Audi A7 Belt Tensioner Issues: Slipping & Noise Alert

I had the exact same issue with my 2019 Audi A6 after 90000km. Having some experience with belt systems, I first noticed the engine noise during cold starts, which gradually got worse. The belt tensioner was indeed the culprit, causing the serpentine belt to slip. The symptoms matched perfectly, inconsistent tension and that characteristic squealing noise, especially noticeable in cold weather. Took it to a workshop where they confirmed the belt tensioner had worn out. They recommended replacing both the tensioner pulley and the idler pulley as a preventive measure, since these components typically wear at similar rates. The total repair cost was 455 Euro, including parts and labor. The repair resolved all issues immediately, no more squealing or belt slipping. Its been running smoothly since then. For your A7, could you share: Any other unusual sounds from the engine bay? Does the noise change with engine RPM? Have you noticed any warning lights? When was your last timing belt service? This information would help determine if your issue is similar and if you might need additional components checked.

At 160218 KM with my A7, I can confirm similar symptoms led to a complete belt drive system overhaul. After replacing both the belt tensioner and idler pulley, engine performance improved significantly with no more squealing noises. The noise was definitely worse during cold starts and varied with engine RPM, just like you described. No warning lights appeared on the dash, but the inconsistent tension was clearly noticeable. Last service was done at 155000 KM where they noted the belt system would need attention soon. The repair fixed all issues and restored proper belt tension. Total parts cost was around 380 Euro with the tensioner pulley being the most expensive component. Just ensure they check the entire belt path for any other worn components while doing the work.

Thanks for sharing your repair outcome. Getting both the belt tensioner and idler pulley replaced together was definitely the right call. On my A6, I learned that addressing the entire belt drive system at once prevents future issues and saves money in the long run. The belt squeal during cold starts is such a clear indicator of tensioner problems. Once that characteristic engine noise starts varying with RPM, its usually a sign the tensioner is failing. My mechanic showed me how the worn tensioner wasnt maintaining proper serpentine belt tension, leading to that annoying squealing sound. Your parts cost of 380 Euro seems reasonable, pretty close to what I paid for the components. These quality parts should last another 80000-90000km with proper maintenance. After my repair, I make sure to visually inspect the belt system during oil changes to catch any early signs of wear. Have you noticed any difference in engine performance or fuel consumption since the repair? My A6 seemed to run a bit smoother overall after everything was properly tensioned.

Thanks for the helpful insights about the belt tensioner repair. After getting both pulleys replaced, I noticed a significant improvement in overall engine performance. The car definitely runs smoother and quieter now, especially during cold starts. Fuel consumption has slightly improved, probably because the belt system is operating at optimal tension now. The engine noise completely disappeared after fixing the worn tensioner pulley and idler pulley. The repair cost was worth every euro considering the peace of mind it brought. My mechanic mentioned the timing belt should be inspected at the next service interval, but for now, the serpentine belt system is working perfectly. The inconsistent tension issues are completely resolved. Looking back, those cold start squeals were a clear warning sign that the belt tensioner was failing. For anyone else facing similar symptoms, getting both pulleys replaced together is definitely the way to go. The entire belt drive system needs to work in harmony, and fixing just one component often leads to problems with the others later on.