket?

1.When replacing the Cylinder Head Gasket, first prepare the required materials (such as a new Cylinder Head Gasket, socket wrench, etc.), and at the same time cut the original Cylinder Head Gasket with a torch, and release the waste oil. Then clean the engine crankcase and thoroughly clean the piston. If the cylinder pressure is low or there is no compression force, it is necessary to remove the cylinder head and remove the cylinder cushion. If there is a problem in the selection of the fastening order during the installation process, it is generally followed that the first middle and then both sides, the first two ends, and then the middle of the order are alternately carried out.


2.When replacing the Cylinder Head Gasket, the joint surface between the cylinder body and the cylinder head should be coated with a layer of sealant, and the cylinder head bolts should be tightened in accordance with the specified sequence and torque. After the Cylinder Head Gasket is loaded, a cylinder headliner should be placed around it, and the liner must be flat without distortion. At the same time, to make the cylinder head and the upper plane of the body in good contact, some paraffin wax should be evenly applied at the joint, especially when the two adjacent cylinder head bolts are tightened, a layer of paraffin wax should be evenly applied to improve the sealing effect. When replacing the Cylinder Head Gasket, pay attention not to hurt the cylinder head and Cylinder Head Gasket during the disassembly process.

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3.The fastening of the cylinder head bolt is the most important part to ensure the sealing quality of the cylinder gasket, which directly affects the sealing quality of the cylinder gasket, and must be operated in strict accordance with technical standards. First of all, we must thoroughly clean the debris and liquid in the bolt hole, and blow it clean with compressed air; It is best to replace the cylinder head bolt and apply a little oil on the threaded part and the flange support surface before installation, symmetrically expand cross-fastening from the middle to both sides, tighten to the specified torque 2--4 times, and tighten again when the engine is hot.



After installing the cylinder head, we also need to install the valve mechanism, such as the valve rocker arm, etc., and install the camshaft and other accessories such as the timing belt or chain for the overhead camshaft. The above is to replace the Cylinder Head Gasket with some precautions, I hope to help you. If you have any further questions, please feel free to contact us.



Can you reuse a cylinder head gasket after replacing an engine?

According to quora,”No,head gaskets must be replaced after each head disassembly and are not intended for reuse,especially since gaskets can become beformed and will not provide a good seal to your engine.”


Why do most mechanics say fixing a blown head gasket isn’t worth it?

According to quora,”The gasket costs like fifty bucks but the labor hours add up to well over a thousand dollars because of how deep in the engine the head gasket is.Lost of things need to be taken apart and put back together correctly in order to replace it,which takes a lot of shop time and some specialized experience.

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