f-150guy

2008 f-150, 5.4 problem just started. when stuck in traffic so idling rpm drop to 400 and engine sounds like it going to throw a rod, very rough. I give it gas and it goes away. This has happen about 6 times now when idling or backing up slow. Last time I was sitting at the drive through window when it did it again. No codes or fix it wrench lighting up. Please help if you can, I am thinking coils or MAP????

bama man

Sounds like a camshaft position sensor. When it stops functioning properly, timing will slightly be off at idle and can cause these problems.

lewissa81

I think Bama man is onto something being up with the timing.
Research the cam phaser issue. There are plenty of articles and videos. See if they match.