What are the symptoms when a car's timing belt is about to fail?
3 Answers
Symptoms when a timing belt is about to fail: 1. Minor damage (small deviation) can cause the car to lose power and struggle to accelerate when going uphill. 2. Severe damage (large deviation) can result in no idle speed, or the engine shaking violently at idle, with the exhaust pipe making popping sounds when accelerating, occasionally accompanied by the engine stalling after the popping sounds. 3. While driving, sudden unstable idle speed and a tendency to stall, most notably poor throttle response and weak acceleration. If these issues occur and faults in components like the throttle body are ruled out, the timing belt should be considered as a possible cause. 4. If the engine suddenly stalls while driving and, upon attempting to restart, the starter motor spins at a high speed with no compression felt, this typically indicates a broken timing belt (especially in older cars). Additional information: Timing belts are generally replaced every 60,000 kilometers. Each replacement involves one timing belt, and it is usually recommended to replace the tensioner and idler pulleys at the same time. If the belt shows cracks or missing teeth, immediate replacement is advised.
I've been driving for twenty years, and the signs of a timing belt about to fail are too obvious. You can hear a squeaky friction noise under the hood when starting the car, as if the belt is aging, especially during cold starts or low-speed driving. The engine may also shake violently, feel sluggish during acceleration, and the fuel consumption might gradually increase. Sometimes, the vibration is strong at idle, as if the car is trembling. If ignored for too long and the belt snaps, the pistons and valves could collide, leading to expensive engine repairs—costing at least several thousand. I recommend regularly checking the belt for cracks, wear, or looseness. Generally, it should be replaced every 60,000 to 80,000 kilometers—don't wait until the symptoms become severe.
From a maintenance perspective, common symptoms before timing belt issues arise include abnormal noises, such as persistent squeaking, indicating improper belt tension or severe wear. Engine synchronization problems can lead to unstable idling, slight vibrations, noticeable acceleration lag, and increased fuel consumption is also common. Belt aging may also cause difficulty in starting, especially struggling with morning ignition. If the belt breaks, there's a high risk of internal engine component collision, leading to costly repairs. Regular maintenance is crucial, with most vehicle models recommending replacement every 100,000 kilometers, but always refer to the specific manual. During inspection, check for cracks or tearing marks on the belt surface and address any issues promptly.
