I have a 2001 4x4 F150 5.4 engine with 90,000 miles on it and it does the same thing at idle that all you guys are talking about. I have noticed something else though and I would like to know if anyone else has this problem. In Park, I can not put the tach on any RPM between idle and 2000 rpms. I try desperately to put the revs on 1500,,,,can't do it. Mine moves about a needle with at idle and after that it's 2000 or nothing. I'm thinking rough or noisy pot (tps). Do any of you have that problem?

 

My has somewhat of a vibration at idle. Its dont it since I bought it with 67,000 miles at it and right now Im about about 124,000 miles without any engine problems.
If there was a serious problem that was causing that vibration, something major would have broken by now. However, it fires right up every day and runs like a top, so Im not all that worried about it.
Octane

 

Are you able to hold the engine at 1500 rpms in park? I have the vibration at idle but I also can't hold the engine at any speed under 2000 rpms in park. The truck idles fine with a slight miss.

 

my 5.4 vibrates at 1mph only...at 2mph and 0mph it is OK. Problem has been there since delivery. Annoying as hell at every red light, and when parallel parking....damned thing shakes just before stopping.
FORD took it back, tested computer, changed driveshaft and couldnt fix it. We settled on a free 7yr warranty.
Good luck....would love to know if you find your problem.

 

huh
Ya, Ford is going to give me a new truck.

I changed the plugs this week end and it completely cleared up the idle problem.
I played with the throttle body and found the the butterfly was sticking on the housing.
I cleaned it up and lubed it and it all workd fine now.

Life is good.

 

Maybe it is a tranny problem, does your truck have a auto or manual? My 5.4 runs really smooth for the amount of kms it has, but I do notice when it goes through the warm-up process before it reaches normal operating temps there is a vibration (roughly between 800-900 rpms) then it goes away when it settles down to 600rpms. I have the 4R70W auto, not the best tranny but the vibration is normal according to ford(ya right!)

 

I have a 2000 f150 4.6 mine has 109,000 miles on it and had a miss or rough idle Idid every thing you all said and to no avail. Then I was told on this forum to try sea foam. you take the pcv hose off the pcv valve and suck up 1/3 of the can while the truck is running then cut the truck off and let sit for 15 min. run the truck (will get white smoke for about 20 min. thenthe job is done it did the job for me. (NAPA sells the seafoam) It cleared up my problem I don't know about if it would clear your problem up.

I don't know what BG44 is and or how you use it whether it is similare to sea foam or not.

What I beleve is happening is like the old days when you would pour tranny oil down the carb it gets into the valves and cylinder and cleans it up.

But whan all is said and done my miss or rough idle was gone.

Lance

 

oK...I will make number 3 to mention the IAC. I am surprised more people haven't said something about it since it is a well known problem, and an easy one to fix. The IAC, can cause all sorts of weird idle issues. it can be anything from idling slightly rough, to the surge problem...but all at IDLE. The IAC fails, it gets dirty, it just has problems. You can get a replacement from the dealer for about $85 or locate one at a local parts store for about $70. One way to find out if the IAC is the problem, is to remove it, spray it clean with carb cleaner, then see how the truck runs. If all work well then returns to acting up, replace the IAC, it is dying. If it works better and stays that way, then it was very dirty and will need to be replaced within about a year. It is very easy to replace. On the 5.4's, it is located at the BACK/TOP of the intake manifold. Remove the plastic covering that has the 5.4 printed on it, (3 bolts), then look behind the manifold by the firewall. You can see it there. 2 bolts and 1 wiring harness is all it has. For the 4.6 liter, it is on the TOP/BACK of the manifold. Remove same plastic cover, (4.6 on it), and there is it. Easier to get to than the 5.4.

Rugermagnum....did they do anything with the dash when working on your truck? Sounds like the gauge face or the needle is a little off and it is hitting in that area. easy to fix.

 

Billybob69 is right about the IAC valve. Clean it first with throttle body cleaner or carb cleaner but make sure to disconnect the neg. battery side because it will reset the computer of the truck. After you clean it, it should run and idle better. My symtom was a little different my idle was a little rough but my valve caused a howling noise from the air intake. After replacing the IAC valve the idle is smoother and the noise is gone. I also noticed a little increase in fuel milage but not a lot about a mile more per gallon is what i got on my weekend trip after replacing the valve early saturday morning.