My truck (08 F150 5.4L 3V) has been making the wonderful ticking sound for a while, but I was suspecting it was an exhaust leak from the passenger side exhaust manifold. I suspected this even more after my other truck (10 Raptor 5.4L) had the same thing replaced under warranty. However, I am now having more symptoms.

On a cold start, the engine used to sound normal. After driving for a while and getting the engine hot, anything at low speed, specifically anything from a dead stop and being very light and short on the gas pedal, it sounded like marbles shot into a tin can. It for some reason sounded worse when put into reverse.

As of lately, the engine starts to sound like a muffled version of marbles on a cold start. Once hot, the sound is absolutely terrible. The engine ran very rough on me the other day, and I thought it was going to die in the middle of downtown. It sounded like it was running on 3 cylinders and about to stall. Giving it a little gas did nothing to the sound or the shake. The tach went higher (from roughly 300 to 1000), but the sound and shake never changed. The truck had no power for about 5 seconds, and then went back to normal.
At highway speeds, I have no issue what so ever. Only very low acceleration will i make the awful noise. I also have a fairly rough idle. If I put it into neutral, it does make it better, but I assume it is just from taking the load off the engine.

History on the truck now, it has about 190,000kms (120K miles). I have replaced the VCT sensor on the driver side after it failed roughly 60K kms ago. I however, have not replaced spark plugs yet (I know, i know), but otherwise have kept up on the maintenance with this truck.

So could this be the dreaded cam phasers? A transmission issue? Or is the noise something more simple like a timing chain slap from a broken tensioner? I have not had a check engine light come on for this yet so any help would be greatly appreciated before I start tearing into this.

 

Okay, after a little more diagnosing, I am leaning towards a transmission/t-case problem. The noise seems to go away or at least be much quitter when I take it out of gear. SO, neutral or park, engine revving slightly, the noise is almost non existent. As soon as I do the same in forward or reverse, the noise comes back extremely loud, and affects the engine.

Any ideas?