Is there a timing mark on the engine? And where is it? on 2000 Ford Explorer

The truck has a bad mist. The garage says it needs a timing chain.

2 answers 2 comments
explain bad mist please
the engine idles up and down.
do u have any engine codes?
Hope this helps you http://technoanswers.blogspot.com/2011/09/timing-chain-marks-for-1998-ford.html