I have a 1994 E320 station wagon. The tensioner pulley flew off the motor. I replaced the pulley with a new one. The old pulley was worn out. I have an old style tensioner with an adjustable tensioner bolt on top. Everything looks good with the serpentine belt line up. However, the belt was not able to tighten up like it should leaving a flapping belt when running the motor. I already had bought a new tensioner adjustment rod earlier and it runs fine tighten wise until the tensioner pulley flew off the engine. Even though, the motor runs fine and charging slowly, I need to know if it is the belt tensioner itself is worn out, needs new shocks absorber, or can I replace the belt tensioner with an automatic belt tensioner which I prefer to have without the hassle of using the belt tensioner adjustable rod. Will an old style belt tensioner with adjustable rod replace with an automatic belt tensioner without the adjustable rod work on this particular model? If I have to replace the tensioner, which I never have done this before, what do I need to do first to get to it? Do I have to remove the water pump and others before I remove the tensioner? I would appreciate step by step instruments to do this as I am still a newbie in this area. Any helpful advice is greatly appreciated. Thank you for your time reading this issue.