I'm lost for words I have a 03 4.0l sohc ranger just recently rebuilt top end new vales timing chains etc. Well truck has been running really good but today after a week of driving it for the first time I was coming back from the store and truck just shut off. It started making a rattle sound kind of like when a chain is loose but a tight rattle sound and it started to missfire and idle rough I drove it home but it would not pick up speed. My quess was the top front timing chain because the sound is coming from the front and sounds like it's right under the valve cover. Well I took off the cover and top chain seems tight and guides are still new. What could it be?? Because last time it made this sound the chain was loose and guides were broke but this time them look good could it be the tensioner witch I hope. But I really need to know before I get to deep into it because I just pulled this engine and fixed it and I can't afford that anymore please help