VW Transporter Belt Tensioner Failure and Repair Tips

I had a similar issue with my 2008 VW Caddy. As someone with moderate car repair experience, belt squeal and irregular belt movement are often signs of tensioner problems. My serpentine belt started making similar noises and showed irregular movement patterns. After noticing the engine performance was getting worse, I took it to my regular workshop where they diagnosed a faulty belt tensioner assembly. The repair involved: Complete tensioner replacement, New serpentine belt installation, System alignment check Total cost came to 455€ including parts and labor. The repair took about 3 hours. Since then, the engine noise disappeared completely and the belt runs smoothly again. To provide more specific advice for your case, could you share: Current mileage on your Transporter, Whether you hear any specific timing belt related sounds, If the issue is constant or only occurs during cold starts, When you last had the serpentine belt replaced These details would help determine if your issue matches what I experienced and whether you might need similar repairs.

Last service was done at 81000km and current mileage is 83175km. The timing belt related sounds are most noticeable when the engine is cold, particularly during startup. It makes a distinct squealing noise that seems to lessen after the engine warms up, but never completely goes away. The serpentine belt was actually replaced during the last service, but the idler pulley and tensioner were not touched. The belt has also started to show signs of uneven wear on one edge, which makes me think the belt drive system might be misaligned. Based on your experience, this does sound similar to what you encountered. Will get it checked soon since I dont want a complete belt failure while driving.

Thanks for those details, yes, your symptoms match exactly what I experienced with my Caddy. The cold start belt squeal and uneven wear patterns are classic signs of a failing tensioner, just like what happened in my case. Since your serpentine belt is relatively new but showing uneven wear, this strongly suggests the tensioner is not maintaining proper belt drive alignment. When my tensioner started failing, it also caused similar edge wear on a nearly new belt. For reference, my Caddy had about 85000km when the tensioner failed. The timing belt tensioner assembly was original, which likely contributed to its failure. Given your mileage is similar, you might be facing the same situation. A quick tip from my experience: While replacing the tensioner, have them check the water pump and other belt-driven components. When my tensioner was replaced, we discovered the water pump bearing was starting to wear. Replacing both saved me from another repair visit shortly after. The complete job including the water pump ended up costing 650€, but prevented potential engine performance issues down the line. The peace of mind was worth the extra cost.

Thank you for explaining your similar experience. The cold start symptoms and the uneven belt wear you described definitely match what I am seeing with my Transporter. Your repair costs and timeline are helpful to know for budgeting purposes. Since my vehicle is showing the exact same signs at a similar mileage point, I will plan for both the tensioner replacement and water pump inspection when I take it in. Better to address potential issues now rather than risk further engine performance problems or complete belt failure. I will schedule the automobile maintenance appointment this week to get the belt tensioner replaced and have them thoroughly check the entire belt drive system while they are working on it. The squealing engine noise and irregular belt movement have me concerned enough not to delay the repair any longer. The total repair cost of 650€ including the water pump seems reasonable considering the work involved. Appreciate you sharing the details of your experience, it has helped confirm my suspicions about the failing tensioner and given me a clear idea of what to expect during the repair.