i have a 2004 F150 5.4 supercrew and curious if anyone has had this problem....When stomping the gas around 35 to 40 mph i get a couple "clunk" sounds then the truck goes, but if i stomp it any other time i get no noise, just at that speed. No vibrations, shifts smooth and power is fine but i do get major hesitation if i floor it around 50 mph between the 3k and 4k rpm range, after 4k it's fine...best way to describe it is that it feels like its not getting enough fuel and cuts in and out. When out of gear it revs fine... My worry is the popping sound, but it never does it any other time...Any insight would be greatly appreciated!

 

My 04 does this also, so I'm curious to here what others have to say....

 

I also have this when trying to pass. Not always but sometimes it seems to get all confused.

I get an opening, hit the penal to the floor to accelerate and the transmission down shifts with the engine kind of stumbling for about a second then it takes off like a bat out of hell.

Is this a part of having "fly by wire"? I am used to a throttle cable to a carb so the response is instant.

The only thing I could think of is that the computer keeps the engine from making power until the transmission is in the right gear and ready. It is really annoying as you need to punch it just before you want to pass or you will sit out in the passing lane a second before taking off. It doesn't seem to be as bad if you don't press to the floor but I was always of the understanding that punching the throttle to the floor is the proper signal to the computer you want max power for passing.

Of course this could just be me learning how to drive a completely computerized vehicle. I still remember the first time I drove a truck (as in big truck not these) with an electronic throttle instead of a mechanical one. It takes a little getting used to.

Any replies are appreciated.

 

I have a 2005 S-Crew F-150 and am having the same "problem." The only difference is mine comes between 15 - 30 mph. I dont know if this has to do with the 35" tires. It sounds bad but I have never had any problems and shifts smooth all other times. I tried explaining it to a friend who also has a 05 and he said his did the same thing however my friend with the 07 (His is stock though) doesnt have this happen.

 

I have an 05 5.4 with the 4R75W and it was very harsh on downshifts from 3 to 2 with 50% throttle around 30 mph. Complained many times to Ford. What solved it was Castrol Mercon V at the correct level. The trans was overfilled from the factory and I begged them to lower the fluid level, they never did. Once off warranty I did a clean & flush now it's perfect.

 

I have read about these issues several times now and I guess I lucked out because to date, I've not experienced any hesitations in my 2005 4x4 S.crew Lariat. Trans: 4R70E

Question 1: What is the condition of the ATF in your trucks?
Q2: Do you think this might be a spark plug issue?
Q3: Do you ever run the injector cleaner chemicals?

I was told by the 2 closest dealers that both have one of those fuel injector cleaner machines. How it works, I have no idea, but the fee isn't cheap. It's $79-89.00 but they allegedly hook up some machine that actually cleans the injectors, not just add some chemical to the fuel. I plan on doing it every 30K miles.

I buy the cheap Walmart brand injector cleaner at $1.77/bottle (12oz) that treats "up to 20 gallons" and is to be used about every 2500 miles.

I run 2 bottles of that stuff per tank about 1x/month.

I've juiced the motor on the highway and on some backroads beginning at various speeds and have only had 1 response in each case, which is an immediate downshift followed by acceleration without any hesitation, ever.

 

I have the exact same problem here. I took it in a few months ago and got a copy of a service bulletin saying that this was a normal condition, characteristic of the tranny. Do not attempt a fix at this time. This was about 6 months ago or so. I would take it in to see if a fix has been issued yet, but I am now out of warranty and they will hit me nearly $100 to find out. I spoke to friend of mine who works at a Ford dealer and he said he would check oasis and look for updates. So unless someone lets me know there is a reprogram, or the tranny falls out of the bottom, I am just going to deal with it. However, I replaced my fuel filter a few days ago (it was pretty clogged) and it seemed to have at least improved the condition.

 

i think these tranny's just suck. typical ford problem in my opinion. mine shift retarted also. like it doesn't know what to do sometimes.

 

I am running 2 bottles of injector cleaner since my last fill-up. It hasn't done it to me yet but I haven't been driving anywhere except to work. I might play with it some on the way to work tomorrow morning. At 4:45am there aren't many people around to pass. I'll just pretend.

Oh and I don't get the noise as reported by the OP. Mine just gets confused and stumbles for a bit before taking off like it's supposed to.

I've only had this truck for 2 months now. I checked the tranny fluid and it looks in good condition to me. No burnt smell from it. Maybe I'll get it changed when I get my first oil change in a month just to be sure. Who knows what the previous owner did to it other than regular oil changes...

 

the trannies are alittle retarded definately.

also think that if you guys would get a troyer tune over the stock computer tune and would notice a huge differnece in throttle lag.

mine tranny is starting to shudder once in a blue moon when trying to downshift which is starting to scare me alittle.

RYan

 

Try it with the Overdrive OFF. It won't do it. Well, atleast mine doesn't. Give it a try and let me know if your's is the same?????

 

How much is the troyer tune??

 

Pretty sure this is a driveshaft issue (ie the "clunk" around 2nd & 3rd).

I have had my slip yoke lubed on two occasions for this problem. If you search slip yoke, I believe there is a TSB on this. Some people have actually had their driveshafts replaced for this issue.

 

I have this issue also, and Ford replaced my driveshaft. The "clunk" was reduced, but i still get a big clunk at about 1/2 throttle going anywhere from 10-20 mph.

 

Mine feels like you are manually downshifting into 2nd. The clunck doesnt sound or feel like anything more than a really hard downshift. It's just really annoying. I am thinking about getting a tune and hoping that a change in the shift points will prevent this.