about 8k miles ago (27k total) my 03 F150 SCrew 5.4 started idling rough like it had a slight miss. I took it to Ford, under warranty, and they said nothing was wrong and reset some computer. It felt the same, but I drove it around for a while and took it back in for the same concern. This time they replaced some IAC device and said problem solved. Not fixed. Took it back in some time later and they replaced the EGR and said fixed. No, still not fixed. Took it in again, this time they replaced some coils and said they got it. Well they didn't, and the next time I took it in they said nothing is wrong. So I asked to meet with a Ford Zone Rep and he looked it over and agreed that it does idle rough, says its normal, and also showed me on his computer where some of the cylinders are very slightly dropping off due to a fuel cut back to keep the rpm even. The rpm varies between 615 and 629. My question is am I getting the run around or is there a fix to the problem? sorry I got a little long winded....... thanks

 

My 98 F150 5.4 used to have a rough idle untill I cleaned the MAF. I disconnected the battery while I had it apart. I still get a rough idle occasionally 2 to 3 minutes after the truck has started . It almost feels like it's going to stall but nevewr does. I think it is the IAC but I cannot get it off. It has these usless philips screws holding it on that I can't loosen.

Rick

 

rptalin, I thought the screws were torx heads. You may want to check it out.

MarkManz,

Not sure where you have a problem with the idle. 14 rpm doesn't seem a big deal to me. My 4.2, V6 has about a 50 rpm variance. It's also a little rough, but all that I've seen and heard are a little rough. Don't know what you dealing with but from your description it sounds normal.

 

I'm pretty sure the screws are philips. I will have another look tomorrow, maybe I'm looking at something else.

Rick

 

The truck is still under warranty so I was hoping Ford would take care of it. Maybe I will try and clean the MAF. I would not be making a big deal but the truck just started doing this. It ran smooth before and my hunting partner's 02's 5.4 truck idles ok as well. thanks