I have multiple issues with my truck. First is the cam phaser which knock at warm idle. I also have a rough idle. I changed all the plugs because before I had a missfire that would move the steering wheel back and forth while idling. Now after the change you can steel feel a vibration when it is idling. Can the phasers be the cause of this vibration or rough idling? Also when I let off the throttle there is a awful ratching noise that you can hear for 2 seconds before it goes back to idle. Are those the chain tensionors? Also if I just replace the phasers will the noise come back? I heard it's from oil pressure. If so, wouldn't that mean that the oil pump is bad? Need some advice here on what I should do.

 

Yes, replace everything, phasers, VCT solenoids, guides, tensioners, oil pump, gaskets. Inspect your cam journals for scoring.

https://www.f150forum.com/f4/final-r...-sound-141266/

 

I was in the exact same situation as you last month. Folks on this board told me not to cut corners and replace both phasers and all chain components. I didn't listen thinking that I'd chance my luck and not replace the one phaser (and VCT) that wasn't noisy and save $300. Well, it didn't work, I wound up having to go back in and swap out the only parts I didn't replace a week later as it was still getting cam codes and running like crap.

Do yourself a favor and get two OEM phasers, decent chain/tensioner set (I used Cloyes) and an oil pump too or you will probably also regret it. Took me an extra 4 hours to go back in and fix it right the second time but now I'm confident that it's going to run for a long time and it idles smoothly again, the power is back and noises are gone.

 

Did you have the problem diagnosed prior to changing plugs or did you just change them and assume a problem?

I ask because a weak coil will take out a plug. This means you may change plugs but have only affected the symptom and not the problem. The true problem was the coil and the plug was just a victim of that problem.

As for the timing work, if you are going to do it, do it all. Do not open up the can of worms and not change everything in there.

In general the phasers fail due to a lose of oil pressure down stream from a fail seal in the chain tensioners. Again, changing just the phasers is treating the symptom and not the cause. Far too many shops do this only to have to open it up later when the phasers quickly fail again.

 

Would the phasers cause a vibrating idle? Possibly because the timing is off?

 

Bump