Have a 2005 f-150 4x4 with 31,500 miles. Recently it started to tap very loud. The noise seems to be coming from the rear of the engine. Took it to the dealer and service writer origionally said it sounded like cam phasors but then looked up the VIN and found that the 2005 4.6 didn't have cam phasors (I'd already been told that by 88racing on this forum--thank you). They took valve covers off, inspected, and listened with stethoscope and said that they didn't feel anything was wrong with the valve train. They said the suspected the flex plate was cracked. Removed old flex plate (no cracks or broken welds etc) and replaced with a new one. Still tapping from cold start, when engine warm, and at every rpm level. Engine still runs fine but I know that with that kind of banging something's got to be wrong. Anyone have any ideas or suggestions before this thing puts me in the poor house? Thanks.

 

Did you notice any Sludge build up when they had The V.Cs off ?
Could Be Lash Adjusters,Flat Cam,Timing Chain Trencher Ect. Resonating thru the
Motor. Cant believe (yes i can) that the Ford House said there nothing wrong. Well Good Luck and Keep us posted on what you find.

 

They said all was clean when inspected. I've always used synthetic oil (5-20) and the darn thing only has 31,500 miles on it. This shouldn't be happening.

 

I have a 2003 with the 4.6 and had the similar noise only mine was at the front of the engine. I took it to 4 different shops and got 4 different answers. I kept telling them it sounded like a stuck lifter. Finally took the v.c. off and removed the front four lifters on the left bank and replaced. Noise gone. That was over 75k miles ago.

 

I know it sounds like its at the back but try removing the serp belt and and start it up. If the noise is gone then suspect one of the FEAD components. Also while its running remove/disconnect one injector wire at a time. If the noise dimminishes or goes away on a particular cyl you may have a rod bearing going. Have you had the intake manifold or sparkplugs out recently? Does it sound like first order crank speed or second order cam speed (half crank speed) A inexspensive stethescope should get you in the area of the noise. Try around the oil pan, cam covers, front cover etc.with the probe. Good luck

 

We found the problem last Friday. Finally pulled the engine and pulled #4 piston (determined by shorting injector). It was trashed. Took it to a local machine guy of some renown in in engine rebuilding and he said he sees it all the time with those engines. His theory is that the pistons themselves are poorly designed and have skirts that are too small and won't dissapate heat so piston swells and galls the wall.
This whole thing freaks me out on an engine with only 31,000 miles which got only normal use,synthetic oil, and good preventive service. I'm gonna replace with a Jasper and hope for the best....at least I'll have a warranty for the next 3 years.
No more Fords for me although the rest of them are probably just as bad.

 

No more Fords, even though they don't make the 4.6 any more?

 

Well I can promise you I have seen thousands more modulars disassembled than your machine guy and the pistons are not a problem. You may have a siamese bore that is generating a hot spot, micro welding caused from debris at the top piston land, broken ring, top land broken from preignition or an over heat condition at one time that started piston scuffing. I would like to see a picture of the piston and bore that is damaged. I would almost bet that the rod is very slightly bent from a hydrolock(especially since your truck must sit a lot with such low miles) and that bend will push/twist the piston to one side of the bore and cause scuffing. Check the rod straightness. These engines have won awards for not only design but durability and efficiency and better yet they are real life proven for durability. Your Jasper engine will perform well for you. good luck.

 

Thanks for the reply Dynotech! I would like to send you a pic of piston & bore but installer put back in the core that was returned to Jasper.
Your assessment of the problem makes a lot of sense in that the truck does sit a lot (most of my driving is done in a little diesel that gets close to 50mpg as opposed to 18), but when I need my truck , I NEED it. Funny, but I origionally bought the truck with that engine because it had a reputation for being "bulletproof" as you've indicated. Guess I'll have to make a point of driving it at least once a week to avoid hydrolock in the future.
Jasper running great at this point.

 

I have a 2003 f150 with a 4.6 Windsor and I had a blown head gasket and I am in the process of reassembling the engine. I also had a valve job done on both heads and now I am wondering how do i set the timing now that the heads and the cams have been removed and re installed after the valve job. I am aware of the timing process how do I know if the cams/valves are in the right position?

 

There is a how to for that here somewhere.. Little searching and here it is.. Follow the instructions precisely you only get 1 shot at getting it right Next time start a thread.
https://www.f150online.com/forums/ar...r-engines.html

 

200k on my 4.6L, still running strong.