Ford4x4Lariat2005

Guys and Girls, long time lurker first time poster...

I have a 2005 Ford 5.4L Lariat Supercrew 4x4

I thought I could turn to my Ford brothers and sistes for advice, help, suggestions with my transmission problem knocking, thumping between 40-50mph range.

I have a 2005 F150, I am the original owner (this is my 5th ford truck, and proud to be a Ford man). Well, a about 6 months ago at about 95k miles, I began to notice a thump in the trans. when slowly accelerating and it only happen between 40-50 mph. (and very noticable) This also happens when I am cruising at 40-50mph in the city and the truck has to decide and downshift between the speeds 40-50 mph. When in this gear range, there is a noticable mulitlpe thumps (not sure if I want to call it slippage).

This also happens when I am on the freeway and set the cruise control on at 60mph, and the thump happens when I drive up a low grade on a freeway overpass, when the truck downshifts into a low gear to keep the same speed, the thump happens when it shifts. Since this began I drove like this for a bit, so I decided to have the trans. fluid drained w/ a new filter and filled. Well when I picked up the truck the fluid change made a big difference and my truck ran smooth as a whistle, and it was great. But recently (about 3 months later of everyday driving) the thumping has been happening again and in between the same speed ranges 40-50mph, and when on the freeway driving up a small grade when the truck has to downshift there is that thumping and hard shifting.

I have read on here that the solenoids could be the problem, and to have them replaced, or possibly the torque converter. Has anyone had this same problem, and if so what was the damage to get them replaced (I live in Houston, Texas) ? I thought of finding a used transmission and have found some with about 20k miles on them and just thinking of swaping it out, but I am afraid that the same thing will happen to the used trans. in a year or so if this is constant for problem with this trans.

Any ideas?

Thanks a bunch,
mc

ZX6ROCKET

100% the notorious 5.4 missfire not your transmission at all but it does feel like it. Mine was doing the exact same thing. Lol, Only under light throttle as well. Change your plugs and coils and it will be gone. Its misfiring multiple times once the trans tries to downshift due to the extra load. When did you change your plugs last? Mine was doing the EXACT same thing yours was and I changed the plugs and it was gone. Try the plugs and coils before you buy a trans!

freebird518

I second that, Same feeling in my truck. Changed the plugs and coils and it disappeared.

Ford4x4Lariat2005

Thanks for the reply guys,

My truck has 100k miles on it, and I have not changed the plugs or coils. yes, I know... I can hear my dad yelling at me that I should have had them changed every 50k or 40k.

I have not heard of this 5.4 misfire, (maybe that is why I have had ENGINE FAIL SAFE MODE) come on my warning center twice within the last year and half (thoughts?)

Either way, I will have the plugs and coils changed out this week and I will report back.

Thanks

ZX6ROCKET

In that case your truck will be fixed this week! report back your happiness! good luck!

gingertooth

what kind of plugs would you guys recommend???? i'm getting it too.

Ford4x4Lariat2005

Ok guys, I had my truck looked at by a guy here in Houston that has an outstanding reputation among our community. We went for a drive and he felt exactly what I was described above. Apparently I have a misfire and one of my coils is bad so I am going to get it replaced and he recommended to change out plugs and coil packs.

I would do this on my own, but I live in an apartement. He is going to soak the plugs overnight and hit them the next day to remove them. He described the process exactly what the sticky describes on how to remove the plugs (I have the 3 valve 5.4). So he is aware of how to remove them. He also has experience with the Lisle Tool used to remove the lower half in the event it breaks.

I think his quote maybe on the high side, but I know he does dam good work, and that piece of mind is work this $700

He will be using the platnum motorcraft plugs (one piece I believe)

I'll get back and let yall know what happen.

Thanks a lot guys,

kevhead75

Motorcraft

ZX6ROCKET

Is that for just the plugs or the coils too? Make sure he puts nothing in there but the oem factory parts. No pepboys coils or plugs. Go with true motorcraft plugs and DG511 coils

Ford4x4Lariat2005

The price I was quoted was to replace all plugs with Motorcraft (platnum one piece), soak existing plugs overnight and first thing the next morning, run an injector cleaner prior to removing them / soaking, Using Seafoam (amszoil type), replacing all boots, and replacing one coil that went bad.

I can't wait to feel my baby again on the freeway running like new.