load knock

[F7snopro]

I have an 05 5.4 EB with 74k. I was just told that the knock Im hearing is piston slap. Has this been a problem for anyone else? I was also told that this will only get worse then the motor will fail. I was also told the motor needs to be replaced.

This has gotten worse this past year and my mpg has dropped 2 to 3 miles per gallon. Additionally, the motor has lost power while towing.

Any feedback and info would be great.

 

[Stoned06]

Piston slap has been known to show up on the 2 valve 5.4 engines, not sure about the 3 valve engines. Just curious, but have you tried a higher grade fuel just to rule out bad octane gas causing detonation?

 

[F7snopro]

loud knock

Yes I have. The truck does seem to run better, but the knocking is just as loud. Im bring truck to dealer Friday. Im trying to see if this is a common problem. Thanks for the info.