Knocking/shaking idle
 

So after a decent drive when I get to a redlight/stopsign/etc the truck will idle rough and shake but giving it a little bit of gas (1k RPM) seems to smooth it out however it doesn't throw any codes or the CEL. The truck is a 2008 F150 with the 5.4 and 90k miles.

I've searched quite a bit on this issue and I can't seem to find any real fixes other than swap parts out until something works and I've heard everything from filters to cam phasers or low oil pressure (I will be taking it to the mechanic to check the oil pressure)

so far I've:
Replaced the air and fuel filters
Changed the oil and oil filter (synthetic and oem filter)
cleaned the MAF and cleaned the throttle body

also is the 2008 equipped with an IAC Valve because I've read that it wasn't and I can't seem to find the IAC if it is.

Mine did this last week and for a few days and then a few days later when I hit 45mph or higher it starting shaking really bad and did throw a CEL. It turned out to be a misfire for me which was a result of a bad COP. At about 90k I had to change my plugs from misfires and the truck now has 97k on it so it was fairly easy to track it down. I would start with your plugs the 100k mark is not always correct it all depends on how you use the truck. I started having problems at about 82k with misfires and it got worse until I finally changed it but it never threw a code so I was not sure what the cause was.

Need a scanner that will read live data, it'll show you what cylinder(s) are having problems.

No, the '08 is equipped with electronic throttle. A motor built into the throttle body controls the position of the throttle plate. It's controlled by the ECM. The accelerator has no mechanical connection to the throttle body.

Good point I did not mention that. When my plugs were replaced they did a live data read out to show that I was having misfires on 3, 7, and 8 cylinders even with no codes being thrown. 8 needed a new COP at that moment while 3 was what I replaced last week. I guess 7 may go here soon on me but I can wait until it happens.

This is a more or less just when I slow down off of a highway and end up at a stop light the thing shakes like hell but on the road I've noticed next to nothing shaking wise.
I'll probably borrow one this week and testto find out
thank you, I feel slightly less stupid not being able to find it after digging around for it an hour :-X04

Mine started out the same way but the live data read out will tell you whats going.

the issue seemed to have went away for a few days until today it was doing it at a toll booth, I tried scanning it but when I rented the scanner I wasn't able to induce the problem :-arrgh.

I have spark plugs and the throttle body gasket in the mail so hopefully next week I'll do a total TB rehab and then change plugs(borrowed a lisle tool). For now I'm going to run some injector cleaner through it to help loosen up the plugs and it couldn't hurt.

ok well the poopoo has made contact with the fan...

This morning I went to leave for work and the truck was missing I put it in gear and it stalled out halfway out of my driveway I restarted it and it was really missing with the CEL on so I shut it off put it in neutral and pushed it back and crammed my tools into another car.

when I got home I let it idle so I can listen to it and it smoothed out but I still have a CEL tomorrow I'm going to pick up a scanner and a few coils and see if I can get the extractor off a buddy because my plugs came in.

I will be updating as I go because this is a very common problem it seems (3 threads about it on the front page) so I will keep everyone updated with a solution

Sounds good man I hope all goes well for you. If you run into a problem hit us up on weekends you can usually get a quick response.

Generally I know what I'm doing I just want to resolve this kink and get everything running smoothly you know and if I can help a few people with the same issue why not

I figured this morning the cam phaser went but can this even happen on the Post November of 07 trucks and the issues seemed to have resolved but I won't have any clue until I scan it tomorrow

I scanned it
codes
P0012 bank 2 vct
P0300 random misfire
P0302 cylinder 2 misfire
P0303 cylinder 3 misfire
P0304 cylinder 4 misfire
P2196 O2 sensor rich
Pending
P0010 vct connection

well now I'm stumped I can only think that the O2 sensor is bad

Update
I moved around and cleaned the coils and reset the ecu
started it up and it runs ok but still kinda off and I rescanned it and got the following pending codes
P0012
P0351
P2198

I did find one problem the connector for the coil was broken on one cylinder

so after doing a bit more work the truck is now driveable and sounds good but I still have a cel

down to two codes
P0340
P2198

how screwed am I?

I wonder if a dirty/contaminated fuel system/injectors might have something to do with it?

right now it's at the 3rd mechanic so I'm going to find out tomorrow what the verdict is, I personally believe it's a bad chain tensioner and my timing is off a tooth because I hope it's not a phaser