The rubber between the inner part of the tensioner that the rod pushes against and the outer part that has the idler and shock on it is what creates a springy tension, instead of a solid adjustment. It has a brand new idler pulley on it. I have replaced both idlers, the alternator, the fan bearing, and the water pump, including removing and re-installing the tensioner to get to the back water pump bolts. New radiator and other coolant hoses and a new expansion tank while the coolant was drained. Guess I'll order a new tensioner and see if that helps. Hell, I have already rebuilt or replaced nearly every mechanical part on this car except the engine itself and the rear end.