2006 Mercury Mariner V6 engine noise
 

Its a 2006. owned it since 2007. has 107,000 miles.
No previous problems, was driving yesterday, came to a stop light, stopped. engine shook and shut off. placed it in park, restarted it. runs rough. LOTS of valve train noise. slow throttle response.
Ran the codes. has P0340 and a P2198 code. The P0340 code is the cam position sensor. i Replaced it. no change. The P2198 code is i read is a lean fuel code. (not the problem)
Any and all advice will be greatly appreciated. Thanks

I had a similar problem. Started the vehicle and it sounded like something was broken inside the valve cover and was being thrown about. After listening to it more closely I could hear that is more of a misfire instead of something that was broken. Very loud. Engine ran rough and had a hesitation when stepping on the gas pedal and the only code it was returning was P0340.

Turned out that my timing chain jumped due to a chain tensionor that was failing. Replaced the chains and tensionsors and all is well.