Hello, I make it a habit to replace critical bits like timing belts on cars with unknown to me histories. The question is should I also replace the hydraulic belt tensioner while I'm at it? I don't want to introduce any issues unnecessarily by futzing with it, but by the same token I don't want my new timing belt to skip because the tensioner was iffy. Or maybe the tensioners are basically indestructible? Km's unknown (battery is out ATM) oil on dipstick looks very clean. Opinions appreciated.