I would look for loose or disconnected vacuum hoses, although surprised no
codes are being thrown.

Chris Bowne
Stonington, CT

Not sure about the 3.0 but when the 4.6 pings it's usually the MAF (mass
air flow sensor).  Does the 3.0 have injection and a MAF?  Easy fix.
Involves cleaning.

Use a higher octane.

try a professional injection cleaning (motorvac). typically weve seen
injector nozzle buildup cause a pinging condition as well as carbon
buildup up on valve stems and piston tops. motorvac will do away with
both.

your egr valve is probably not working.  slightly stuck open can cause rough
idle and no egr opening under load can cause pinging.  that car uses
ignition timing and egr to eliminate predetionation.  manually open the egr
valve with the motor under load and see if the ping stops.  the system has a
dpfe (egr position) sensor, egr solenoid, and egr valve.  if any bad should
set a code and check engine light but some times things don't work as they
should.  that motor is made to run with no additional benifit from any
higher that 87 octane.  If higher octane apears to fix the problem you
probably have deposit buildup on top of the pistons wich a good combustion
cleaner (not anything you add to the fuel tank, any good cleaner is not good
to set in the fuel system for days)can take car of.