I took my truck to the dealer today and they kept it.The tech pulled the upper plenum and the lower intake runners are coated/lined with oil and carbon! The pcv valve is very oily too.He pulled a few plugs and they were oily and carboned too! He had to call the Ford tech line to get further instructions on what to do.He thinks a baffle in the valve cover might be defective,but won't be able to go any further until Monday.

 

hi, after my engine rebuild when all was clean i still got the rattle when under load at cruzin speed. it was always made worse when pullng hills with a caravan being towed but playing with the throttle i could keep the sound to a minimum.
the strangest thing is, when i converted to propane gas no more death rattle!
all the info about propane use tells me that it simply masks the sound and the problem is still there. so now i have stopped thinking about it and hope all is ok. bokker.

 

Dayum,finally got my truck back today! Here is what was done;
New MAF sensor
New IMRC actuator
New pcv valve and (2) hoses
New valve cover baffle
New spark plugs
New gaskets;upper and lower intake,valve covers
New fuel filter
De-carboned upper and lower intakes
De-carboned engine;rings,pistons,valves,etc. -(3) times
Oil change
Compression test
Cylinder leak down test
I only had to pay for the fuel filter and $15.00 of gas,due to it being empty when I brought it in there Saturday!
They test drove it and it pinged very slightly,only on hard acceleration upon first moving and very slightly upon upper speeds going over big hills,overpasses,etc.They compared it to another 07 with 18k miles on it,and an 06 with 25k miles on it,and mine was much more quieter,not even close to the others!
I'm satisfied,now,but will be monitoring it closely! Actually,it runs just as good or better then when it was new!

 

My 02 with 150k was doing the same thing, and here is what helped me. Go buy a can of mass airflow sensor cleaner, remove your mass airflow sensor (special tool bit to remove from sensor housing) from the housing and spray it really really good and reassemble. I believe it couldn't accurately read the amount of air entering the engine so therefore the air/fuel ratio was a little off causing pre ignition. It worked no more rattling valves on acceleration. That was bout 5k miles ago. Be sure only to use the cleaner I said before anything else can and prob will damage that expensive sensor

 

Forddude02, read my reply above yours as to what the problem was and the fix.