I have read several threads that many others are having problems with a knocking sound in their engine that makes their truck sound like a diesel. I have this same problem. I took my truck to the local Ford dealership where a tech told me they'd had a few vehicles in with low oil pressure which was causing noise from the cam phasers. He thought this was my problem. When they told me the repair would cost $2000 I decided to do it myself. I checked the oil pressure and had 20 psi. The dealership said it should be 25psi, I've read online a minimum of 20. I'm not sure if I really do need to replace the oil pump. I finally got the engine tore apart a few minutes ago. I found metal shavings in the oil pan. Got me a little worried. But when the front cover came off I found a bad hydraulic chain tensioner, the timing chain was extremely loose, and had been beating the cover. That's where the metal came from and I think that's where all the noise was coming from as well. I believe I'm going to replace the tensioner and put it back together without replacing the oild pump. It was alot of work to get this far. Does anyone think I'm making a mistake by not replacing the pump? Considering I had 20 psi at idle with the engine hot.

 

I've read That when that hydraulic tensioner fails it looses oil pressure.
Send this guy a pm. He's a ford shop tech and he might answer your questions..
https://www.f150online.com/forums/me...-bigbronc.html

 

I too had the "cam phaser" noise and the deal 'fixed' it and granted me an After Warranty Adjustment and it only cost me $300 +tax.
That was at 40k miles on the truck (2004 truck work performed in 2009). Now with 47k miles I got the sound back. At start up it sounds just like a diesel and slowly quiets down until put under a load. Just accelerating on flat road causes the noise and mainly from the passenger side.
Any idea's?
Is this the same issue you are having?
What next? ? ? ? ?

 

Dealers love noisy cam phasers. $$$

 

Got it fixed, 4 mechanics in one day and two had the same diagnosis; exhaust manifold leak! Got the passenger side replaced and the diesel truck sound is gone. I love Ford but I hate Ford at the same time, what's with the crap they've put out on the road the last 10-12 years. Hell my first F-100 Ranger XLT was a 72 (when they were still a full size truck) and it ran like a top with tons of miles and very little trouble. How I wish I still had that one....