Ok, here's the scoop. I've got a '06 xlt with a 5.4 3V and several months ago it started acting up. At first it was just when in reverse then it was anytime i was operating under low rpms like in a parking lot or such. It would miss/knock/shudder. Kinda sounded like a bad running diesel. It also kinda rattled during acceleration up to 1500 rpms or so. It would only do this after being warmed up. When cold it was fine but after getting warmed up it got to the point that it would act horrible. I replaced the timimg chains, tensioners and guides thinking that was the issue and it was not. After reading a bit on the cam phaser and VCT issues that folks have had with this engine I unplugged the VCT solenoids and low and behold the noise is gone, the missing/bucking/diesel sound is gone and there is little to no noticible loss in performance. Now I don't want to drive it like this forever but will until I determine the cause. I was wondering if anyone can give me any clear insight into what is the culprit. Is the solenoid or the phasers?
Last edited by heatseaker1; 12-18-2012 at 09:03 AM.
Since you have the easier valve covers to do this on, I would suggest pulling out your VCT's just to inspect and possibly eliminate them from the equation.
You should be able to use this step by step and get to the VCT's with ease. Unless, however, your valve cover does not have the easy to remove seal around the VCT's.
I replaced the VCT's on my 08 (which is not as easy as the earlier years as you have to remove the entire valve cover to get to them). Once the VCT was out, I noticed damaged screens on it. That narrowed it down pretty quickly for me.
Also, if you do end up replacing them, as unlikely as it sounds you should call up your local stealership for the part. It might actually be cheaper. At least it was in my case. By $120.
I have replaced several solenoids for noise and running concerns . Not just Ford products . The screens seem to be the main issue . They plug and or come apart . Make sure you use the correct weight oil also .