The other day I was backing our TT up the driveway.

The engine sounded almost like a diesel, and was running rough.

Our driveway is not flat, but it is darn close. The TT is a small lightweight one, so I was not pushing a lot of weight either.

My truck has also done this while just backing up the driveway to park in the garage.

If I rev it up it smooths out, but then may drop back down to run rough again or smooth out. Totally unpredictable.

No codes are thrown.

Is this more of the crappy cam phaser junk?

I run Motorcraft Oil/Oil filters and change at the recommended intervals.

any ideas?

 

My dad's buddy had the same problem on his 5.4 ...he said it was the cam phasers. Not sure if this could happen on a newer truck like yours. I would get a mechanic to check it out

 

I took it in the last time it happened. All they say is there are no codes and they are unable to reproduce it.

 

If it happens again and you have a smartphone on you, take a movie and bring it in.

 

How many miles on the truck, and have you had the injectors cleaned ever? I noticed that mine started to "chug" a bit at idle speeds, which was soon fixed by a tank of E-85 to clean out the injectors a bit. Subsequent tanks of regular have shown a marked improvement. Also, gas quality could very well be the culprit.

 

You might also have a bad O2 sensor. Rough idle sometimes points to a vacuum leak.

 

my 2010 5.4 at work has done the same thing from time to time. rev it up and it clears up, but at idle it will run rough and make some unhappy cam-phaser/timing chain sounds.

had it in for another reason and they said there were two pending codes for the cam phasers.

don't know anything more than that. see if you can get someone to read the pending codes and see if that turns up anything.

the video is a pretty good idea. when mine acted up it was very obvious. pop the hood and get a video of the engine knocking and bouncing about if you can.

 

The video idea is a good one. Thanks.