I have this rattle somewhere near the firewall .at first i thought it was in the ductwork of the heating system,but im almost ruling that out because it still rattles when everthing is turned off. It rattles more when i'm not accellerating.then when i speed up it quits rattling. its not mettalic.is more plastic sounding. its hard to tell whether its in the ducts or something ratting on the body when i accellerate. I have a 98 ford windstar 3.8Litre engine. any ideas or anyone else ever had this problem please let me know. thanks. winter is coming up and sounds always get worse in the cold weather.

 

Sounds like the speedometer cable. I believe that the 1998 model still used a speedo cable.

 

Is that a hard job to install for a novice mechanic?

 

Not sure. Probably the hardest thing about it will be the room available to get your paws in where they need to be and contorting like a pretzel.