I have an 01 Lightning and having the same problem! I had the r/s head replaced last monday due to oil leaking out the back of it, every since its had this rough idle!! I just turned over 6,000 miles, so like alot of you, mine started about the same mileage. Dealer hooked all kind of equipment up and said everything checks out, that the idle"was a characteristic of the engine" WTF? It just irritates the hell out of me to be sitting at a red light and feeling the rpms bounce around. Mine seems to be worse in park, when in gear it's less noticable. For what its worth my wifes 2000 EB Expedition has the 5.4 and its alot worse than the Lightning, feels like it wants to stall at times and shakes pretty hard. As usuall the dealership's cant find anything wrong!

 

It has been a month now and the idle fix (see posts above for details) seems to be holding. The only roughness I've noted is a few seconds (3-4) when the air temp/humidity did a major shift between morning starts.

 

Not sure if my idle problem is the same as everyone elses. My problem is intermittent....sometimes when I stop at a red light, the engine idles very rough almost to the point of almost stalling (which it never has). Strangely the tach needle does not seem to indicate the roughness.

Well I had my truck in for an oil change and I mentioned the problem. The manager said a mechanic (who has a F150) had a similar problem and fixed it. I explained my problem to him and he confirmed that's what happened to him. No computer codes were recorded. He figured out the problem was with the EGR value and something about the fuel/air mixture was not being calculated correctly. Anyway, they replaced the part at no cost now I'll wait and see if that fixes my problem.

2001 F150 Supercrew
5.4
22,000 miles

 

I have 44k on my 99 4.6L. About twice a month when starting in the morning it will run/idle rough. Kinda feels like one injector is not squirting too good. If I rev it up a little the problem goes away, and it idles nice and quiet and smooth.

 

mine idles rough, been to the dealer 3 times with no luck..... 2000 f-150 4x4 5.4l xtracab 3.55

 

my 1997 f150 with 5.4 has the rough idle. only rough at idle runs great on take off. sounds like a bad *** cam. the check engine light is on. had it scaned, which was 1152 ( ho2 s 2 1 sensor switch idicates rich going to the shop 6-7-02. truck has 152,500 miles started about 2000 miles ago.

 

I have a 98 5.4 with 100000 mile and it jjust started to idle rough. It has also just shut off a couple of times. I havent had time to take it to the shop yet though.

 

Hey Roger I tried your fix to my surprise my truck is 100% better. I am due for a fuel filter change and also I will change my IAC valve this should take care of remaining occasional rough idle as my truck as 80,000 miles on it and evrything is still original. I will repeat procedure after repairs. I wanted to let you know the result but I could not remember where I had gotten the fix from.

In any event thanks for the info and also thanks to this great site which permits all of this information being shared.


sly

 

Sly,
I hope it keeps working for you. Thanks for the information.

 

My 99 4.2L F150 started it around 24k after i took it to Ford for tranny work (manual) cuz it wouldn't shift into gear. They made my truck shift nice and smooth, but it was idling rough as soon as i got it back. Then, I took it in to get the rough idle fixed...it worked great except the tranny won't shift into gear every so often again. A few days later the rough idle came back and my warranty ran out. Now I'm just gonna swap engines and transmissions as soon as I can. 460 crate engine and C6 sounds nice.

~Mark

 

HELLO ALL,
SORRY I HAVEN'T BEEN AROUND HERE THE LAST MONTH OR SO. UNFORTUNATELY ME AND MY WIFE LOST THE LIFE OF OUR
10 YEAR OLD SON ON MAY 20TH. AND HAVE BEEN DEALING WITH THIS ORDEAL SINCE MAY 10TH WHEN HE PASSED OUT WHILE AT SCHOOL. I WAS KINDA HOPING TO COME AROUND AND MAYBE FIND SOMEONE HAD FOUND A FIX TO OUR ROUGH IDLE PROBLEMS. ANYWAY I AM BACK AND STILL TRYING TO FIX MY ROUGH IDLE AND WILL PASS ON ANY INFORMATION I CAN.

 

i have 98 f-150 with a romeo 4.6 with 35,000 miles no problems yet but my drive to work is only 5 minutes im in serious trouble

 

36,

My deepest and most sincere sympathy goes to you and your family on the loss of your son.

Kevin

 

I have 99 with 105k miles on it and rough idle just started for me after a fuel filter change and will stall out sometimes when going very slow through parking lots. I have had it since about 98k miles so don't know if there was rough idle before.

 

THANKS AREA 52!!!!!!!!!!!