I have a 02' f-250 with the 5.4 V-8 and 31K miles. The other morning when I started her up, I noticed that while in Park, I revved her up to 1800 RPM and noticed a "Rapping or Rattling" sound coming from the engine compartment. I don't hear it when she's in Drive and moving along. Anyone else encounter this or hear what the problem could be ? I'm scheduled to bring her in for the 30 K check-up but I would just like to possibly have som good intel before I go to the dealership.

Thanks, PM

 

Was it cold, sounds like it...it was probably the forged pistons that haven't yet expanded in their bores, they rattle alot until they get warm and circular...You know they are egg shapped when cold...

There is alot of talk about the piston knock on the 150 threads..

Good Luck..

 

Thanks for the reply and sorry I took so long to respond. I brought it in to the dealer and they showed me a technical bulletin that states that the noises are due to "Light load operating conditions and the normal bore clearances present in a cold engine". States that this noise has no affect on performance or long term durability. Oh, and speaking of performance, I recently tried a fuel additive by Lucas Oil. I noticed an increase in acceleration performance and 1-2 MPG improvement. A friend turned me onto it and he swears by it. Only about $7.00/ bottle and it treats 100 gallons of gas/ diesel fuel !