WELCOME, and sorry to hear about your issue. I had an issue last time I did my timing belt due to a bolt that snapped and I had to drill out and use a helicoil but that was on the AC/alt belt tensioner. Where are you getting the timing belt tensioner assuming you are talking about the hydraulic tensioner. That is not cheap to replace every time either, along with all that has to be removed just to work on it. I would not know what would be causing it other than possibly there is something wrong with the belt itself? Did you change the pullies also?
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