rottencommie

I have an 09 5.4 with about 136k miles on it. I bought it with 130k, and a month or two later I noticed a loud clacking noise that I assumed was a u-joint or something. Not sure if the noise was there the whole time or if it developed after I bought it. The more I tried to pinpoint it, the more I became convinced that it was the phasers. I even had a mechanic who mostly works on F150s drive it and he thought it was phasers.

Today, just for the hell of it, I unplugged both VCT solenoids and drove around for a couple minutes (while the truck was already hot) and I couldn't reproduce the noise. I plugged them back in, easily reproduced the noise, then unplugged them again and I couldn't hear it. What has me confused, though, is that the truck doesn't seem to have any noticeable issue with timing - runs fine, idles fine, doesn't act erratic. It didn't seem to run any different with the solenoids unplugged, although to be fair, I was just on 25mph residential streets for less than 5 minutes.

I was excited when I thought I had figured out that it's just solenoids, but now I'm starting to second guess why the truck would run fine and make noise, but seemingly run fine and make no noise with the solenoids unplugged. Anyone have any ideas?

VTX1800N1

Your phasers are bad. With the solenoid unplugged, they remain physically locked in the full advanced position. You can drive it like this, but fuel economy and emissions will suffer. Once you connect the solenoid and the computer tries to retard the cam timing, you are hearing the noise because the phasers are no longer locked.

rottencommie

Well, dang. I guess I'll start saving some money for a phaser job.