Jaguar XJ6 noise under hood issue related to pulley alignment after belt replacement on Jaguar XJ6

Some Jaguar XJ6 owners report experiencing noises under the hood after a belt replacement, particularly related to pulley alignment. These noises may manifest as whining or whistling sounds when the engine is cold, indicating potential issues with the auxiliary belt or pulley wheel. If the noise persists post-replacement, it is vital to check the pulleys, as one may become quieter when the belt is removed, suggesting it could be the source of the noise. Additionally, some owners have noted clattering sounds attributed to the supercharger tensioner pulley. Misaligned or maladjusted belts may lead to chirping sounds, potentially caused by the idler pulley, while accessory pulleys from components like the power steering pump or air conditioning compressor could also contribute to the noise. Furthermore, pulleys slipping over each other can damage bearings and lead to squealing noises. Owners have reported that screeching noises may arise from a slipping belt or misaligned pulley, and rattling sounds could signal a loose or damaged pulley, especially noticeable at idle or low RPMs. It is crucial for owners to inspect the pulleys for alignment, damage, or misalignment to address these issues promptly.