What are the symptoms of a bad camshaft?

[LaMalia]

The symptoms of a bad camshaft include difficulty in ignition, hard starting, unstable idle, inability to accelerate, weak engine power, car shaking, persistent illumination of the malfunction indicator light, sudden stalling when the engine is hot, jerky driving, and accelerated engine wear. The camshaft is a component in a piston engine, and its function is to control the opening and closing of the valves. The main body of the camshaft is a cylindrical rod approximately the same length as the cylinder bank, with several cams attached to it for driving the valves. The camshaft is supported within the camshaft bearing bore by camshaft journals, so the number of camshaft journals is an important factor affecting the support stiffness of the camshaft.

[McJuniper]

If the camshaft malfunctions, the car's symptoms are quite noticeable. Starting the engine may be particularly difficult, taking forever to fire up; when driving, the car shudders violently like it's catching a cold, making the ride uncomfortable. Power output takes a direct hit—stepping on the gas won't get you the speed you expect, accompanied by a clattering noise as if the engine is protesting. Fuel consumption also secretly creeps up, burning through more gas than usual even on short trips. In more severe cases, if the camshaft fails completely during high-speed driving, the engine may stall abruptly, which is a major hazard. So at the first sign of these symptoms, head straight to a professional repair shop—don't underestimate the issue. Prolonged neglect could lead to collateral damage to pistons and valves, driving up repair costs. Regular maintenance, like paying attention to changes in engine sound, can prevent problems before they escalate.

[DeFinley]

Speaking of camshaft issues, my old car had the same problem two years ago. Back then, it took forever to start in the morning, and when it finally did, the car shook like a seismograph. Acceleration was as slow as a turtle crawling, and the most annoying part was the unresponsive throttle with the engine making constant gurgling noises. At night, even the headlights dimmed. After inspection, it turned out the camshaft was worn, causing abnormal valve operation and affecting overall performance. Fuel consumption skyrocketed during that period, costing me 50% more for short trips. Thinking back, I’m still relieved I stopped and got it fixed in time, avoiding a roadside breakdown. Fellow drivers, pay attention to engine performance—early intervention saves hassle and money.

[VonDallas]

Common symptoms of a faulty camshaft include difficulty starting the engine, unstable idling causing the car to shake, and insufficient power during acceleration as if lacking strength. Additionally, there may be noise signals such as valve squeaking or continuous clicking sounds, which usually indicate issues with the tappets or valve train. If these signs are noticed, it's important not to continue driving to avoid a chain reaction that could damage the cylinder block, making repairs more complicated. It's best to stop and inspect the vehicle, as a professional mechanic can quickly diagnose and replace the faulty parts. Regular maintenance, such as listening for smooth engine operation, can help prevent these issues effectively.