So I just bought my first f150 a couple days ago. During the test drive I heard what appeared to be a diesel sound. I asked the dealer if he had it checked out and he said yes. I expressed concern about the cam phasers he informed me he thought the same thing when he took it to the mechanic but the mechanic said its not a phaser and its just a normal 5.4 sound.

I went over the truck with a stethoscope and it sounds like the its coming from the passenger side valve cover area. Only symptom (that I can tell) is the diesel sound. no lack of power. And it does this when its cold and hot. just on idle. Ideas? things I should check before jumping into a phaser job?

Thanks!

 

https://www.f150online.com/forums/v8...eshooting.html

 

It doesn't miss tho. And its only noticeable during idle And it sounds the exactly the same cold as it does hot. could it be just the beginning or a phaser going out?

 

Don't know what year, but a recent 2000 5.4 I worked on had the oil port on one side blocked by some errant RTV, pretty good knock from the lifters on that side.

 

Oh im sorry. its a 2005 Screw 5.4ltr. 143K miles.

Catmandu1999 Mine only happens at idle rpms. I will try and get a video this weekend of it and post.

 

Perchance, did the mechanic:

- observe /log the VCT PID's as live data?

- temporarily unplug the VCT solenoids - one at a time - to see if the noise stopped? (you can try this too)

-pull the existing VCT solenoids and inspect them fer blockage/missing screens, etc?

-try a pair of New-revision VCT solenoids? Part # = 8L3Z-8M280-B

-pull any codes?

-measure oil pressure @ idle? ( low oil pressure will affect chain tensioners )

... just thinkin' out loud ...

 

I wouldn't have bought if it was making a diesel sound, those can sometimes cost a hell of a lot to fix.