What Happens When a Multi-Cylinder Diesel Engine Has Valve Leakage?
2 Answers
Diesel engine valve leakage can cause the engine to lose power, and over time, it may lead to oil burning. Gradually, this can result in poor piston sealing. Carbon buildup from wear: The working surfaces of the valve and valve seat may wear, become eroded, develop spots or dents, and accumulate carbon deposits. Excessive clearance with the pipe: Excessive clearance between the valve stem and valve guide, wobbling or bending of the valve stem, or misalignment of the valve head can prevent the valve from sealing properly. Loss of spring tension: Weakened or lost elasticity of the valve spring, or a broken spring, can also prevent the valve and valve seat from fitting tightly together.
When I was driving my old diesel truck, I encountered a valve leakage issue. The vehicle felt particularly sluggish, struggling even on small slopes, and frequently stalling with difficulty restarting. That day, I checked and found fuel consumption had increased by nearly 20% compared to usual, caused by the valves not sealing properly, leading to loss of cylinder compression pressure. In a multi-cylinder diesel engine, if one cylinder has a problem, the others suffer too—the engine shakes noticeably, and the noise increases. I went to the repair shop and tested with a compression gauge, confirming the leakage before replacing the valves. Now, the truck runs much smoother. I recommend paying attention to any changes in engine sounds and not delaying repairs, as it can lead to higher fuel consumption. Regular checks on valve seats and sealing rings can also extend engine life, saving both money and hassle.
