Ford Repair: 97 Ford Explorer XLT - Knocking when warmed up., chain tensioner, experienced service

Question
My engine has started to knock when it is warmed up. I don't notice it when I am driving but can feel it in the petal and I can hear a muffled knock when I am stopped. When I turn my engine off I hear a few additional knocks.  

Answer
Knocking noises from an engine are never a good sound.  The noise could be a connecting rod, which is a very expensive repair and could require replacing the engine.  A common noise heard from Explorer engines is usually described as a rattle, this is usually a bad timing chain tensioner.  I would recommend taking the vehicle to the dealer, and have an experienced service advisor or technician listen to the noise.  Dealers work on these vehicle daily and are less likely to misdiagnose your problem.

I hope this helps,
Dave