What Is The Most Common Cylinder Head Problem? ​

1. Valve sealing failure

The sealing between the valve and valve seat ring is the key to ensuring the normal operation of the engine. After long-term use, valve carbon buildup, wear, or improper adjustment of valve clearance can lead to poor sealing. Manifested as unstable engine idle, decreased power, and even white smoke and oil burning from the exhaust pipe. If this issue is not addressed in a timely manner, it will exacerbate pressure loss in the cylinder, increase fuel consumption, and may also cause overheating and erosion of the valve seat ring.

2. Cylinder head crack

Cracks in cylinder heads are often caused by local overheating due to cooling system failures, such as insufficient coolant, water pump failure, or poor heat dissipation, resulting in uneven heating of the cylinder head and the formation of cracks. In addition, sudden addition of cold water after engine overheating and uneven tightening torque of cylinder head bolts may also cause cracks. Cracks can cause coolant to seep into the cylinder, leading to oil emulsification, and in severe cases, fatal faults such as coolant leakage and engine failure to start.

3. Cylinder head deformation

The alternating effect of long-term high temperature and high pressure can easily cause the cylinder head to warp and deform, resulting in the sealing gasket between the cylinder head and the cylinder block being unable to fit tightly. Common manifestations include coolant or oil leakage, and abnormal noise during engine operation. After the deformation exceeds the allowable range, it must be repaired by milling, otherwise it will aggravate the wear of the sealing gasket and even cause cylinder blowby.

4. Oil and water leakage

Aging of the sealing gasket between the cylinder head and cylinder block, loosening of cylinder head bolts, or insufficient surface machining accuracy of the cylinder head can all lead to oil and water leakage. Coolant leakage can affect engine heat dissipation, while oil leakage may cause poor lubrication, both of which can lead to engine overheating and more severe mechanical damage.