It started with a bad bearing noise which I decided came from the timing belt tensioner. Replaced the tensioner and adjusted the belt tension to very tight, as it had been with the prior unit. Grinding noise went away but now I have like a moan at very low speed. I can idle below or run above that "moan" speed and all seems well. My Seloc manual does not tell me how to set timing belt tension. Could I have it wrong and could that cause my noise?