I put a new timing chain, guides, and tensioner on my 1994 Nissan pickup with a KA24 and it sounded good the first time I drove it him and it's been about 5 months since replaced but not long after I replaced it the noise was there and I heard the alternator bearings can go out and sound close to timing chain do I assumed it was that waiting on replacing kept driving the truck. Last week replaced the alternator no change. So I room off the valve cover and the tensioner side was tight but other side wasn't. I turned the motor over a couple times and then both sides were tight and I did it again and then it was loose again any ideas?