Failing Belt Tensioner Causing Noisy Engine Problems

Based on some experience with belt tensioner issues, I dealt with a very similar problem on my 2005 Grand Cherokee. The symptoms match exactly what you described, increased engine noise and erratic belt movement. The issue was definitely the belt tensioner assembly. My mechanic found the tensioner pulley was severely worn, affecting the entire belt drive system. Besides the tensioner, they also recommended replacing the idler pulley since it showed signs of wear. The timing belt was still in good condition, so that didnt need replacement. The repair involved: New belt tensioner assembly, New idler pulley, Belt realignment, Full system check Total cost was 455 Euro and the repair resolved both the noise and belt movement issues. Engine performance returned to normal immediately. Before suggesting specific solutions for your case, could you provide: Current mileage, When you first noticed the noise, Any other symptoms like vibrations, Whether youve had any previous belt system repairs This would help determine if your situation needs similar treatment or might require additional work.

Last service was at 5000 KM and the belt squeal started shortly after. The automobile maintenance history is clean with no previous belt drive repairs. Your solution sounds very similar to what Im experiencing. My serpentine belt symptoms match exactly what you described. Though my idler pulley seems to be in good condition, the mechanic might need to check it during the repair. The current estimate Ive received is 380 Euro for just the tensioner replacement. Considering the clear similarities in symptoms, I might follow your repair path and have them inspect the entire belt system.

Thanks for the follow-up. Since we have the same model series, I can confirm the repair approach worked long-term for me. The belt drive system has been running smoothly for over 50k km now with no belt squeal or tensioner issues. One thing I learned from my experience, even if the idler pulley looks fine, having it inspected during the tensioner replacement is crucial for automobile maintenance. The labor cost difference is minimal since they're already working in that area. In my case, the wear wasn't obvious until the mechanic did a thorough check. 380 Euro sounds reasonable for the tensioner work. My higher cost included the idler pulley replacement. The entire belt drive system really needs to work as a unit, if one component is failing, it often affects others. Since your belt squeal started soon after service, have them verify the belt tension settings too. Sometimes incorrect tension after maintenance can accelerate wear on the belt tensioner components. Would definitely recommend having them do a complete belt drive system inspection while they're replacing the tensioner. Better to catch any potential issues now rather than having to go back for additional repairs later.

The timing lines up perfectly with my last service, this is really helpful feedback. I feel much more confident about moving forward with the repairs now. The similar model and symptoms make your experience particularly relevant. Given my belt squeal started right after the service, I will definitely have them check the tension settings. I just called the shop to schedule the work and requested a full belt drive system inspection along with the tensioner replacement. They agreed to check the idler pulley condition while they are in there, which makes sense to avoid future issues. The estimate increased to 450 Euro with the additional inspection work, but that seems worth it for the peace of mind. Better to handle everything at once rather than risk more belt drive problems down the road. Will schedule the repair for next week and hope for the same long-term success you experienced.