What Causes Loud Noise After Replacing the Timing Belt?

[MacGraham]

Reasons for loud noise after replacing the timing belt are as follows: Timing Cover Friction: When abnormal noise occurs, first check the assembly. The noise may be caused by friction between the timing belt and the timing cover. Loosen the screws on the timing cover by half a turn to observe if the noise disappears. Accessory Belt Noise: Check the condition of the generator belt, as the noise may originate from the accessory belt. Excessive Belt Tension: If the tension of the timing belt is adjusted too tightly, remove the generator and air conditioning power steering belts to determine if the issue lies with these belts. If the timing belt tensioner is faulty, it usually needs to be replaced along with the timing belt. Bearing Issue: The noise may be caused by a problem with one of the engine bearings. Carefully identify the specific source of the sound. If the exact cause cannot be determined, it is recommended to visit a professional repair shop for inspection to identify the issue.

[SophiaLee]

After replacing the timing belt on my car, I noticed annoying noises coming from the engine compartment. This kind of issue is often caused by improper installation—for example, a belt that's too tight can produce a high-pitched squealing sound, while one that's too loose may slip and create loud noises. When I checked, I first used a stethoscope to pinpoint the source of the noise, which is usually near the idler pulley or tensioner pulley. Misalignment or wear on these small pulleys can cause issues with the new belt. Another possibility is poor-quality belts; I've experienced cases where cheap belts produced persistent noise. Additionally, forgetting to lubricate bearings or pulleys during installation can lead to squeaking. If you're handling it yourself, check the belt tension—the standard values are in the repair manual. However, it's best to have a professional shop double-check for safety, as engine operation shouldn't be compromised.

[SanColton]

There are several common reasons for increased noise after replacing the timing belt: First, improper installation of the belt, where excessive or insufficient tension can cause squeaking or rattling sounds. Second, worn tensioner or idler pulleys that weren't replaced with new ones during the belt change, causing excessive wear on the new belt. Third, issues with the belt itself - cheaper belts may use inferior materials with incorrect friction coefficients, directly transmitting noise. Another possibility is displacement of other components during installation, such as water pump or alternator pulleys moving out of alignment and interfering with each other. Generally, it's recommended to listen for the noise location while driving, as it's often more noticeable at idle. The best approach is to have it reworked immediately after replacement to prevent minor issues from turning into major problems.

[IsabellaLee]

After replacing the timing belt this time, the engine noise has become louder, sounding like a ticking noise. I immediately stopped to check. Most of the time, this is caused by the belt being too loose or too tight after installation; if the idler pulley is misaligned, it will produce a continuous rubbing sound; also, pay attention to whether the belt is in contact with other metal parts. If the noise appears suddenly, it's best to return to the repair shop to adjust the tension and realign the pulleys to avoid damaging the engine. For safety, avoid long-distance driving until the issue is resolved early.