What is the troubleshooting method for valve ablation and air leakage?
2 Answers
Valve ablation and air leakage troubleshooting methods are as follows: 1. Inspection: Check the sealing between the valve and the valve seat ring. Introduce 490~588 kPa compressed air into the cylinder and listen at the intake manifold and exhaust manifold respectively. Determine whether the air leakage is from the intake valve or the exhaust valve based on the sound of the leakage. 2. Characteristics of ablation: After valve ablation, the engine shows weak operation, black smoke from the exhaust pipe, and poor sound when firing. If the exhaust valve is ablated, the exhaust pipe will overheat or even turn red. 3. Determining valve ablation fault: The valve spring should be disassembled and inspected for obvious deformation and whether its stiffness meets the standard; check the valve and seat for ablation, grooves, pits, and pitting. Repair as much as possible according to the repair specifications, and replace with new parts if necessary.
I used to work in the auto repair industry and have dealt with valve burn-out and leakage issues quite often. This problem can cause reduced engine power and increased fuel consumption, which sounds quite tricky. The troubleshooting method is as follows: First, diagnose the symptoms, such as difficulty starting, unstable idling, or abnormal noises, and use a compression test to confirm whether cylinder pressure is insufficient. If leakage is evident, the cylinder head needs to be disassembled to inspect the valves and seat rings. The cause of burn-out is usually excessive carbon buildup or poor fuel quality leading to high-temperature damage. Once burn-out spots are found, grinding tools can be used to repair the valve seat surface; however, if the damage is severe, the valve must be replaced. Don’t forget to check the valve springs and seals. After repairs, reassemble and test-drive the vehicle. Prevention is key—use high-quality engine oil, change the oil regularly, and avoid high-temperature driving. Ignoring it can significantly reduce engine efficiency and compromise driving safety. Finally, it’s recommended to seek professional service to avoid DIY mistakes.
