2006 f150 4x4 5.4- 212k miles. Sorry it's long but I'd like to explain my process. Truck was running great then out of the blue, it started occasionally running rough when you stopped at a light or stop sign.

It only did it occasionally and only after fully warmed up - never did it cold. The problem was a rough idle, some stalling, and noticeable clatter noise. There was usually no CEL & no codes and- it would clear up if you turned the engine off then restarted. The problem would recurr and would throw a light if you kept pushing truck. It was much worse and more frequent during towing. When it threw codes, they were related to cam timing and misfires. When it wasn't "doing it", the truck sounded and ran fine.

Read all about VCT solenoids, Phasers, oils, sludge, oil leaks/low pressure etc. and decided to try easy stuff 1st- several oil changes w/ correct motorcraft filters, and tried 5w-20 as well as 15-40 diesel oils. The condition improved but still did it on occasion and eventually got even worse.

Then a revelation- after reading hundreds of posts - I tried unplugging both VCT solenoids and the truck ran and idled flawlessly- cold and hot! No noises, no stumbles, no stalls- no roughness. It got worse gas mileage, and threw a CEL- but other than that, the truck ran perfect. So I figured- VCT solenoids were getting stuck and needed to be replaced.

Before replacing with new FORD OEM solenoids, I decided to flush clean the oil system with Marvel Mistery Oil (MMO). I drained one quart of oil and replaced it with 1 quart of MMO. I also re-plugged in the (old) VCT solenoids just to circulate the MMO through those ports. At first the truck, acted like it had (with the occasional roughness at a stop light) but slowly- it got better and even went away completely! I was shocked and amazed! The addition of the MMO completely fixed the problem. I even towed with it and it NEVER acted up!

A few weeks later, a freind of mine asked me to borrow the truck for long trip and I lent it to him. When he returned, he told me the stumbling was back. SO- I decided to bite the bullet and change the oil and put in the new solenoids this past weekend.

Well- the truck doesn't stumble but it sounds HORRIBLE! With the new solenoids, I get the clatter almost all the time- hot and cold??? It doesn't stumble or run rough but the clatter makes the truck sound like a jalopy!

WTF??? I don't understand how brand new Ford OEM solenoids could so drastically change the valve train noise???

Any Ideas?

 

Following. I have these same minor problems but they are not bad enough to do anything yet. No stall or dying just rough idle and clanking noise only after warm.

 

with 212K miles on her I would bet you need some timing work.

 

What oil , weight, and filter did you use after changing the VCT?

 

same as before rotella T ful Syn 5w40- motorcraft oil filter.

 

I don't disagree but why the major change in clatter simply with vct solenoid change? If it were chain or tensioner noise- why and how would the solenoids effect that?

 

Who knows...willing to bet your guides are going along with the tensioners

 

Maybe the gummed up solenoids were hurting the timing components and they finally decided to start giving out? (convenient as it may sound)

 

it should be noted that the old solenoids I took out were clean as a whistle with all screens intact.

 

When you unplug the solenoid I believe this prevents the phaser from coming out of the locking pin.

The new version of the solenoids have vanes that act like check valves to prevent oil from back flowing from the phaser during operation. Not sure why this would have made your situation worst could be unrelated.

IMO the next step is to pull the front cover and do the timing and phasers if you plan on keeping this engine. You might want to put a real oil pressure gauge on and see what you have. If I remember correctly you need at least 25psi at hot idle or you are going to have issues.

I would also run the engine and watch the main pulley to make sure it's not moving in and out. I have read these engines can loose a thrust bearing resulting in low oil pressure. Remember the dash gauge is not real anything over 5psi I think reads half scale.

I did the timing job with non ford parts and had issues which resulted in me doing it again after 5k miles with all ford parts. I think I have about 35k since then issue free.

The phaser system has had its flaws but the phasers and solenoids have been updated to address these. If the engine has oil pressure issues because of worn bearings new timing and phasers will not fix it.