...all of a sudden....The wife was backing out of a parking space and all of a sudden it started sounding like big diesel engine.....Any ideas of where to start with this problem....I can do things mechanically but am pretty ignorant to engines beyond the very basics....initial thoughts are a valve or a lifter....I don't believe we are getting smoke out of the exhaust if that helps.

 

Try to tell if the noise is coming from the front of the engine - Early 3.9 MPI motors suffered from a'chain slap' noise from the timing chain, especially aftersome wear. The timing chains get some stretch in them, and due to harmonicsinherent to odd-fire V6's, start making a slap/knock/rattle. The Mopar fix was a new timing set revised w/a chain tensioner. If this is your prob. & you do a timing chain/gear set, be sure to get the new tensioner - important.

 

Exactly whatbelowrdr said.
For a list of the parts you need (including part #'s) and the steps to do the repair, visit this webpage.

 

mine sound like a diesel too. my timimg chain is worn bad and it has a bad lifter sound.


try putting a litre of tranny fluid in it and that should take away the lifter noise